CN120037936A - Non-noble metal deoxidizing catalyst and preparation method and application thereof - Google Patents

Abstract

The invention discloses a non-noble metal deoxidizing catalyst, a preparation method and application thereof. The non-noble metal deoxidizing catalyst is obtained by reducing a mixed oxide with a spinel structure, wherein the chemical expression of the mixed oxide with the spinel structure is Mn _xM_(2‑x)Fe₄O₈ in terms of atomic ratio, x is more than or equal to 0.1 and less than or equal to 1.9, and M is at least one of transition metals including Zn, co, cu, ni. The deoxidization active components with uniform mixing and different properties can be obtained by regulating and controlling the reduction process, so that the deoxidization active components are suitable for deoxidization processes of various process gases in different scenes. The non-noble metal deoxidizing catalyst has the advantages of high activity and selectivity, good heat resistance, low cost and the like, and is suitable for deep deoxidization of inert gases such as nitrogen, argon and the like, CO gases, low-carbon olefins, gases containing CO and hydrogen and the like, wherein the residual oxygen content can be as low as less than 1 ppm.

Description

Non-noble metal deoxidizing catalyst and preparation method and application thereof

Technical Field

The invention relates to the technical field of catalysis, in particular to a non-noble metal deoxidizing catalyst, a preparation method and application thereof.

Background

High (ultra) pure gas has become an indispensable raw material in modern industry, especially in the fields of semiconductors, chemical industry, new energy and the like, and is important for the strict control of oxygen content in industrial gas. For example, the presence of trace oxygen in the electronic specialty gas not only can significantly reduce the product quality and the production yield, but also can shorten the service life of equipment and affect the stability of the process, and trace oxygen in the synthesis gas can cause excessive temperature rise of the catalyst bed, thereby changing the structural characteristics of the catalyst, reducing the dispersity of active components and even triggering the sintering deactivation of the catalyst. In addition, during the hydrogen production process (such as water electrolysis hydrogen production or fossil energy hydrogen production), a small amount of oxygen is often mixed, and enrichment of trace oxygen may cause serious explosion risks in the production process. Therefore, how to efficiently and stably deeply remove trace oxygen in industrial gas has become a key technical problem to be solved in the current industrial production.

The catalytic deoxidation method is one of the most commonly used deoxidation methods at present because of the wide application scene, mild reaction conditions, low energy consumption, high selectivity, simple operation and the like. Studies have shown that noble metals such as platinum and palladium have excellent catalytic deoxidizing activity under low temperature conditions. Conventional noble metal deoxygenation catalysts are typically prepared by supporting platinum or palladium on an alumina or silica support. However, since the hydrophobicity of the carrier such as alumina and silica is poor, the prepared catalyst also has low hydrophobicity, and thus it is required to hydrophobicize the catalyst. However, in gas systems containing high carbon monoxide (CO) concentrations, noble metal catalysts are extremely poisoned and reduce the catalytic effect. The silver-based deoxidizing catalyst can avoid the influence of impurities such as CO and the like, and patent application CN114130422A discloses a preparation method of a silver X-type molecular sieve purifying agent for deep deoxidizing, which comprises the steps of fully mixing an X-type molecular sieve with a binder, granulating, and loading silver species on the carrier.

In contrast, non-noble metal deoxidizers have significant price advantages and market competitiveness, and currently mainly include manganese-based, copper-based, and nickel-based deoxidizers. Patent CN100513367C discloses a deoxidizing catalyst with MnO/Mn ₃O₄ as an active component, which can effectively remove low-concentration oxygen (1-2000 ppm) in gases such as ethylene, propylene and the like, but the catalyst is regenerated frequently. Patent application CN101301611A discloses a non-noble metal copper-based deoxidizing catalyst which is mainly suitable for deoxidizing coal bed gas with the oxygen content of 3% -6%, and can only reduce the oxygen content to below 0.5%, and the deoxidizing precision and efficiency are still limited. Patent application CN104667940a discloses a cerium-based composite oxide deoxidizing catalyst, which is prepared by adopting a coprecipitation method, wherein the main components of the catalyst are cerium (Ce) and metal M (M is one or more of Zr, cu, fe, mn, co, ni, zn, S). Although the catalyst can be supported on honeycomb ceramics and applied in a monolithic form, the amount of rare earth cerium is large, resulting in high catalyst cost. In addition, since a plurality of active components are supported by coprecipitation, and the pH value of the coprecipitation required for each component is different, uniformity of the active components is difficult to ensure, thereby affecting performance stability of the catalyst. In addition, the southbound company has proposed a non-noble metal deoxidizing catalyst with nickel as an active center, which can deoxidize under the condition of H ₂ or can chemically deoxidize, and can remove the mixture of nitrogen, argon and hydrocarbon to 5 ppm under the conditions of 200 ℃ and space velocity of 300-500H ^-1, and the deoxidizing capacity reaches 25 mL/g.

