US3843491A - Process for the preparation of silver base catalyst - Google Patents
Process for the preparation of silver base catalyst Download PDFInfo
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- US3843491A US3843491A US00319060A US31906072A US3843491A US 3843491 A US3843491 A US 3843491A US 00319060 A US00319060 A US 00319060A US 31906072 A US31906072 A US 31906072A US 3843491 A US3843491 A US 3843491A
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- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 title claims abstract description 55
- 229910052709 silver Inorganic materials 0.000 title claims abstract description 53
- 239000004332 silver Substances 0.000 title claims abstract description 53
- 238000000034 method Methods 0.000 title claims abstract description 27
- 239000003054 catalyst Substances 0.000 title claims abstract description 19
- 238000002360 preparation method Methods 0.000 title claims abstract description 13
- 238000004070 electrodeposition Methods 0.000 claims abstract description 10
- 229940100890 silver compound Drugs 0.000 claims abstract description 9
- 150000003379 silver compounds Chemical class 0.000 claims abstract description 9
- 150000002500 ions Chemical class 0.000 claims abstract description 7
- 238000000151 deposition Methods 0.000 claims abstract description 5
- 230000000536 complexating effect Effects 0.000 claims abstract description 3
- 238000005868 electrolysis reaction Methods 0.000 description 10
- 239000000243 solution Substances 0.000 description 9
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 6
- 239000005977 Ethylene Substances 0.000 description 6
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical class [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 5
- 239000008151 electrolyte solution Substances 0.000 description 4
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000001680 brushing effect Effects 0.000 description 3
- 239000001768 carboxy methyl cellulose Substances 0.000 description 3
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 3
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 150000003378 silver Chemical class 0.000 description 3
- 229910001961 silver nitrate Inorganic materials 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- 101710134784 Agnoprotein Proteins 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 150000007514 bases Chemical class 0.000 description 2
- 229910021538 borax Inorganic materials 0.000 description 2
- 239000000084 colloidal system Substances 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000001012 protector Effects 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000004328 sodium tetraborate Substances 0.000 description 2
- 235000010339 sodium tetraborate Nutrition 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 1
- JKNZUZCGFROMAZ-UHFFFAOYSA-L [Ag+2].[O-]S([O-])(=O)=O Chemical compound [Ag+2].[O-]S([O-])(=O)=O JKNZUZCGFROMAZ-UHFFFAOYSA-L 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- ZOMNIUBKTOKEHS-UHFFFAOYSA-L dimercury dichloride Chemical class Cl[Hg][Hg]Cl ZOMNIUBKTOKEHS-UHFFFAOYSA-L 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 239000008246 gaseous mixture Substances 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000010297 mechanical methods and process Methods 0.000 description 1
- 230000003340 mental effect Effects 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 150000003891 oxalate salts Chemical class 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000002572 peristaltic effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000005201 scrubbing Methods 0.000 description 1
- CQLFBEKRDQMJLZ-UHFFFAOYSA-M silver acetate Chemical compound [Ag+].CC([O-])=O CQLFBEKRDQMJLZ-UHFFFAOYSA-M 0.000 description 1
- 229940071536 silver acetate Drugs 0.000 description 1
- -1 silver halides Chemical class 0.000 description 1
- XNGYKPINNDWGGF-UHFFFAOYSA-L silver oxalate Chemical compound [Ag+].[Ag+].[O-]C(=O)C([O-])=O XNGYKPINNDWGGF-UHFFFAOYSA-L 0.000 description 1
- UKHWJBVVWVYFEY-UHFFFAOYSA-M silver;hydroxide Chemical class [OH-].[Ag+] UKHWJBVVWVYFEY-UHFFFAOYSA-M 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D301/00—Preparation of oxiranes
- C07D301/02—Synthesis of the oxirane ring
- C07D301/03—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds
- C07D301/04—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with air or molecular oxygen
- C07D301/08—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with air or molecular oxygen in the gaseous phase
- C07D301/10—Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with air or molecular oxygen in the gaseous phase with catalysts containing silver or gold
-
- 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
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/48—Silver or gold
- B01J23/50—Silver
-
- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/34—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation
- B01J37/348—Electrochemical processes, e.g. electrochemical deposition or anodisation
-
- 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
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/134—Reduction of greenhouse gas [GHG] emissions by avoiding CO2, e.g. using hydrogen
Definitions
- the present invention refers to an improved process for the preparation of silver base catalysts which are useful in the synthesis of ethylene oxide.
