[go: up one dir, main page]

WO2023075704A2 - Catalyseurs - Google Patents

Catalyseurs Download PDF

Info

Publication number
WO2023075704A2
WO2023075704A2 PCT/SG2022/050783 SG2022050783W WO2023075704A2 WO 2023075704 A2 WO2023075704 A2 WO 2023075704A2 SG 2022050783 W SG2022050783 W SG 2022050783W WO 2023075704 A2 WO2023075704 A2 WO 2023075704A2
Authority
WO
WIPO (PCT)
Prior art keywords
hours
vol
rpm
supported catalyst
catalyst
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/SG2022/050783
Other languages
English (en)
Other versions
WO2023075704A3 (fr
Inventor
Bin Liu
Hongbin YANG
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nanyang Technological University
Original Assignee
Nanyang Technological University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nanyang Technological University filed Critical Nanyang Technological University
Publication of WO2023075704A2 publication Critical patent/WO2023075704A2/fr
Publication of WO2023075704A3 publication Critical patent/WO2023075704A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/02—Hydrogen or oxygen
    • C25B1/04—Hydrogen or oxygen by electrolysis of water
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/33—Electric or magnetic properties
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/054—Electrodes comprising electrocatalysts supported on a carrier
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/055—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the substrate or carrier material
    • C25B11/057—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the substrate or carrier material consisting of a single element or compound
    • C25B11/067—Inorganic compound e.g. ITO, silica or titania
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/075—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound
    • C25B11/089—Alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/89—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals
    • B01J23/8933—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals also combined with metals, or metal oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/8993—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals also combined with metals, or metal oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with chromium, molybdenum or tungsten
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/10—Process efficiency
    • Y02P20/133—Renewable energy sources, e.g. sunlight