In summary, the deoxidization catalyst which has high deoxidization precision and selectivity, good stability and low production cost, is suitable for long-period operation of industrial devices in different scenes is developed, and has important significance for improving the purification efficiency of process gas and reducing the overall operation cost of industrial production.

Disclosure of Invention

The invention provides a non-noble metal deoxidizing catalyst and a preparation method and application thereof, and aims to solve the problems of high catalyst cost, complex preparation process, deoxidizing depth, insufficient selectivity and the like in the prior art. The non-noble metal deoxidizing catalyst is a high-efficiency iron-based non-noble metal catalyst, wherein deoxidizing active components comprise one or more of iron (Fe), manganese (Mn), transition metal (M), carbide, oxide and simple substance thereof, and the like. The deoxidizing active components with uniform mixing and different properties are prepared by regulating and controlling the reduction process. The non-noble metal deoxidizing catalyst has the advantages of high activity and selectivity, high heat-resistant temperature, good heat resistance (for example, the deoxidizing can be performed at 250 ℃ for a long time and high efficiency), low cost and the like, is suitable for deoxidizing various process gases in different scenes, and is particularly suitable for deep deoxidizing systems such as inert gases such as nitrogen, argon and the like, CO gases, low-carbon olefins (C2-C4 olefins including ethylene, propylene, butylene and the like), gases (such as synthesis gas) containing CO and hydrogen and the like, wherein the residual oxygen content can be as low as less than 1 ppm.

The specific technical scheme is as follows:

in a first aspect, the present invention provides a non-noble metal deoxygenation catalyst obtained by reduction of a mixed oxide having a spinel structure;

The chemical expression of the mixed oxide with spinel structure is Mn _xM_(2-x)Fe₄O₈ in terms of atomic ratio, wherein 0.1.ltoreq.x.ltoreq.1.9, M is a transition metal including at least one of zinc (Zn), cobalt (Co), copper (Cu), nickel (Ni), and preferable examples include Zn, or Zn and Co. As one example, M is Zn. As yet another example, M is Zn and Co, and further, the molar ratio of Zn and Co may be 4 to 6:1, for example 5:1, etc.

In the structural design of the catalyst, the ferromanganese has a plurality of different valence states and electronic structures and has stronger oxidation-reduction capability, the electron transfer paths between the ferromanganese and the catalyst can be regulated and controlled by controlling the relative proportion of the ferromanganese and the manganese so as to realize synergistic effect, and further, the micro-characteristics such as the distribution of metal cations, the oxygen lattice energy, the electron state density distribution and the like in the crystal structure can be regulated and controlled by doping different transition metal elements so as to influence the reducibility, the oxidation-reduction capability and the properties and the density of catalytic sites on the surface of the catalyst, thereby regulating and controlling the selectivity and the efficient activation of trace oxygen in different application scenes.

In some preferred embodiments, the non-noble metal deoxygenation catalyst is 0.2.ltoreq.x.ltoreq.1.8, and x may be, for example, 0.5, 0.8, 1, 1.5, 1.6, 1.7, etc.