- the present invention refers to a process for the electrochemical preparation of silver base catalysts.
- silver production might be possible with high yields and in a reproducible way when using systems of electrochemic deposition of such metal; but it is also known that the electrolysis of silver solutions gives rise to a metal having a compact shape or, in any case, high particle sizes that render them unusable in the industrial process for the production of ethylene oxide by ethylene oxidation.
- the detaching of stored silver from the cathode may be eifected by mechanical methods or by ultra-sonic vibrations.
- Helpful uses can be made of the following mechanical techniques: employment of brushes sliding on the cathode and vice versa, employment of a vibrating or oscillating cathode, jets of liquid under pressure onto the cathode, violent stirring of the electrolytic solution.
- the silver compounds usefully employable as electrolytic solution in the process of our invention can be selected from salts such as silver nitrates, silver sulphate, silver acetate, silver halides, silver oxalate, or complexed basic compounds such as ammoniacal silver hydroxides.
- the silver salts be complexed with ammonia or with fluoboric ions.
- Electrolysis is generally carried out in the presence of protector colloids such as cellulose derivatives, for instance carboxymethylcellulose.
- protector colloids such as cellulose derivatives, for instance carboxymethylcellulose.
- the electrolytic operation is generally performed at low temperatures, between 10 and 50 C.
- the current density may vary over a large range: however use is preferably made of values ranging between 2 mampers/cm. and 50 mampers/cmfi.
- the following working examples illustrate the. invention but are not limitative thereof.
- EXAMPLE 1 100 g. of AgNo 750 g. of borax (N B O 1O H 0), 400 g. of NaOH were dissolved in distilled water and diluted upto a 10011 volume. Thereto were added 600 cc. of aqueous ammonia solution (28 Be.) and 10 g. of carboxymethylcellulose (before solubilized on another side). 3.5 liters of the aforesaid solution were poured into the electrolytic all shown in 'FIG. 1 with an anode consisting of compact graphite 1 and a cathode consisting of a silver plate 2.
- the cell was provided with the system of mechanical removal of the deposited silver consistuted by two plastic brushes 3,3 whose speed of rotation may range over large limits by means of a geared motor 4.
- the brushes were arranged so as to lap the cathode surface.
- the electrolysis was carried out at constant current by means of an amperostat.
- a reference electrode saturated calomel contacted to cathode to measure the electrode potential.
- the electrodeposition was carried out under the follow: ing conditions:
- the electric energy consumption was about 0.7 kwh. per kg. of produced silver, the yield was close to
- the produced silver having average sizes of 800 A., was washed with water made free from ions, dried in an oven at 80 C. and then deposited, by suitable technics, on a ceramic carrier in order to carry out a test of catalyst activity.
- the catalyst constituted by' carrier and silver in an amount of 15%, was introduced into a 2.4 cm. pipe, equipped with "an external jacket allowing the thermostating liquidto circulate.
- the catalytic bed heighflwas aboutlm.v
- a gaseous mixture was fed into the reactor at atmospheric pressure having the following composition: 5% ethylene, 6.5% C0 5% 0 83.5% N
- the feed flow was 210 Nl/h. and the contact time was about 4.6 sec.
- the energy consumption was about 3 kwh. per kg. of produced silver.
- EXAMPLE 3 An electrolysis was carried out on the solution of Example 1 by using ultra-sonic vibrations for detaching silver.