Definitions

  • the present disclosure generally relates to catalysts, in particular, catalysts for oxygen evolution reactions.
  • the present disclosure also relates to a method of producing such catalysts.
  • the present disclosure further relates to uses of such catalysts.
  • PEM proton exchange membrane
  • the OER In water electrolysis systems, the largest consumer of energy is the OER due to the high overpotential required by commercial catalysts, and thus most of the energy in such hydrogen production systems are accordingly dedicated to the OER half-cell process.
  • the high cost of the OER anode catalyst is the main barrier that greatly restricts the large-scale application of the PEM water electrolysis technology for hydrogen gas.
  • IrOx has been commercially used as catalysts.
  • Ir is an expensive metal, and such IrOx catalysts are not stable in acidic media, which is commonly found in PEM electrolyzers.
  • commercial catalysts and electrodes comprising the same often need to be replaced frequently, further adding to the huge operational costs of the increased energy consumption.
  • Other metals have been tested, however their costs are comparable to Ir, and thus the costs are hardly alleviated. Additionally, such catalysts formed with other metals still face the same problem of large overpotentials as well as instability in acidic media.
  • a supported catalyst comprising Ml, M2, TM, and SI, wherein:
  • M 1 and M2 are metals independently selected from the group consisting of Ru, Pd, Ir, Pt, Au, Os, Re, Rh, Ag, Mo, Tc, and Nb;
  • TM is a transition metal
  • S 1 is a support; wherein the weight ratio of M1:M2:TM is in the range of about 1 : 2-10 : 2-10; the weight ratio of (M1+M2):S1 is in the range of about 1 : 5-20; and Ml, M2, and TM are different.
  • the catalysts of the present disclosure may contain strong interactions between the metals and the support, which results in an unprecedented stability in acidic media. This advantageously allows the catalysts to operate for a longer time and thus there is less need to replace the catalysts frequently.
  • the catalysts of the present disclosure may also require a significantly lower overpotential to drive the OER. This advantageously translates into both a better energy efficiency of the catalyst as well as lower energy costs.
  • the catalysts of the present disclosure may also be easily tuned by introducing various dopants to adjust the various characteristics of the catalysts, such as the overpotential, pH stability in solution or conversion efficiency.
  • the catalysts of the present disclosure may also be compatible with commercial fabrication processes of PEM water electrolyzers and other electrochemical devices, and hence may be easily and advantageously taken up and made use of in industry without any difficulty.
  • a process of preparing a supported catalyst comprising the steps of: a) preparing a mixture comprising an organometallic compound of Ml, an organometallic compound of M2, an organometallic compound of TM, and SI, wherein:
  • M 1 and M2 are metals independently selected from the group consisting of Ru, Pd, Ir, Pt, Au, Os, Re, Rh, Ag, Mo, Tc, and Nb;
  • TM is a transition metal
  • S 1 is a support; wherein the weight ratio of M1:M2:TM is in the range of about 1 : 2-10 : 2-10; the weight ratio of (M1+M2):S1 is in the range of about 1 : 5-20; and
  • step (b) ball-milling the mixture of step (a) at a rotation speed of about 200 rpm to about 900 rpm for a duration of about 1 hour to about 5 hours to form a ball-milled mixture, and c) pyrolyzing the ball-milled mixture of step (b) at a temperature of about 300 °C to about 600 °C for a duration of about 1 hour to about 5 hours to form a pyrolyzed product.
  • the present disclosure provides for a robust and highly active catalyst that is produced through ball milling.
  • the presently disclosed catalysts are surprisingly stable in acidic media.
  • Ball-milling is both simple and environmentally friendly as it does not require significant energy input and does not require any solvent for mixing.
  • Ball-milling can also be fine-tuned to adjust metal-support interactions and produce strain and defects in the metal components, which cannot be accomplished by conventional methods such as impregnation, coprecipitation, sol-gel, etc.
  • the strain and/or defects introduced during the ball milling process may also enhance the interaction between the metals and the support, thus further improving the stability of catalysts produced by the method disclosed herein.
  • the presently disclosed method may also be easily scaled for large-scale synthesis. For example, ball-milling, pyrolysis and reduction may each be performed either in batch mode, or in flow-mode if necessary.
  • Current industrial infrastructure may also be easily and advantageously modified to fit the process requirements.
  • the presently disclosed method may comprise a reduction step.
  • the reduction step may comprise heating the product in a reductive atmosphere which may advantageously expose active sites that were previously covered by the oxide layer. Additionally, the reduction may also advantageously increase the porosity of the catalyst, further increasing its surface area and thus efficiency.
  • the presently disclosed method of producing the catalysts may also not require the use of any solvents, and thus advantageously reduces the amount of liquid waste that needs to be treated or disposed of. By avoiding the use of solvents, the problem of treating such toxic liquid waste is also thus advantageously eliminated.
  • the catalysts of the present invention may comprise expensive metals (such as iridium, ruthenium and palladium) in a much smaller weight% as compared to commercial and conventional catalysts which makes the catalyst of the present invention much more cost effective.
  • metal precursors are advantageously easier to handle as compared to the metallic elements themselves.
  • transition metal refers to a metal that is found in the d-block series of the periodic table.
  • support refers to any material which has good electron conductivity to which the catalyst is applied, and can support the same catalyst during reaction.
  • the support may provide a high surface area, as well as provide additional chemical and mechanical stability to the catalyst.
  • the phrase "at least,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements.
  • This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified.
  • At least one of A and B can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
  • the term "about”, in the context of concentrations of components of the formulations, typically means +/- 10% of the stated value, more typically +/- 9% of the stated value, more typically +/- 8% of the stated value, more typically +/- 7% of the stated value, more typically +/- 6% of the stated value, more typically +/- 5% of the stated value, more typically +/- 4% of the stated value, more typically +/- 3% of the stated value, more typically, +/- 2% of the stated value, even more typically +/- 1% of the stated value, and even more typically +/- 0.5% of the stated value.
  • range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosed ranges. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.
  • FIG. 1 A first figure.
  • Fig. 1 is a scheme depicting a general method of producing catalysts in accordance with an embodiment of the present invention.
  • Fig. 2a is a graph showing X-Ray Diffraction (XRD) patterns of various Ir R u-, based catalysts of the present invention, commercial catalysts, as well as those of WO3 and reduced WO3 (WO3-H2) as reference.
  • XRD X-Ray Diffraction
  • Fig. 2b is a Scanning Electron Microscopy (SEM) image of Iri RU3CO3-WO3-R from Example 1c.
  • Fig. 3 are spectra showing the X-ray Photoelectron Spectroscopy (XPS) of various catalysts of the present invention, (a) Survey, (b) O Is, (c) Ir 4f, (d) Ru 3d, (e) Co 2p and (f) W 4f.
  • XPS X-ray Photoelectron Spectroscopy
  • Fig. 4 are Transmission Electron Microscopy (TEM) and High-Resolution TEM (HR-TEM) images of the catalysts of the present invention, (a) 20 nm scale and (b) 2 nm scale for Iri RU3CO3-WO3; and (c) 20 nm scale and (d) 2 nm scale for hjRu3Co3-WC>3-R-450 °C.
  • TEM Transmission Electron Microscopy
  • HR-TEM High-Resolution TEM
  • Fig. 5a is a graph showing the Linear Sweep Voltammetry (LSV) curves of various catalysts of the present invention as well as that of a conventional catalyst as reference.