The Zn, co, cu, ni and other transition metal elements have different 3d electronic configurations and energy level structures, and show different oxygen coordination environments and electron migration characteristics in crystal lattices. When Zn element is used as a main transition metal dopant, as Zn ²⁺ ions have a full 3d ¹⁰ electronic structure, tetrahedral (A) sites tend to be occupied in spinel lattices, so that the lattice oxygen stability is adjusted, the electronic structure regulation of Fe and Mn ions at adjacent octahedral (B) sites is promoted, and the reduction characteristic of the whole crystal is improved. In addition, the bonding energy between oxygen ions and Fe ³⁺/Mn³⁺ can be effectively reduced by introducing Zn, and the activation and desorption of lattice oxygen are promoted, so that the oxygen migration rate and catalytic reaction activity of the catalyst under the deoxidization reaction condition are improved. When Co elements are doped into Zn-based spinel structure oxide, the existence of Co ²⁺/Co³⁺ mixed valence state can introduce rich oxygen vacancies and oxygen defect state, and further optimize electronic structure, so that the catalyst shows higher reducibility and oxygen migration activity. The optimum balance of oxygen migration and reducibility can be obtained by selecting a proper intermediate ratio interval (0.2.ltoreq.x.ltoreq.1.8).

The non-noble metal deoxidizing catalyst may reduce the mixed oxide having a spinel structure using a reducing gas. The catalyst is subjected to reduction treatment by different gases, the type and the composition of the active phase of the deoxidization catalyst are accurately regulated and controlled, and the adsorption and the activity mode of oxygen are further regulated, so that the deoxidization catalyst is suitable for deep deoxidization of various process gases in different scenes. Further, the reducing gas may include at least one of hydrogen, carbon monoxide, and hydrocarbon. Still further, the hydrocarbon may include at least one of ethylene, propylene, acetylene.

In some embodiments, the reducing gas is hydrogen, and the resulting non-noble metal deoxygenation catalyst is particularly useful for deep deoxygenation of systems such as inert gases such as nitrogen, argon, and CO gas, and gases containing both CO and hydrogen (e.g., syngas).

In some embodiments, the reducing gas is one or more of carbon monoxide and hydrocarbon, or a mixed gas of at least one of carbon monoxide and hydrocarbon and hydrogen, and the obtained non-noble metal deoxidizing catalyst is particularly suitable for deep deoxidization of low-carbon olefins (C2-C4 olefins, including ethylene, propylene, butylene and the like), and can show extremely high deoxidizing efficiency and deoxidizing selectivity and remarkably reduce olefin loss. Further, in the mixed gas of the hydrogen and at least one of carbon monoxide and hydrocarbon, the ratio of the volume of the at least one of carbon monoxide and hydrocarbon to the volume of the hydrogen may be 1-2:1, etc.

The temperature of the non-noble metal deoxidizing catalyst may be 200-550 ℃, such as 300 ℃ and 400 ℃, the time of the reduction may be 2-15 hours, such as 5 hours, 6 hours and 10 hours, the temperature rising rate of the reduction may be 2-10 ℃ per minute, such as 5 ℃ per minute, and the pressure of the reduction may be 0.1-1 MPa, such as 0.5MPa, and the like.

In a second aspect, the present invention provides a method for preparing the non-noble metal deoxygenation catalyst according to the first aspect, comprising:

preparing a precursor solution containing a Mn source, a transition metal source and a Fe source;

Mixing the precursor solution and alkali liquor by adopting a co-dripping method to form a mixed liquor;

Carrying out hydrothermal crystallization reaction on the mixed solution, and carrying out solid-liquid separation after the reaction is finished to obtain solid for washing and calcining to obtain the mixed oxide with the spinel structure;

And (3) carrying out reduction treatment on the mixed oxide with the spinel structure to obtain the non-noble metal deoxidizing catalyst.

The mixed oxide precursor with spinel structure prepared by the preparation method has the characteristics of larger specific surface area, uniform particle size and the like, different elements are uniformly mixed, and the method has relatively simple process, strong operability and easy industrial amplification.

The Mn source may be a Mn salt. Further, the Mn salt may include at least one of manganese acetate and manganese nitrate.

The transition metal source may be a transition metal salt. Further, the transition metal salt may include at least one of nitrate, acetate, chloride of a transition metal.

The Fe source may be an Fe salt. Further, the Fe salt may include at least one of ferric nitrate and ferric chloride.

The lye may be a precipitant solution. Further, the precipitant may include at least one of sodium hydroxide (NaOH), sodium carbonate (Na ₂CO₃), urea, ammonia, tetramethylammonium hydroxide, tetrapropylammonium hydroxide.