- the experimental conditions were the following ones:
- Anode Compact graphite Anode surface 100 cmfl.
- the sound head of ultra-sonic vibrations was electrically connected to the cathode so as to avoid possible corrosion processes.
- the silver obtained under the aforesaid experimental conditions had sizes of about 800 A. and gave rise to conversion and selectivity values, in the ethylene-ethylene oxide reaction, of 25% and 78%.
- EXAMPLE 4 This example relates to one of the possible industrial processes for preparing silver base catalyst by an electrodeposition from silver nitrate solutions with continuous current and continuous detaching of the electrodepositated material in an electrolytic cell of bipolar type.
- a process for the preparation of silver useful as a catalyst by silver electrochemical deposition comprising: complexing a silver compound with a member selected from the group consisting of ammonic and fluoboric ions, electrolytically depositing the silver compound on a cathode, and concurrently removing the deposited silver from said cathode whereby the removed silver has a size of less than 1500- A.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Electrochemistry (AREA)
- Health & Medical Sciences (AREA)
- Plasma & Fusion (AREA)
- Toxicology (AREA)
- Electrolytic Production Of Metals (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Catalysts (AREA)
- Epoxy Compounds (AREA)
Abstract
1. A PROCESS FOR THE PREPARATION OF SILVER USEFUL AS A CATALYST BY SILVER ELECTROCHEMICAL DEPOSITION COMPRISING: COMPLEXING A SILVER COMPOUND WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF AMMONIC AND FLUOBORIC IONS, ELECTROLYTICALLY DEPOSITING THE SILVER COMPOUND ON A CATHODE, AND CONCURRENTLY REMOVING THE DEPOSITED SILVER FROM SAID CATHODE WHEREBY THE REMOVED SILVER HAS A SIZE OF LESS THAN 1500 A.
Description
Oct. 22, 1974 M. PIRO ETAL 3,843,491
PRocEss FOR THE PREPARATION OF SILVER msn cxum's'r I Filed Dec. 27,)972
US. Cl. 204-10 14 Claims ABSTRACT OF THE DISCLOSURE A process is described whereby a catalyst grade of finely divided silver, having a particle size in the range from 300 A. to 1500 A., is produced through the electrolytic deposition of silver on a cathode and the mechanical removal of the silver from the cathode as it is formed, either by subjecting the cathode to ultrasonic vibrations or to a scrubbing action by means of brushes or jets of liquid under pressure or violent stirring.
The present invention refers to an improved process for the preparation of silver base catalysts which are useful in the synthesis of ethylene oxide.
More particularly the present invention refers to a process for the electrochemical preparation of silver base catalysts.
' It is known that there are many processes for preparing silver base catalysts for the preparation of ethylene xide; and it is also known that the silver structure and the working conditions which allow it to be obtained have a remarkable importance in obtaining high activities and selectivities. The chemical methods, previously proposed, substantially consist of the decomposition of silver salts or compounds in order to obtain silver in a finely subdivided state.
Such methods have the principal drawback of poor reproducibility and the inevitable silver losses which occur during the treatments: this fact imposes expensive recovery processes.
On the other hand silver production might be possible with high yields and in a reproducible way when using systems of electrochemic deposition of such metal; but it is also known that the electrolysis of silver solutions gives rise to a metal having a compact shape or, in any case, high particle sizes that render them unusable in the industrial process for the production of ethylene oxide by ethylene oxidation.
It has now been found that it is possible to produce, electrochemically, silver catalysts whose particles have sizes lower than 1500 A. and preferably between 300 'A. and 1500 A. which, when used in the synthesis of ethylene oxide by ethylene oxidation, give high activities and selectivities.
Moreover it has been found that it is possible to produce silver, which is useful for the synthesis of ethylene oxide, whose crystalline aggregates show sizes ranging between 300 A. and 1500 A. by an electrolysis of silver compounds, wherein silver is removed from the cathode as it is formed.