  • FIG. 5B is a graph showing the Linear Sweep Voltammetry (LSV) curves of various catalysts of the present invention as well as that of a conventional catalyst as reference.
  • Fig. 5b is a graph showing the corresponding Tafel plot of the results depicted in Fig. 5a.
  • Fig. 5c is a graph showing Linear Sweep Voltammetry (LSV) curves of various catalysts of the present invention as well as that of a conventional catalyst as reference, wherein values have been normalised to the mass of noble metal present.
  • LSV Linear Sweep Voltammetry
  • Fig. 5d is a graph showing the measured current density of the various catalysts of the present invention as well as that of a conventional catalyst at various overpotentials.
  • Fig. 6 is a graph showing the chronopotentiometric curves of a catalyst of the present invention, with that of a conventional catalyst as reference.
  • Ml precursor (100), M2 precursor (102), transition metal precursor (104) as well as support (106) undergo ball-milling (108).
  • the ball-milled mixture is then subjected to thermal treatment (110) to produce a supported catalyst (112) of the present invention.
  • an optional further reduction step to reduce the oxygen/oxide content of the supported catalyst.
  • the present disclosure provides for a supported catalyst comprising M 1 , M2, TM, and S 1 , wherein:
  • M 1 and M2 are metals independently selected from the group consisting of Ru, Pd, Ir, Pt, Au, Os, Re, Rh, Ag, Mo, Tc, and Nb;
  • TM is a transition metal
  • S 1 is a support; wherein the weight ratio of M1:M2:TM is in the range of about 1 : 2-10 : 2-10; the weight ratio of (M1+M2):S1 is in the range of about 1 : 5-20; and
  • Ml, M2, and TM are different.
  • Electron transport between the support and metals can affect the charge density and distribution of metal species, which will thus affect the catalytic properties of the catalyst.
  • Different supports can be used, for example, metal oxides such as TiOj, S11O2, WO3 amongst others, metal carbides such as TiC, WC, W2C, M02C amongst others, or metal nitrides such as TiN, TaN, amongst others.
  • the support (SI) may be a conductive support.
  • the support (SI) may be a thermally conductive support.
  • the support (SI) may be WO3, SiCL, AI2O3, carbon, TiCL, Z1O2, SiCh-AhCh, montmorillonite, SiOj-TiOj, tungstated ZrOj, zeolites, V2O5, MoOs, S11O2, TiC, WC, W2C, M02C, TiN, TaN, or mixtures and combinations thereof.
  • the support may be SiO2-
  • the weight ratio of the metals in the catalyst may comprise various ratios.
  • the weight ratio ofMl:M2:TM maybe inarange of about 1: 2-10: 2-10, about 1: 2-9: 2-10, about 1: 2-8: 2-10, about 1: 2-7: 2-10, about 1: 2-6: 2-10, about 1: 2-5: 2-10, about 1: 2-4: 2-10, about 1: 2-3: 2-10, about 1: 3- 10: 2-10, about 1: 4-10: 2-10, about 1: 5-10: 2-10, about 1: 6-10: 2-10, about 1: 7-10: 2-10, about 1: 8-10: 2-10, about 1: 9-10: 2-10, about 1: 2-10: 2-9, about 1: 2-10: 2-8, about 1: 2-10: 2-7, about 1: 2- 10: 2-6, about 1: 2-10: 2-5, about 1: 2-10: 2-4, about 1: 2-10: 2-3, about 1: 2-10: 3-10, about 1: 2-10: 4-10, about 1: 2-10:
  • the term “about” typically means +/- 10% of the stated value. This applies to all ranges mentioned herein. Hence, for example, when it is mentioned that the weight ratio of M1:M2:TM may be about 1:3 : 3, this includes a range of 0.9- 1.1 : 2.7-3.3 : 2.7-3.3.
  • the weight ratio of M1:M2:TM may be in the range of about 0.9- 1.1 : 2.7-3.3 : 2.7-3.3, about 1 : 2.7-3.2 : 2.7-3.2, 1 : 2.7-3.1 : 2.7-3.1, 1 : 2.7-3 : 2.7-3, 1 : 2.7-2.95 : 2.7-2.95, 1 : 2.7-2.94 : 2.7-2.94, 1 : 2.7-2.8 : 2.7-2.8, 1 : 2.7-2.9 : 2.7-2.9, about 1 : 2.8-3.3 : 2.8-3.3, about 1 : 2.8.2-3.3 : 2.8.2-3.3, about 1 : 2.85-3.3 : 2.85-3.3, about 1 : 2.9-3.3 : 2.9-3.3, about 1 : 2.94- 3.3 : 2.94-3.3, about 1 : 2.95-3.3 : 2.95-3.3, about 1 : 3-3.3 : 3-3.3, about 1 : 3.1-3.3 :
  • the weight ratio of M1:M2:TM may be from about 1 : 1 : 1 to about 1 : 10 : 1, from about 1 : 1 : 1 to about 1 :7: 1, from about 1 : 1 : 1 to about 1:5: 1, from about 1 : 1 : 1 to about 1:3: 1, from about 1 : 1 : 1 to about 1:2: 1, from about 1 : 2 : 1 to about 1 : 10 : 1, from about 1 : 2 : 1 to about 1:7: 1, from about 1:2: 1 to about 1:5: 1, from about 1 :2: 1 to about 1:3: 1, from about 1 : 3 : 1 to about 1 : 10 :
  • the weight ratio of M1:M2:TM may be at most about 1 : 1 : 1, at most about 1 : 2 : 1, at most about 1 : 3 : 1, at most about 1 : 5 : 1, at most about 1 : 7 : 1, at most about 1 : 10 : 1, at most about 1 : 1 :
  • the weight ratio of M1:M2:TM may be about 1 : 1 : 1, about 1 : 2: 1, about 1 : 3 : 1, about 1 :5 :
  • the present disclosure may provide for a catalyst wherein the content of the metal elements Ml, M2, and TM may be in the range of about 1 wt% to about 2 wt%, about 3 wt% to about 6 wt%, and about 3 wt% to 6 wt%, respectively.
  • the content of Ml may be in the range of about 1 wt% to about 2 wt%, about 1 wt% to about 1.9 wt%, about 1 wt% to about 1.8 wt%, about 1 wt% to about 1.7 wt%, about 1 wt% to about 1.6 wt%, about 1 wt% to about 1.5 wt%, about 1 wt% to about 1.4 wt%, about 1 wt% to about 1.3 wt%, about 1 wt% to about 1.2 wt%, about 1 wt% to about 1.1 wt%, about 1.1 wt% to about 2 wt%, about 1.2 wt% to about 2 wt%, about 1.3 wt% to about 2 wt%, about 1.4 wt% to about 2 wt%, about 1.5 wt% to about 2 wt%, about
  • 1.7 wt% or about 1 wt%, about 1.1 wt%, about 1.2 wt%, about 1.3 wt%, about 1.4 wt%, about 1.5 wt%, about 1.6 wt%, about 1.7 wt%, about 1.8 wt%, about 1.9 wt%, about 2 wt%, or any ranges or values therebetween.
  • the content of M2 may be in the range of about 3 wt% to about 6 wt%, about 3.5 wt% to about 6 wt%, about 4 wt% to about 6 wt%, about 4.5 wt% to about 6 wt%, about 4.8 wt% to about 6 wt%, about 5 wt% to about 6 wt%, about 5.5 wt% to about 6 wt%, about 3 wt% to about 5.5 wt%, about 3 wt% to about 5 wt%, about 3 wt% to about 4.8 wt%, about 3 wt% to about 4.5 wt%, about 3 wt% to about 4 wt%, about 3 wt% to about 3.5 wt%, about 3.5 wt% to about 5.5 wt%, about 4 wt% to about 5 wt%, or about 3 wt%, about 3.2 wt%, about 3.4 wt%
  • the content of M3 may be in the range of about 3 wt% to about 6 wt%, about 3.5 wt% to about 6 wt%, about 4 wt% to about 6 wt%, about 4.5 wt% to about 6 wt%, about 5 wt% to about 6 wt%, about 5.5 wt% to about 6 wt%, about 3 wt% to about 5.5 wt%, about 3 wt% to about 5 wt%, about 3 wt% to about
  • the present disclosure may provide for a catalyst, wherein the weight ratio of M1:M2:TM is in the range of about 1: 2-10 : 2-10.
  • the present disclosure may also provide for a catalyst, wherein the weight ratio of M1:M2:TM is in the range of about 1: 2-5 : 2-5.
  • the present disclosure may provide for a catalyst, wherein the weight ratio of M1:M2:TM is about 1: 3 : 3, or about 1: 2.82: 2.94.
  • the weight ratio of the metals M1+M2 in the catalyst may be related to the weight of the support (S I).
  • the weight ratio of (M1+M2):S1 may be at least about 1 : 3, at least about 1 : 5, at least about 1 : 10, at least about 1 : 15, at least about 1 : 20, at least about 1 : 30, at least about 1 : 50, or from about 1 : 3 to about 1 : 50, from about 1 : 3 to about 1 : 30, from about 1 : 3 to about 1 : 20, from about 1 : 3 to about 1 : 15, from about 1 : 3 to about 1 : 10, from about 1 : 3 to about 1 : 5, from about 1 : 5 to about 1 : 50, from about 1 : 5 to about 1 : 30, from about 1 : 5 to about 1 : 20, from about 1 :
  • the weight ratio of the support may be about 10 times
  • the weight ratio of (M1+M2):S1 may be about 1 : 5-20, about 1 : 5-18, about 1 : 5-16, about 1 : 5-14, about 1 : 5-12, about 1 : 5-10, about 1 : 5-8, about 1 : 8-20, about 1 : 10-20, about 1 : 12-20, about 1 : 14-20, about 1 : 16-20, about 1 : 18-20, or any ranges or values therebetween.
  • the weight ratio of (M1+M2):S1 may be from about 1:5 to about 1:20.
  • the weight ratio of (M1+M2):S1 may be from about 1:5 to about 1:15.
  • the weight ratio of (M1+M2):S1 may be about 1:10.
  • composition of the final products can be tuned by the ratio of metal elements to the support in the precursor mixture.
  • the composition of the metals and the support in the catalyst may also be expressed in terms of either a molar ratio, or a weight ratio.
  • the molar ratio of the metals and the support M1:M2:TM:S1 may be in a range of at least about 1 : 2 : 5: 10, at least about 1 : 3 : 5: 10, at least about 1 : 5.7 : 5: 10, at least about 1 : 6 : 5: 10, at least about 1 : 10 : 5: 10, at least about 1 : 2:5: 20, at least about 1 : 3 : 5: 20, at least about 1 : 5.7 : 5: 20, at least about 1 : 6: 5: 20, at least about 1 : 10 : 5: 20, at least about 1 : 2:5: 33.2, at least about 1 : 3 : 5: 33.2, at least about 1 : 5.7 : 5: 33.2, at least about 1 : 6: 5: 33.2, at least about 1 : 10 : 5: 33.2, at least about 1 :2:5: 34.6, at least about 1 : 3 :5: 34.6, at least about 1 : 3 :
  • the molar ratio of the metals and the support M1:M2:TM:S1 may be from about 1 : 2 : 5: 10 to about 1 : 10 : 5: 10, from about 1 :2:5: 10 to about 1 : 6 : 5: 10, from about 1 : 2 : 5: 10 to about 1 : 5.7 : 5: 10, from about 1 : 2 : 5: 10 to about 1 : 3 : 5: 10, from about 1 : 3 : 5: 10 to about 1 : 10 : 5: 10, from about 1 : 3 : 5: 10 to about 1 : 6 : 5: 10, from about 1 : 3 : 5: 10 to about 1 : 5.7 : 10: 10, from about 1 : 5.7 : 10 to about 1 : 10 : 5: 10, from about 1 : 5.7 : 10 to about 1 : 10 : 5: 10, from about 1 : 5.7 : 10 to about 1 : 10 : 5: 10, from about 1 : 5.7 : 10 to about
  • the molar ratio of the metals and the support M1:M2:TM:S1 may be at most about 1 : 2 : 5: 10, at most about 1 : 3 : 5: 10, at most about 1 : 5.7 : 5: 10, at most about 1 :6:5: 10, at most about 1 : 10 : 5: 10, at most about 1 :2:5: 20, at most about 1 : 3 :5: 20, at most about 1 : 5.7 : 5: 20, at most about 1 :6: 5: 20, at most about 1 : 10: 5: 20, at most about 1 :2:5: 33.2, at most about 1 : 3 : 5: 33.2, at most about 1 : 3 : 5: 33.2, at most about 1 : 3 : 5: 33.2, at most about
  • the molar ratio of the metals and the support M1:M2:TM:S1 may be about 1 : 2 : 5: 10, about 1 : 3 : 5: 10, about 1 : 5.7 : 5: 10, about 1 : 6 : 5: 10, about 1 : 10 : 5: 10, about 1 :2:5: 20, about 1 : 3 :5: 20, about 1 : 5.7 : 5: 20, about 1 :6:5: 20, about 1 : 10 : 5: 20, about 1 :2:5: 33.2, about 1 :3 :5: 33.2, about 1 : 5.7 : 5: 33.2, about 1 :6:5: 33.2, about 1 : 10 : 5: 33.2, about 1 : 2: 5: 34.6, about 1 : 3 :5: 34.6, about 1 : 5.7 : 5: 34.6, about 1 :6:5: 34.6, about 1 : 10 : 5: 34.6, about 1 :2:5: 50, about 1
  • the molar ratio of the metal elements and support in the catalyst may be about 1: 2-10 : 5-20 : 10- 100.
  • the molar ratio of the metal elements and support in the catalyst may be about 1 : 6 : 10 : 34.6.
  • the molar ratio of the metal elements and support in the catalyst may be about 1 : 5.7 : 9.77 : 33.2.
  • the content of the metal element in the support (S 1) may be in the range of about 40 wt% to about 60 wt%, about 45 wt% to about 60 wt%, about 50 wt% to about 60 wt%, about 55 wt% to about 60 wt%, about 40 wt% to about 55 wt%, about 40 wt% to about 50 wt%, about 40 wt% to about 45 wt%, about 45 wt% to about 55 wt%, about 50 wt% to about 55 wt%, or about 40 wt%, about 42 wt%, about 44 wt%, 46 wt%, about 48 wt%, about 50 wt%, about 52 wt%, about 54 wt%, about 56 wt%, about 58 wt%, about 60 wt%, or any ranges or values therebetween.
  • the catalysts of the present invention comprise these expensive metals in a much smaller weight% as compared to commercial and conventional catalysts.
  • the metals M1+M2 may make up the catalyst in a range of at least about 2 wt%, at least about 3 wt%, at least about 4 wt%, at least about 5 wt%, at least about 6 wt%, at least about 7 wt%, at least about 8 wt%, at least about 9 wt%, at least about 10 wt%, at least about 12 wt%, at least about 15 wt%, at least about 17 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%, at least about 35 wt%, at least about 40 wt%, at least about 50 wt%; or from about 2 wt% to about 50 wt%, from about 2 wt% to about 40 wt%, from about 2 wt% to about 35 wt%, from about 2 wt% to about 30 wt%, from about 2 wt% to about 25 wt
  • 6 wt% to about 40 wt% from about 6 wt% to about 35 wt%, from about 6 wt% to about 30 wt%, from about 6 wt% to about 25 wt%, from about 6 wt% to about 20 wt%, from about 6 wt% to about 17 wt%, from about 6 wt% to about 15 wt%, from about 6 wt% to about 12 wt%, from about 6 wt% to about 10 wt%, from about 6 wt% to about 9 wt%, from about 6 wt% to about 8 wt%, from about 6 wt% to about 7 wt%, from about 7 wt% to about 50 wt%, from about 7 wt% to about 40 wt%, from about 7 wt% to about 35 wt%, from about 7 wt% to about 30 wt%, from about 7 wt% to about 25 wt%, from about
  • metals capable of catalyzing an OER reaction may be used.
  • metals like Ru, Pd, Ir, Pt, Au, Os, Re, Rh, Ag, Mo, Tc, and Nb may be used as Ml and M2 in the catalysts of the present invention.
  • the metals may be Ru, Pd, Ir, Pt, Au, Os, Re, Rh, Ag, Mo, Tc, and Nb.
  • the metals may be Ru, Pd, Ir, and Pt.
  • metal precursors may be used instead of providing the metals as-is for preparing the catalysts.
  • metal precursors advantageously allows for easier handling of the compounds, especially at micromolar or nanomolar scale. Additionally, precursors of the metals may make the reagents easier to weigh, and prevent unwanted metallic interactions during the preparation phase, for example, during ball-milling or pyrolysis. The use of such precursors also helps to improve the porosity and surface area of the catalysts after pyrolysis, as the salts are pyrolyzed from the mixture, leaving behind pure metals and empty spaces in the catalyst which increase surface area.
  • precursors can be used, like organometallic compounds of metals, such as metal carbonyl compounds, metal ethylene complexes, metal-acetylacetonates, metal-acetates, metal cyanide compounds, metal-bis(acetylacetonate)s, cyclopentadienyl metal compounds or mixtures and combinations thereof.
  • metals such as metal carbonyl compounds, metal ethylene complexes, metal-acetylacetonates, metal-acetates, metal cyanide compounds, metal-bis(acetylacetonate)s, cyclopentadienyl metal compounds or mixtures and combinations thereof.
  • Other precursors may also be used, as long as they can be removed cleanly during the pyrolysis step.
  • transition metals may be used, that instead of reducing the electrocatalytic properties of the catalyst, may instead enhance them. Such transition metals can also further adjust the catalytic performance of the prepared electrocatalysts.
  • the transition metal may be a Group III-XII transition metal.
  • the transition metal may be a Group IV- VII transition metal.
  • the transition metal may be a Group IV-V transition metal.
  • the transition metal may be Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au or Hg.
  • the transition metal may be Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag or Cd.
  • the transition metal may be Mn, Fe, Co, Ni or Cu.
  • the transition metal may be Co.
  • the catalysts of the present invention may have advantageously lower oxygen and/or oxide content after reduction in a reductive environment.
  • the chemical states of the surface metal elements can change from the oxidized state to either partially oxidized or even the pure metallic state.
  • Such reduced surface metal elements are particularly conducive and advantageously facilitate the OER process even more than other commercial catalysts.
  • the oxygen and/or oxide content in the catalyst before reduction may be in a range of at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%, at least about 35 wt%, at least about 40 wt%, at least about 43 wt%, at least about 45 wt%, at least about 47 wt%, at least about 49 wt%, at least about 50 wt%, at least about 52 wt%, at least about 53 wt%, at least about 55 wt%, at least about 57 wt%, at least about 60 wt%, at least about 63 wt%, at least about 66 wt%, at least about 69 wt%, at least about 70 wt%; or from about 10 wt% to about 70 wt%, from about 10 wt% to about 69 wt%, from about 10 wt% to about
  • the catalyst has an oxygen and/or oxide content of less than about 60% before reduction. In some further preferred embodiments, the catalyst has an oxygen and/or oxide content of less than about 50% before reduction. In yet some other preferred embodiments, the catalyst has an oxygen and/or oxide content of less than about 49% before reduction. In some further preferred embodiments, the catalyst has an oxygen and/or oxide content of less than about 43% before reduction.
  • the oxygen and/or oxide content in the catalyst after reduction may be in a range of at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%, at least about 35 wt%, at least about 40 wt%, at least about 43 wt%, at least about 45 wt%, at least about 47 wt%, at least about 49 wt%, at least about 50 wt%, at least about 52 wt%, at least about 53 wt%, at least about 55 wt%, at least about 57 wt%, at least about 60 wt%, at least about 63 wt%, at least about 66 wt%, at least about 69 wt%, at least about 70 wt%; or from about 10 wt% to about 70 wt%, from about 10 wt% to about 69 wt%, from about 10 wt% to about