The detaching of stored silver from the cathode may be eifected by mechanical methods or by ultra-sonic vibrations.
Helpful uses can be made of the following mechanical techniques: employment of brushes sliding on the cathode and vice versa, employment of a vibrating or oscillating cathode, jets of liquid under pressure onto the cathode, violent stirring of the electrolytic solution.
3,843,491 Patented Oct. 22, 1974 The silver compounds usefully employable as electrolytic solution in the process of our invention can be selected from salts such as silver nitrates, silver sulphate, silver acetate, silver halides, silver oxalate, or complexed basic compounds such as ammoniacal silver hydroxides.
Furthermore it is preferable that the silver salts be complexed with ammonia or with fluoboric ions.
It is also advantageous to use a buffer keeping the solution pH at a value ranging from 10 to 14.
Electrolysis is generally carried out in the presence of protector colloids such as cellulose derivatives, for instance carboxymethylcellulose.
The electrolytic operation is generally performed at low temperatures, between 10 and 50 C. The current density may vary over a large range: however use is preferably made of values ranging between 2 mampers/cm. and 50 mampers/cmfi. The following working examples illustrate the. invention but are not limitative thereof.
EXAMPLE 1 100 g. of AgNo 750 g. of borax (N B O 1O H 0), 400 g. of NaOH were dissolved in distilled water and diluted upto a 10011 volume. Thereto were added 600 cc. of aqueous ammonia solution (28 Be.) and 10 g. of carboxymethylcellulose (before solubilized on another side). 3.5 liters of the aforesaid solution were poured into the electrolytic all shown in 'FIG. 1 with an anode consisting of compact graphite 1 and a cathode consisting of a silver plate 2.
The cell was provided with the system of mechanical removal of the deposited silver consistuted by two plastic brushes 3,3 whose speed of rotation may range over large limits by means of a geared motor 4.
The brushes were arranged so as to lap the cathode surface. I
A peristaltic pump, outside the cell, took in.the electrolytic solution, made it pass through a heat exchanger and sent it again into the cell. s, s I
During electrolysis the silver titre was kept constant by means of periodic additions of silver nitrate complexed with ammonia in excess. v s
The electrolysis was carried out at constant current by means of an amperostat. A reference electrode (saturated calomel) contacted to cathode to measure the electrode potential. v
The electrodeposition was carried out under the follow: ing conditions:
Temperature 20 C. Cathode surface 80 cm.'*. Anode surface 80 cm.
= Current density 6 ma./cm.
Distance between the electrodes 3 cm. Cathode potential 1000 mv. on S.C.E. Brushing speed rotation's'per minute. Tension applied to cell 3 v. l
The electric energy consumption was about 0.7 kwh. per kg. of produced silver, the yield was close to The produced silver, having average sizes of 800 A., was washed with water made free from ions, dried in an oven at 80 C. and then deposited, by suitable technics, on a ceramic carrier in order to carry out a test of catalyst activity. The catalyst, constituted by' carrier and silver in an amount of 15%, was introduced into a 2.4 cm. pipe, equipped with "an external jacket allowing the thermostating liquidto circulate. The catalytic bed heighflwas aboutlm.v A gaseous mixture was fed into the reactor at atmospheric pressure having the following composition: 5% ethylene, 6.5% C0 5% 0 83.5% N The feed flow was 210 Nl/h. and the contact time was about 4.6 sec.
: At 200 C. we obtained conversionand selectivity values of 30 and 80% respectively.
EXAJMPLE 2 An electrolysis was performed on the solution of Example 1 by working according to the following experi mental conditions:
Temperature 18 C.
Apparent current density 70 ma./crn.
Cathode potential -1000 mv. on S.C.E.
Cathode Silver net having 1 x 1 mm. meshes.
Brushing speed 200 rotations/ minute.
Tension 12v.
The energy consumption was about 3 kwh. per kg. of produced silver.