  • the catalyst has an oxygen and/or oxide content of less than about 60% after reduction. In some further preferred embodiments, the catalyst has an oxygen and/or oxide content of less than about 50% after reduction. In yet some other preferred embodiments, the catalyst has an oxygen and/or oxide content of less than about 49% after reduction. In some further preferred embodiments, the catalyst has an oxygen and/or oxide content of less than about 43% after reduction.
  • the catalysts of the present disclosure may also be easily tuned by introducing various dopants (such as sulfur, selenium, or phosphorous) to adjust the various characteristics of the catalysts, such as the overpotential, pH stability in solution or conversion efficiency.
  • the dopant(s) may be added in an amount of about 0.1 wt% to about 5 wt%, about 0.5 wt% to about 5 wt%, about 1 wt% to about 5 wt%, about 2 wt% to about 5 wt%, about 3 wt% to about 5 wt%, about 4 wt% to about 5 wt%, about 0.1 wt% to about 4 wt%, 0.1 wt% to about 3 wt%, 0.1 wt% to about 2 wt%, 0.1 wt% to about 1 wt%, 0.1 wt% to about 0.5 wt%, or any ranges or values therebetween.
  • the present disclosure provides for a catalyst, wherein Ml is Ir, M2 is Ru, TM is Co, SI is WO3, the weight ratio of M1:M2:TM is about 1:3:3, and the weight ratio of (M1+M2):S1 is about 1:10, wherein the supported catalyst has an oxygen and/or oxide content of less than about 50%.
  • the present disclosure also provides for a process of preparing a supported catalyst, the process comprising the steps of: a) preparing a mixture comprising an organometallic compound of Ml, an organometallic compound of M2, an organometallic compound of TM, and SI, wherein:
  • Ml and M2 are metals independently selected from the group consisting of Ru, Pd, Ir, Pt, Au, Os, Re, Rh, Ag, Mo, Tc, and Nb;
  • TM is a transition metal
  • S 1 is a support; wherein the weight ratio of M1:M2:TM is in the range of about 1 : 2-10 : 2-10; the weight ratio of (M1+M2):S1 is in the range of about 1 : 5-20; and
  • step (b) ball-milling the mixture of step (a) at a rotation speed of about 200 rpm to about 900 rpm for a duration of about 1 hour to about 5 hours to form a ball-milled mixture, and c) pyrolyzing the ball-milled mixture of step (b) at a temperature of about 300 °C to about 600 °C for a duration of about 1 hour to about 5 hours to form a pyrolyzed product.
  • the mixture of metal (Ml, M2, TM) precursors as well as the support may be first ground into a homogenous mixture using ball-milling at different rotating speeds for different time durations under controlled ambient conditions, which could for example be reductive ambient or oxidizing ambient conditions.
  • milling balls may be used, for example zirconia balls, ceramic balls, alumina balls, steel balls, tungsten carbide balls, or agate balls.
  • jars may also be used, for example nylon jars.
  • zirconia balls are used in the ball milling step (b).
  • nylon jars are used in the ball milling step (b).
  • Ball-milling is a low energy process and allows the components in the mixture to mix uniformly, and be grounded as well to very fine nanoparticles.
  • tuning the parameters of the ball-milling process for example by adjusting the atmosphere of the ball-milling to either oxidizing or reducing, or by tuning other parameters of the process such as rotating speed, duration, ambient temperature, or by adding other materials, components and/or materials, the physiochemical properties of the ball-milled mixture can be tuned and adjusted. Further, various crystalline properties may even be imparted by the ball-milling process to the catalyst after ball-milling in combination with pyrolyis.
  • surfactants could also be introduced to tune or to further improve the interaction between the metal components and the support.
  • the present disclosure provides for a method of producing a catalyst, wherein ball-milling step (b) is performed in an oxidizing or reducing atmosphere.
  • the present disclosure also provides for a method of producing a catalyst, wherein ball-milling step (b) is performed in an oxidizing atmosphere.
  • the present disclosure further provides for a method of producing a catalyst, wherein ball-milling step (b) is performed in an reducing atmosphere.
  • the ball-milling step (b) may be performed at a rotation speed in a range of at least about 100 rpm, at least about 150 rpm, at least about 200 rpm, at least about 250 rpm, at least about 300 rpm, at least about 350 rpm, at least about 400 rpm, at least about 450 rpm, at least about 500 rpm, at least about 600 rpm, at least about 700 rpm, at least about 800 rpm, at least about 900 rpm, at least about 1000 rpm; or from about 100 rpm to about 1000 rpm, from about 100 rpm to about 900 rpm, from about 100 rpm to about 800 rpm, from about 100 rpm to about 700 rpm, from about 100 rpm to about 600 rpm, from about 100 rpm to about 500 rpm, from about 100 rpm to about 450 rpm, from about 100 rpm to about 400 rpm, from about 100 rpm to about 350 r
  • the ball-milling step (b) is performed for a duration range of at least about 0.5 hours, at least about 1 hour, at least about 1.5 hours, at least about 2 hours, at least about 2.5 hours, at least about 3 hours, at least about 3.5 hours, at least about 4 hours, at least about 4.5 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours; or from about 0.5 hours to about 10 hours, from about 0.5 hours to about 9 hours, from about 0.5 hours to about 8 hours, from about 0.5 hours to about 7 hours, from about 0.5 hours to about 6 hours, from about 0.5 hours to about 5 hours, from about 0.5 hours to about 4.5 hours, from about 0.5 hours to about 4 hours, from about 0.5 hours to about 3.5 hours, from about 0.5 hours to about 3 hours, from about 0.5 hours to about 2.5 hours, from about 0.5 hours to about 2 hours, from about 0.5 hours to about 1.5 hours, from about 0.5 hours to about 1 hour, from
  • the catalyst may have an average particle size in a range of at least about 0.5 nm, at least about 0.8 nm, at least about 1 nm, at least about 2 nm, at least about 3 nm, at least about 4 nm, at least about 5 nm, at least about 6 nm, at least about 7 nm, at least about 8 nm, at least about 9 nm, at least about 10 nm, at least about 12 nm, at least about 14 nm, at least about 15 nm, at least about 16 nm, at least about 18 nm, at least about 20 nm, at least about 25 nm, at least about 30 nm, at least about 40 nm, at least about 50 nm; or from about 0.5 nm to about 50 nm, from about 0.5 nm to about 40 nm, from about 0.5 nm to about 30 nm, from about 0.5 nm to about 25
  • the average particle size of the catalyst is from about
  • step (c) 2 nm to about 5 nm after the pyrolysis of step (c).
  • the present disclosure provides for a catalyst, wherein the catalyst has an average particle size of about 1 nm to about 10 nm.
  • the present disclosure also provides for a catalyst, wherein the catalyst has an average particle size of about 2 nm to about 5 nm.
  • the present disclosure further provides for a method of preparing a catalyst, wherein step (c) produces a product having an average particle size of about 1 nm to about 10 nm.
  • step (c) produces a product having an average particle size of about 2 nm to about 5 nm.
  • the mixture from step (b) may be subjected to a thermal treatment step, for example pyrolysis, to remove the salts from the metal precursors, in order to leave behind metals and support.
  • a thermal treatment step for example pyrolysis
  • the thermal treatment may also be adjusted to further tune the physiochemical properties of the mixture remaining after thermal treatment.
  • the thermal treatment step (c) may be performed at a temperature range of at least about 200 °C, at least about 250 °C, at least about 275 °C, at least about 300 °C, at least about 325 °C, at least about 350 °C, at least about 375 °C, at least about 400 °C, at least about 450 °C, at least about 500 °C, at least about 550 °C, at least about 600 °C, at least about 650 °C, at least about 700 °C, at least about 750 °C, at least about 800 °C, at least about 900 °C, at least about 1000 °C; or from about 200 °C to about 1000 °C, from about 200 °C to about 900 °C, from about 200 °C to about 800 °C, from about 200 °C to about 750 °C, from about 200 °C to about 700 °C, from about 200 °C to about 650 °C, from about 200