The silver produced, deposited on a ceramic material, was put in a reactor under the conditions of Example 1. At 220 C. we obtained, in the conversion reaction of ethylene to ethylene oxide, conversion and selectivity values of 20 and 80% respectively. The obtained silver had crystal sizes of 700 A.
EXAMPLE 3 An electrolysis was carried out on the solution of Example 1 by using ultra-sonic vibrations for detaching silver. The experimental conditions were the following ones:
Position of the sound head Close to cathode. Temperature 15 C.
Cathode Ag plate.
Cathode surface 50 crnfi.
Anode Compact graphite. Anode surface 100 cmfl.
Current density 50 ma./cm. Tension 10 v.
Cathode potential -1300 mv.
The sound head of ultra-sonic vibrations was electrically connected to the cathode so as to avoid possible corrosion processes.
The silver obtained under the aforesaid experimental conditions had sizes of about 800 A. and gave rise to conversion and selectivity values, in the ethylene-ethylene oxide reaction, of 25% and 78%.
EXAMPLE 4 This example relates to one of the possible industrial processes for preparing silver base catalyst by an electrodeposition from silver nitrate solutions with continuous current and continuous detaching of the electrodepositated material in an electrolytic cell of bipolar type.
Use was made of an electrolyte having the following composition:
AgNo 0.5+10 g/C Borax 5 +20 g/ C Carboxymethylcellulose 0.04+0.5 g/ C NH 5+100 g/C NaOH 3+100 g/C .7 from electrolyte and then again pumped into the elec trolytic cell.
What we claimis:
1. A process for the preparation of silver useful as a catalyst by silver electrochemical deposition comprising: complexing a silver compound with a member selected from the group consisting of ammonic and fluoboric ions, electrolytically depositing the silver compound on a cathode, and concurrently removing the deposited silver from said cathode whereby the removed silver has a size of less than 1500- A.
2. The process for the preparation of silver useful as catalyst by means of electrochemical deposition according to claim 1 characterized in that the silver removed from cathode is carried out by brushing cathode.
3. The process for the preparation of silver useful as catalyst by means of electrochemical deposition according to claim 1 characterized in that the removal of the silver from the cathode is carried out by employing ultra-Sonics.
4. The process for the preparation of silver useful as catalyst by means of electrochemical deposition according to claim 1 characterized in that the removal of silver from the cathode is carried out by spouts of liquid under pressure.
5. The process for the preparation of silver useful as catalyst by means of electrochemical deposition according to claim 1 characterized in that the silver is removed from the cathode by subjecting the electrolytic solution to a strong stirring.
6. The process for the preparation of silver useful as catalyst by means of electrochemical deposition according to claim 1 characterized in that the silver compound subjected to electrolysis in solution is a salt selected from the group consisting of nitrates, sulphates, acetates, halides, oxalates and basic compounds as silver ammoniacal hydroxides.
7. The process according to claim 6 characterized in that the silver salts are complexed with ammonic ions.
8. The process according to claim 6 characterized in that a buffer is included in the solution which maintains the solution pH at a value of about between 10 and 14.
9. The process according to claim 6 characterized in that the electrolysis is carried out in presence of protector colloids selected from the cellular derivatives.
10. The process according to claim 1 characterized in that the electrolysis is carried out at temperatures ranging between 10 and 50 C.
11. The process according to claim 10 characterized in that the current density ranges from 2 m. amperes/cm. to m. amperes/cmF.
12. The process according to claim 1 wherein said silver catalyst has a size of about between 300 A. and 1500 A.
13. The process according to claim 12 wherein said silver catalyst is used in the production of ethylene oxide from ethylene and oxygen or air.
14. The process according to claim 6 characterized in that the silver salts are complexed with fiuoboric ions.
References Cited 10/1971 Adamson et al 204 1o T. TUFARIELLO, Primary Examiner US. Cl. X.R. 204-109
Claims (1)
1. A PROCESS FOR THE PREPARATION OF SILVER USEFUL AS A CATALYST BY SILVER ELECTROCHEMICAL DEPOSITION COMPRISING: COMPLEXING A SILVER COMPOUND WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF AMMONIC AND FLUOBORIC IONS, ELECTROLYTICALLY DEPOSITING THE SILVER COMPOUND ON A CATHODE, AND CONCURRENTLY REMOVING THE DEPOSITED SILVER FROM SAID CATHODE WHEREBY THE REMOVED SILVER HAS A SIZE OF LESS THAN 1500 A.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT33010/71A IT944424B (en) | 1971-12-28 | 1971-12-28 | PROCEDURE FOR THE PREPARATION OF SILVER-BASED CATALYSTS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3843491A true US3843491A (en) | 1974-10-22 |
Family
ID=11236250
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US00319060A Expired - Lifetime US3843491A (en) | 1971-12-28 | 1972-12-27 | Process for the preparation of silver base catalyst |
Country Status (23)
| Country | Link |
|---|---|
| US (1) | US3843491A (en) |
| JP (1) | JPS5511895B2 (en) |
| AR (1) | AR196221A1 (en) |
| AT (1) | AT333702B (en) |
| AU (1) | AU476492B2 (en) |
| BE (1) | BE792890A (en) |
| BR (1) | BR7208712D0 (en) |
| CA (1) | CA1028276A (en) |
| CH (1) | CH556915A (en) |
| CS (1) | CS162787B2 (en) |
| DD (1) | DD103269A5 (en) |
| DE (1) | DE2263883C3 (en) |
| ES (1) | ES410294A1 (en) |
| FR (1) | FR2186541B1 (en) |
| GB (1) | GB1400758A (en) |
| HU (1) | HU165610B (en) |
| IT (1) | IT944424B (en) |
| LU (1) | LU66759A1 (en) |
| NL (1) | NL7217691A (en) |
| RO (1) | RO58869A (en) |
| TR (1) | TR17434A (en) |
| YU (1) | YU36103B (en) |
| ZA (1) | ZA727973B (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4302319A (en) * | 1978-08-16 | 1981-11-24 | Katsyguri Ijybi | Continuous electrolytic treatment of circulating washings in the plating process and an apparatus therefor |
| US5413987A (en) * | 1994-01-24 | 1995-05-09 | Midwest Research Institute | Preparation of superconductor precursor powders |
| US5462647A (en) * | 1994-09-09 | 1995-10-31 | Midwest Research Institute | Preparation of lead-zirconium-titanium film and powder by electrodeposition |
| US5785837A (en) * | 1996-01-02 | 1998-07-28 | Midwest Research Institute | Preparation of transparent conductors ferroelectric memory materials and ferrites |
| WO2001051685A3 (en) * | 2000-01-10 | 2002-09-19 | Michael John Sole | Removal of metals from solution |
| CN101579889B (en) * | 2009-06-05 | 2010-10-13 | 黎永健 | Ceramic powder feeding device and feeding method thereof |
| US20130075251A1 (en) * | 2011-09-23 | 2013-03-28 | Bayer Intellectual Property Gmbh | Oxygen-consuming electrode and process for the production thereof |
| US20130075249A1 (en) * | 2011-09-23 | 2013-03-28 | Bayer Intellectual Property Gmbh | Oxygen-consuming electrode and process for production thereof |
| CN103060854A (en) * | 2013-01-11 | 2013-04-24 | 东南大学 | Method for electrochemical synthesis of colloidal silver solution |