  • the thermal treatment step (c) may also be performed for a duration of at least about 0.5 hours, at least about 1 hour, at least about 1.5 hours, at least about 2 hours, at least about 2.5 hours, at least about 3 hours, at least about 3.5 hours, at least about 4 hours, at least about 4.5 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours; or from about 0.5 hours to about 10 hours, from about 0.5 hours to about 9 hours, from about 0.5 hours to about 8 hours, from about 0.5 hours to about 7 hours, from about 0.5 hours to about 6 hours, from about 0.5 hours to about 5 hours, from about 0.5 hours to about 4.5 hours, from about 0.5 hours to about 4 hours, from about 0.5 hours to about 3.5 hours, from about 0.5 hours to about 3 hours, from about 0.5 hours to about 2.5 hours, from about 0.5 hours to about 2 hours, from about 0.5 hours to about 1.5 hours, from about 0.5 hours to about 1 hour, from about
  • the ramping rate of the temperature during the thermal treatment can also be used to tune the physiochemical properties of the catalyst.
  • the ramping rate may be in a range of at least about 0.1 °C/min, at least about 0.2 °C/min, at least about 0.25 °C/min, at least about 0.5 °C/min, at least about 0.75 °C/min, at least about 1.0 °C/min, at least about 1.25 °C/min, at least about 1.5 °C/min, at least about 1.75 °C/min, at least about 2.0 °C/min, at least about 2.25 °C/min, at least about 2.5 °C/min, at least about 2.75 °C/min, at least about 3.0 °C/min, at least about 3.5 °C/min, at least about 4.0 °C/min, at least about 4.5 °C/min, at least about 5.0 °C/min, at least about 6.0 °C/min; or from about 0.1 °C/
  • the present disclosure provides for a method of producing a catalyst, comprising pyrolyzing the ball-milled mixture of step (b) at a temperature of about 300 °C to about 600 °C for a duration of about 1 hour to about 5 hours to form a pyrolyzed product.
  • the present disclosure provides for a method of producing a catalyst, comprising pyrolyzing the ball-milled mixture of step (b) at a temperature of about 450 °C for a duration of about 2 hours to form a pyrolyzed product.
  • the present disclosure also discloses a method for preparing a supported catalyst, further comprising step (d) reducing the pyrolyzed product of step (c) to form the supported catalyst.
  • the presently disclosed method may also disclose a further step (d) to reduce the pyrolyzed product from step (c) to form the supported catalyst.
  • Reducing the pyrolyzed product from step (c) advantageously reduces the oxygen and/or oxide content of the catalyst which may accordingly increase the amount of active sites available for catalysis. Reducing the product may also surprisingly open up more activation sites that were previously unavailable to due the previously present oxide layers. Reduction may also further improve the porosity and surface area of the catalyst thus further improving its catalytic and OER efficiency.
  • the product of step (d) may be lower in oxygen and/or oxide compared as compared to before step (d) was applied.
  • the reduction step (d) may be performed in a reductive atmosphere, at a temperature of at least about 200 °C, at least about 250 °C, at least about 300 °C, at least about 350 °C, at least about 375 °C, at least about 400 °C, at least about 425 °C, at least about 450 °C, at least about 475 °C, at least about 500 °C, at least about 525 °C, at least about 550 °C, at least about 575 °C, at least about 600 °C, at least about 625 °C, at least about 650 °C, at least about 700 °C, at least about 750 °C, at least about 800 °C; or from about
  • Step (d) may be performed in a reductive atmosphere for a duration of at least about 0.1 hours, at least about 0.25 hours, at least about 0.5 hours, at least about 0.75 hours, at least about 1 hour, at least about 1.5 hours, at least about 2 hours, at least about 2.5 hours, at least about 3 hours, at least about 3.5 hours, at least about 4 hours, at least about 4.5 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, at least about 10 hours; or from about 0.1 hours to about 10 hours, from about 0.1 hours to about 9 hours, from about 0.1 hours to about 8 hours, from about 0.1 hours to about 7 hours, from about 0.1 hours to about 6 hours, from about 0.1 hours to about 5 hours, from about 0.1 hours to about 4.5 hours, from about 0.1 hours to about 4 hours, from about 0.1 hours to about 3.5 hours, from about 0.1 hours to about 3 hours, from about 0.1 hours to about 2.5 hours, from about 0.1 hours to about 2
  • step (d) is performed in a reductive atmosphere at a temperature of about 300 °C to about 600 °C, for a duration of about 0.5 hours to about 3 hours.
  • the reductive atmosphere comprises in Ar, Hi in a range of at least about 0.1 vol%, at least about 0.2 vol%, at least about 0.4 vol%, at least about 0.6 vol%, at least about 0.8 vol%, at least about 1.0 vol%, at least about 1.25 vol%, at least about 1.5 vol%, at least about 1.75 vol%, at least about 2.0 vol%, at least about 2.5 vol%, at least about 3.0 vol%, at least about 4.0 vol%, at least about 5.0 vol%, at least about 6.0 vol%, at least about 7.0 vol%, at least about 8.0 vol%, at least about 9.0 vol%, at least about 10.0 vol%, at least about 12.0 vol%, at least about 15.0 vol%, at least about 20.0 vol%, at least about 25.0 vol%, at least about 30.0 vol%, at least about 35.0 vol%, at least about 40.0 vol%; or from about 0.1 vol% to about 40.0 vol%, from about 0.1 vol% to about 35.0 vol%, from about
  • the present disclosure provides for a method of producing a supported catalyst, wherein the reductive atmosphere comprises from about 1 vol% to about 10 vol% Hj in Ar.
  • the present disclosure also provides for a method of producing a supported catalyst, wherein the oxygen and/or oxide content of the supported catalyst of step (d) is lower than the oxygen and/or oxide content of the pyrolyzed product of step (c).
  • the oxygen and/or oxide content of the supported catalyst of step (d) may be lower than the oxygen and/or oxide content of the pyrolyzed product of step (c) in a range of at least about 0.1 wt%, at least about 0.2 wt%, at least about 0.5 wt%, at least about 1 wt%, at least about 2 wt%, at least about 3 wt%, at least about 5 wt%, at least about 7 wt%, at least about 9 wt%, at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 30 wt%, at least about 40 wt%; or from about 0.1 wt% to about 40 wt%, from about 0.1 wt% to about 30 wt%, from about 0.1 wt% to about 20 wt%, from about 0.1 wt% to about 15 wt%, from about 0.1 wt% to about 10 wt
  • the presently disclosed method may be performed without using any solvents. This advantageously reduces the amount of liquid waste that needs to be treated or disposed of. By avoiding the use of solvents, the problem of treating such toxic liquid waste is also thus advantageously eliminated. Such a method is also advantageously more cost effective.
  • organometallic compounds of Ml, M2 and TM may comprise metal carbonyl compounds, metal ethylene complexes, metal-acetylacetonates, metal-acetates, metal cyanide compounds, metal-bis(acetylacetonate)s, and cyclopentadienyl metal compounds.
  • the present disclosure provides for a method, wherein the organometallic compound of Ml, M2 and TM is independently selected from the group consisting of metal carbonyl compounds, metal ethylene complexes, metal-acetylacetonates, metal-acetates, metal cyanide compounds, metal- bis(acetylacetonate)s, and cyclopentadienyl metal compounds.
  • the catalyst of the present invention may be used to advantageously drive a OER at a much higher efficiency as compared to other conventional catalysts.
  • the catalysts of the present invention may also advantageously require a much lower overpotential as compared to commercial catalysts to drive the OER, which results in lower energy costs, as well as increased safety, and increased energy efficiency.
  • the catalysts of the present invention may also exhibit unprecedented stability in acidic media. This is particularly pertinent as long-term operation of the catalysts in acidic conditions during hydrogen production and/or OER can result in degradation of the electrode, which thus requires the electrode to be regularly replaced. This results in increased operational costs. Instead, by providing catalysts that have unprecedented stability in acidic media, the electrodes formed from such catalysts are much more stable and thus require lower maintenance, resulting in advantageously lower operational costs in the long run.
  • the electrolytic production of hydrogen from water is also a concurrent process, comprising a Hydrogen Evolution Reaction (HER), as well as an Oxygen Evolution Reaction (OER).