| CN104492428A (en) * | 2014-11-28 | 2015-04-08 | 东莞市青麦田数码科技有限公司 | Silver or bismuth doped zirconium dioxide nanotube as well as preparation method and application thereof |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2715856C2 (en) * | 1977-04-06 | 1984-04-12 | Duval Corp., 77002 Houston, Tex. | Method and device for the continuous extraction of metals, in particular copper, in the form of a particulate crystalline material |
| NL8503090A (en) * | 1985-11-11 | 1987-06-01 | Harshaw Chemie Bv | METHOD FOR PREPARING MOUNTED CATALYST SYSTEMS |
| JPH04131393A (en) * | 1990-09-21 | 1992-05-06 | Power Reactor & Nuclear Fuel Dev Corp | Method and device for recovering palladium by electrolysis method |
| US6024855A (en) * | 1997-08-15 | 2000-02-15 | Sachem, Inc. | Electrosynthesis of hydroxylammonium salts and hydroxylamine using a mediator |
| AU8784198A (en) * | 1997-08-15 | 1999-03-08 | Sachem, Inc. | Electrosynthesis of hydroxylammonium salts and hydroxylamine using a mediator, acatalytic film, methods of making the catalytic film, and electrosynthesis of c ompounds using the catalytic film |
| RU2255150C1 (en) * | 2003-12-04 | 2005-06-27 | Федеральное государственное унитарное предприятие "Научное конструкторско-технологическое бюро "Феррит" | Silver powder production method |
| DE102014204372A1 (en) | 2014-03-11 | 2015-09-17 | Bayer Materialscience Ag | Process for the preparation of catalytically active powders of metallic silver or of mixtures of metallic silver with silver oxide for the production of gas diffusion electrodes |
| RU2558325C1 (en) * | 2014-06-17 | 2015-07-27 | Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Национальный исследовательский технологический университет "МИСиС" | Electrolytic production of fine dispersed silver powders |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB501278A (en) * | 1937-08-21 | 1939-02-21 | Bataafsche Petroleum | Process for manufacturing catalysts and for bringing about catalytic reactions therewith |
-
1971
- 1971-12-28 IT IT33010/71A patent/IT944424B/en active
-
1972
- 1972-11-09 AU AU48663/72A patent/AU476492B2/en not_active Expired
- 1972-11-10 ZA ZA727973A patent/ZA727973B/en unknown
- 1972-11-13 RO RO72798A patent/RO58869A/ro unknown
- 1972-12-06 CS CS8341A patent/CS162787B2/cs unknown
- 1972-12-08 FR FR7243694A patent/FR2186541B1/fr not_active Expired
- 1972-12-08 BR BR8712/72A patent/BR7208712D0/en unknown
- 1972-12-12 GB GB5735772A patent/GB1400758A/en not_active Expired
- 1972-12-12 CH CH1801072A patent/CH556915A/en not_active IP Right Cessation
- 1972-12-15 BE BE792890A patent/BE792890A/en unknown
- 1972-12-18 AR AR245706A patent/AR196221A1/en active
- 1972-12-21 ES ES410294A patent/ES410294A1/en not_active Expired
- 1972-12-26 TR TR17434A patent/TR17434A/en unknown
- 1972-12-27 LU LU66759A patent/LU66759A1/xx unknown
- 1972-12-27 HU HUSA2436A patent/HU165610B/hu unknown
- 1972-12-27 US US00319060A patent/US3843491A/en not_active Expired - Lifetime
- 1972-12-27 DD DD167922A patent/DD103269A5/xx unknown
- 1972-12-27 CA CA159,986A patent/CA1028276A/en not_active Expired
- 1972-12-27 NL NL7217691A patent/NL7217691A/xx not_active Application Discontinuation
- 1972-12-27 YU YU3256/72A patent/YU36103B/en unknown
- 1972-12-28 AT AT1110772A patent/AT333702B/en not_active IP Right Cessation
- 1972-12-28 JP JP13035872A patent/JPS5511895B2/ja not_active Expired
- 1972-12-28 DE DE2263883A patent/DE2263883C3/en not_active Expired