  • HER Hydrogen Evolution Reaction
  • OER Oxygen Evolution Reaction
  • HER Hydrogen Evolution Reaction
  • OER Oxygen Evolution Reaction
  • (supported) catalysts are presently disclosed, for which they require a much lower overpotential as compared to commercial OER catalysts. Additionally, they also exhibit much better stability in acidic media as compared to commercial OER catalysts.
  • the catalysts of the present invention may also be advantageously used to produce hydrogen at much higher energy and cost efficiency as compared to commercial OER catalysts, with the concomitant release of oxygen in the process.
  • the present disclosure provides for a use of the catalyst disclosed herein for forming an electrode.
  • the present disclosure further provides for a use of the catalyst disclosed herein to produce oxygen.
  • the present disclosure also provides for a use of a supported catalyst disclosed herein to produce hydrogen.
  • the catalyst of the present invention may also be incorporated as an electrode into an electrochemical cell.
  • the catalyst of the present invention may also be incorporated as part of a system for producing hydrogen and/or oxygen.
  • the catalysts prepared by the methods described in the following examples exhibits enhanced intrinsic catalytic activity and stability during acidic water oxidation reactions, when compared to conventional pure IrO x catalysts.
  • the catalysts of the present invention may also provide up to 25 times higher catalytic activity while maintaining an enhanced catalytic stability.
  • the catalyst products may also be compatible with conventional processes for fabricating Polymer Electrolyte Membrane (PEM) water electrolyzers. Given the much lower loading of iridium and ruthenium, the catalysts and the methods for making such catalysts as disclosed in the present invention are expected to become a viable choice when fabricating PEM water electrolyzers.
  • PEM Polymer Electrolyte Membrane
  • a mixture of iridium-acetylacetonate (25.47 mg), ruthenium-acetylacetonate (118.26 mg), cobalt - acetylacetonate (Co(acac)j, 181.15 mg) and WO3 support (400 mg) were added into a Nylon jar.
  • the mixture comprised iridium, ruthenium and cobalt metals in a weight ratio of about 1:3:3 (Ir:Ru:Co), whereas the weight of WO3 added was 10 times the total weight of the metals (M1+M2; Ir+Ru) present.
  • the above mixture comprises Co metal (30 mg), Ir metal (10 mg), Ru metal (30 mg) and WO3 (400 mg) and the molar ratio of Ir:Ru:Co:W in the mixture is about 1 : 6 : 10 : 34.6.
  • the composition of the metals in the final mixture can be accordingly tuned by adjusting the ratio of the salts added to the mixture prior to ball-milling. Zirconia milling beads were further added to the mixture in the Nylon jar, after which the mixture was subjected to ball-milling with a rotating speed of 300 rpm for 3 hours.
  • Example la The ball-milled mixture from Example la was subjected to pyrolysis in air at 450 °C (25 °C to 450 °C at a ramping rate of 2.0 °C/min, maintaining at 450 °C for 2 h) in a muffle furnace (Carbolite, UK). After cooling down to room temperature, the product was collected and named as Ii iRmCo;,- WO 3 .
  • Example lb A portion of the product from Example lb was reduced in a reductive atmosphere at either 450 °C or 550 °C in 5 % FE/Ar for 1 h in a tubular furnace (Carbolite, UK) to obtain either hjRusCos- WO3-R-450 °C or IriRu 3 Co 3 -WO3-R-550 °C.
  • ICP Inductively Coupled Plasma
  • Fig. 2a shows the XRD patterns of the catalysts prepared from Examples lb and 1c, with some other catalysts as reference.
  • most of the diffraction signals originate from the WO3 support.
  • Example 1c hjRu3Co3-WO3-R-450 °C
  • a very weak diffraction peak appears at -45°, which can be assigned to the (101) diffraction of metallic Ru.
  • the weak diffraction intensity of noble metal related compounds again, agrees well with the low content of noble metals in the samples.
  • Fig. 2b showing the SEM image of the product from Example 1c (hjRu3Co3-WO3-R-450 °C), indicates aggregated nanoparticles with size of several hundred nanometers. No obvious structure segregation can be identified, suggesting that Ii'iRinCo? has been uniformly loaded on the WO3 support.
  • TEM images show that average particle size was in the range of 2-5 nm for the product from Example lb ( hi RinGn-WOd after the pyrolysis step. Moreover, the average size of particles did not change after further thermal treatment in reductive atmosphere at 450 °C in H2(5 %)/Ar for 1 h (Fig. 4c and 4d). This could suggest that the catalyst after pyrolysis comprises substantially either metals or their oxides thereof. The reduction of the catalyst without changing the average size could also indicate that the catalysts have become more porous after the reduction process.
  • the chemical states of samples were further examined by X-ray photoelectron spectroscopy (XPS) and shown in Figs. 3a to 3f.
  • XPS X-ray photoelectron spectroscopy
  • Fig. 3 shows the O Is, Ir 4f, Ru 3d, Co 2p and W 4f of the products from Examples lb and 1c (IriRusCos-WOs, IriRu3Co3-WO3-R-450 °C and IriRu3Co3-WO3-R-550 °C).
  • thermal treatment in reductive atmosphere was able to reduce the content of oxygen in samples.
  • the oxygen content decreased from about 52 % to 49% after the product from Example lb was reduced at 450 °C and decreased from about 52 % to 43 % after reduction at 550 °C.
  • Figs. 5a to 5d show the results of the Linear Sweep Voltammetry experiments, wherein the curves were recorded at a scan rate of 5 mV s -1 normalized to geometric area.
  • Fig. 5a compares the LSV curves, among which hjRusCos-WCL-R (produced at either reduction at 450 °C or 550 °C) displayed the best OER performance in the acidic medium with the lowest overpotential to reach 10 mA cm 2 catalytic current density (260 mV). This was in comparison to commercial IrO x catalyst requiring an overpotential of 290 mV.
  • the Tafel slope of hi RinC WCh-R (both 450 °C and 550 °C) were about 46 mV/dec, much lower than that of commercial IrO x (66 mV/dec).
  • the Ii'i RusCos-WOs-R exhibited much higher intrinsic water oxidation activity.
  • the mass- normalized current density of hi RinG)?- WO3-R as shown in Fig. 5c was about 250 mA/mgNobie-Metai, which is 25 times higher than that of the commercial IrO x catalyst.
  • the stability of the catalyst hjRu3Co3-WO3-R-450 °C from Example 1c was evaluated using chronopotentiometry experiments.
  • the mass loading of Ir+Ru for hjRu3Co3-WO3-R-450 °C and IrO x catalyst were 100 pg and 225 pg cm“ 2 gm , respectively.
  • the experiment was recorded in 0.5 M H2SO4 electrolyte at a current density of 10 mA cm“ 2 gm .
  • hjRu3Co3-WO3-R-450 °C is very stable in acidic conditions, which is likely due to the strong interaction between the metals ( Ii'iRinCo?) and the WO3 support.
  • the present invention relates to catalysts, in particular, catalysts for oxygen evolution reactions.
  • the catalysts of the present invention require a significantly lower overpotential to drive the OER as compared to currently known catalysts.
  • the catalysts of the present invention are also advantageously compatible with commercial fabrication processes of PEM water electrolyzers and other electrochemical devices, and hence may be easily taken up without any difficulty.
  • the catalysts of the present invention may thus also be advantageously used in producing hydrogen.
  • the present disclosure also refers to a method of producing such catalysts.
  • the method of the present invention may be easily scaled for large-scale synthesis. Current industrial infrastructure can also be easily modified to fit the process requirements.
  • the method of the present invention also does not use any solvents, and thus greatly reduces the amount of liquid waste that needs to be treated or disposed of, reducing environmental waste produced.
  • the method of the present invention accordingly also does not product liquid wastes of metals that are often toxic and/or environmentally hazardous, hence further reducing its environmental impact.
  • the method of the present invention also utilizes precursors that are advantageously easier to handle as compared to the metallic elements, and thus the method is easier to take up in industry. Thus this invention is capable of industrial applicability.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Electrochemistry (AREA)
  • Metallurgy (AREA)
  • Inorganic Chemistry (AREA)
  • Catalysts (AREA)

Abstract

La présente divulgation concerne un catalyseur supporté comprenant M1, M2, TM et S1, dans lequel : M1 et M2 représentent des métaux indépendamment choisis dans le groupe constitué par Ru, Pd, Ir, Pt, Au, Os, Re, Rh, Ag, Mo, Tc et Nb ; TM représente un métal de transition ; S1 représente un support ; le rapport pondéral M1/M2/TM se situe dans la plage d'environ 1/2-10/2-10 ; le rapport pondéral (M1 + M2)/S1 se situe dans la plage d'environ 1/5-20 ; et M1, M2 et TM sont différents. La présente divulgation concerne également un procédé de préparation d'un catalyseur supporté, le procédé comprenant les étapes consistant à : (a) préparer un mélange comprenant un composé organométallique de M1, un composé organométallique de M2, un composé organométallique de TM, et S1, dans lequel : M1 et M2 représentent des métaux indépendamment choisis dans le groupe constitué par Ru, Pd, Ir, Pt, Au, Os, Re, Rh, Ag, Mo, Tc et Nb ; TM représente un métal de transition ; S1 représente un support ; le rapport pondéral M1/M2/TM se situe dans la plage d'environ 1/2-10/2-10 ; le rapport pondéral (M1 + M2)/S1 se situe dans la plage d'environ 1 /5-20 ; et M1, M2 et TM sont différents ; (b) broyer par broyage à billes le mélange de l'étape (a) à une vitesse de rotation d'environ 200 tours/minute à environ 900 tours/minute pendant une durée d'environ 1 heure à environ 5 heures pour former un mélange de broyage à billes, et (c) pyrolyse le mélange de broyage à billes de l'étape (b) à une température d'environ 300 °C à environ 600 °C pendant une durée d'environ 1 heure à environ 5 heures pour former un produit pyrolysé. La présente divulgation concerne également l'utilisation d'un catalyseur supporté divulgué ici pour produire de l'hydrogène.
PCT/SG2022/050783 2021-10-29 2022-10-28 Catalyseurs Ceased WO2023075704A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SG10202112087X 2021-10-29
SG10202112087X 2021-10-29

Publications (2)

Publication Number Publication Date
WO2023075704A2 true WO2023075704A2 (fr) 2023-05-04
WO2023075704A3 WO2023075704A3 (fr) 2023-08-17

Family

ID=86160657

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SG2022/050783 Ceased WO2023075704A2 (fr) 2021-10-29 2022-10-28 Catalyseurs

Country Status (1)

Country Link
WO (1) WO2023075704A2 (fr)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070160899A1 (en) * 2006-01-10 2007-07-12 Cabot Corporation Alloy catalyst compositions and processes for making and using same
CN103285880B (zh) * 2013-05-28 2015-09-16 浙江科技学院 一种质子交换膜燃料电池催化剂的制备方法
KR101901223B1 (ko) * 2017-11-07 2018-09-21 광주과학기술원 자동차용 연료전지를 위한 다기능성 비백금 담지 촉매 및 그 제조 방법
CN111048793B (zh) * 2019-12-27 2021-06-22 苏州擎动动力科技有限公司 铂基八面体催化剂的制备方法
CN113555566A (zh) * 2021-07-19 2021-10-26 苏州立昂新材料有限公司 铂碳催化剂及其制备方法

Also Published As

Publication number Publication date
WO2023075704A3 (fr) 2023-08-17

Similar Documents

Publication Publication Date Title
Lu et al. Electrocatalysis of single-atom sites: impacts of atomic coordination
Pei et al. Glycerol oxidation-assisted electrochemical CO 2 reduction for the dual production of formate
Zhao et al. Surface reconstruction of La0. 8Sr0. 2Co0. 8Fe0. 2O3− δ for superimposed OER performance
Zhao et al. Size-controlled hydrothermal synthesis and high electrocatalytic performance of CoS 2 nanocatalysts as non-precious metal cathode materials for fuel cells
Seo et al. Size-dependent activity trends combined with in situ X-ray absorption spectroscopy reveal insights into cobalt oxide/carbon nanotube-catalyzed bifunctional oxygen electrocatalysis
Long et al. Synthesis and characterization of Pt–Pd alloy and core-shell bimetallic nanoparticles for direct methanol fuel cells (DMFCs): Enhanced electrocatalytic properties of well-shaped core-shell morphologies and nanostructures
CN108855166B (zh) 一种负载型催化剂及其制备方法、应用
de Oliveira et al. NiOx-Pt/C nanocomposites: Highly active electrocatalysts for the electrochemical oxidation of hydrazine
US20100233070A1 (en) CARBON-SUPPORTED CoSe2 NANOPARTICLES FOR OXYGEN REDUCTION AND HYDROGEN EVOLUTION IN ACIDIC ENVIRONMENTS
AU2012271494B2 (en) Non-PGM cathode catalysts for fuel cell application derived from heat treated heteroatomic amines precursors
Ma et al. Synthesis of highly active and stable spinel‐type oxygen evolution electrocatalysts by a rapid inorganic self‐templating method
Wang et al. Selective electro-reforming of waste polyethylene terephthalate-derived ethylene glycol into C 2 chemicals with long-term stability
EP2187469B1 (fr) Couche catalytique d'électrode, ensemble électrode à membrane et pile à combustible
WO2020167257A1 (fr) Catalyseur composite à faible coût et à faible teneur en platine pour piles à combustible à membrane échangeuse de protons à basse température
JP6086981B2 (ja) カルベンダジム系触媒作用物質
Zhang et al. Glycerol electrooxidation on highly active Pd supported carbide/C aerogel composites catalysts
Wu et al. Exploring the role of cobalt in promoting the electroactivity of amorphous Ni-B nanoparticles toward methanol oxidation
Tuo et al. The facile synthesis of core–shell PtCu nanoparticles with superior electrocatalytic activity and stability in the hydrogen evolution reaction
Carrillo-Rodríguez et al. Evaluation of the novel PdCeO2-NR electrocatalyst supported on N-doped graphene for the oxygen reduction reaction and its use in a microbial fuel cell
Sweeney et al. Impacts of oxygen vacancies on the electrocatalytic activity of AuTiO2 nanocomposites towards oxygen reduction
Lenarda et al. Nanostructured carbon supported Pd-ceria as anode catalysts for anion exchange membrane fuel cells fed with polyalcohols
Roh et al. Preparation of carbon-supported Pt–Ru core-shell nanoparticles using carbonized polydopamine and ozone for a CO tolerant electrocatalyst
Meku et al. Concentration gradient Pd-Ir-Ni/C electrocatalyst with enhanced activity and methanol tolerance for oxygen reduction reaction in acidic medium
Shi et al. Boosting electrocatalytic performance and durability of Pt nanoparticles by conductive MO2− x (M= Ti, Zr) supports
Khater et al. Reduced graphene oxide-supported palladium oxide-MOx for improving the performance of air-cathode microbial fuel cells: influence of the Sn, Ce, Zn, and Fe precursors

Legal Events

Date Code Title Description
NENP Non-entry into the national phase

Ref country code: DE

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22887827

Country of ref document: EP

Kind code of ref document: A2

122 Ep: pct application non-entry in european phase

Ref document number: 22887827

Country of ref document: EP

Kind code of ref document: A2