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4302319A (en) * | 1978-08-16 | 1981-11-24 | Katsyguri Ijybi | Continuous electrolytic treatment of circulating washings in the plating process and an apparatus therefor |
| US5413987A (en) * | 1994-01-24 | 1995-05-09 | Midwest Research Institute | Preparation of superconductor precursor powders |
| WO1995020063A1 (en) * | 1994-01-24 | 1995-07-27 | Midwest Research Institute | Preparation of superconductor precursor powders |
| US5789348A (en) * | 1994-01-24 | 1998-08-04 | Midwest Research Institute | Preparation of superconductor precursor powders |
| US5462647A (en) * | 1994-09-09 | 1995-10-31 | Midwest Research Institute | Preparation of lead-zirconium-titanium film and powder by electrodeposition |
| US5785837A (en) * | 1996-01-02 | 1998-07-28 | Midwest Research Institute | Preparation of transparent conductors ferroelectric memory materials and ferrites |
| WO2001051685A3 (en) * | 2000-01-10 | 2002-09-19 | Michael John Sole | Removal of metals from solution |
| CN101579889B (en) * | 2009-06-05 | 2010-10-13 | 黎永健 | Ceramic powder feeding device and feeding method thereof |
| US20130075251A1 (en) * | 2011-09-23 | 2013-03-28 | Bayer Intellectual Property Gmbh | Oxygen-consuming electrode and process for the production thereof |
| US20130075249A1 (en) * | 2011-09-23 | 2013-03-28 | Bayer Intellectual Property Gmbh | Oxygen-consuming electrode and process for production thereof |
| US9118082B2 (en) * | 2011-09-23 | 2015-08-25 | Bayer Intellectual Property Gmbh | Oxygen-consuming electrode and process for the production thereof |
| US9163318B2 (en) * | 2011-09-23 | 2015-10-20 | Bayer Intellectual Property Gmbh | Oxygen-consuming electrode and process for production thereof |
| CN103060854A (en) * | 2013-01-11 | 2013-04-24 | 东南大学 | Method for electrochemical synthesis of colloidal silver solution |
| CN104492428A (en) * | 2014-11-28 | 2015-04-08 | 东莞市青麦田数码科技有限公司 | Silver or bismuth doped zirconium dioxide nanotube as well as preparation method and application thereof |
| CN104492428B (en) * | 2014-11-28 | 2016-09-14 | 东莞市莞信企业管理咨询有限公司 | A kind of Nano tube of zirconium dioxide of silver-doped or bismuth and its production and use |
Also Published As
| Publication number | Publication date |
|---|---|
| ATA1110772A (en) | 1976-04-15 |
| FR2186541B1 (en) | 1976-01-30 |
| AT333702B (en) | 1976-12-10 |
| DE2263883B2 (en) | 1974-10-10 |
| FR2186541A1 (en) | 1974-01-11 |
| NL7217691A (en) | 1973-07-02 |
| AR196221A1 (en) | 1973-12-10 |
| TR17434A (en) | 1975-07-23 |
| CA1028276A (en) | 1978-03-21 |
| BR7208712D0 (en) | 1973-09-20 |
| AU476492B2 (en) | 1976-09-23 |
| CS162787B2 (en) | 1975-07-15 |
| GB1400758A (en) | 1975-07-23 |
| RO58869A (en) | 1975-11-15 |
| DE2263883A1 (en) | 1973-07-19 |
| ZA727973B (en) | 1973-09-26 |
| JPS4873387A (en) | 1973-10-03 |
| CH556915A (en) | 1974-12-13 |
| BE792890A (en) | 1973-03-30 |
| HU165610B (en) | 1974-09-28 |
| IT944424B (en) | 1973-04-20 |
| JPS5511895B2 (en) | 1980-03-28 |
| ES410294A1 (en) | 1976-01-01 |
| YU325672A (en) | 1981-04-30 |
| DD103269A5 (en) | 1974-01-12 |
| YU36103B (en) | 1982-02-25 |
| LU66759A1 (en) | 1973-02-27 |
| AU4866372A (en) | 1974-05-09 |
| DE2263883C3 (en) | 1975-05-28 |
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