The pH of the mixed solution can be 9-11, and further can be 9-10, preferably 10, so that the deoxidization performance of the catalyst can be improved.

The temperature of the hydrothermal crystallization reaction may be 30 to 150 ℃, preferably 30 to 60 ℃, for example 50 ℃, etc.

The time of the hydrothermal crystallization reaction may be 2 to 10 hours.

The atmosphere of calcination is air.

The temperature of the calcination may be 400 to 550 ℃, e.g., 450 ℃, etc.

The incubation time for the calcination may be 3 to 6 hours, for example 4 hours, etc.

The calcination may be at a rate of temperature rise of 2 to 10 ℃, for example 5 ℃ per minute.

In a third aspect, the present invention provides the use of a non-noble metal deoxygenation catalyst according to the first aspect or a non-noble metal deoxygenation catalyst prepared according to the preparation method of the second aspect for deoxygenation of an oxygen-containing gas.

In a fourth aspect, the invention provides a deoxidizing method for oxygen-containing gas, which comprises the step of removing oxygen in the oxygen-containing gas by using the non-noble metal deoxidizing catalyst in the first aspect or the non-noble metal deoxidizing catalyst prepared by the preparation method in the second aspect.

The deoxidizing reaction conditions for the deoxidizing method for an oxygen-containing gas of the application of the third aspect, the fourth aspect, may include any one of the following:

The deoxidization reaction temperature is 100 to 300 ℃, for example 130 ℃, 170 ℃, 200 ℃, 220 ℃, 230 ℃, 240 ℃, 250 ℃, etc.;

the deoxidization reaction pressure is 0.1 to 3 MPa, for example 1 MPa, 1.8 MPa, etc.;

The oxygen-containing gas has a volume content of oxygen of not more than 2%, for example 1000 ppm, 0.2%, 0.3%, etc.;

the volume space velocity of the oxygen-containing gas is in the range of 1000 to 5000 h ^-1, such as 2000 h ^-1、3000 h^-1, etc.

In the application of the third aspect and the deoxidizing method for an oxygen-containing gas of the fourth aspect, the oxygen-containing gas may be inert gas such as nitrogen, argon, etc., CO gas, low-carbon olefins (C2-C4 olefins including ethylene, propylene, butylene, etc.), gas containing CO and hydrogen (e.g. synthesis gas), etc.

Compared with the prior art, the invention has the beneficial effects that:

1. The catalyst has the advantages of low cost, simple preparation method, suitability for large-scale industrial production, and good economy and operability, and manganese, iron and transition metal are selected as active components, and the metal compounds are low in price and wide in source.

2. The iron-manganese spinel catalyst prepared by the method has high specific surface area (more than 30m ²g^-1), and can obtain highly dispersed active centers after reduction treatment. Different types of active components including metal simple substances, metal oxides, metal carbides and the like can be formed by selecting different reducing gases, and the method is suitable for deep deoxidization of various gas systems in different scenes. For example, by hydrogen reduction, elemental metal active sites can be formed, thereby achieving deep removal of trace oxygen in synthesis gas and inert gases (e.g., including one or more of nitrogen and noble gases), etc., the deoxygenation depth can be as low as less than 0.5ppm, and by reduction carbonization of one or more of carbon monoxide, hydrocarbon, or a mixture of at least one of carbon monoxide and hydrocarbon with hydrogen, metal carbide active sites can be formed, suitable for deep removal of trace oxygen in light olefins, the deoxygenation depth can be as low as less than 1ppm, and the olefin loss can be as low as less than 1%.

Detailed Description

The invention will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present invention and are not intended to limit the scope of the present invention.

Example 1 preparation of catalyst Mn _1.5Zn_0.5Fe₄O₈ (atomic ratio) and evaluation of properties.

Zinc (II) nitrate, manganese (II) nitrate and iron (III) nitrate were dissolved in 50mL deionized water to prepare a precursor solution containing 0.67: 0.67 mol/L Fe ³⁺ and concentrations of Zn ²⁺ and Mn ²⁺ ions. The total molar concentration of Zn ²⁺ and Mn ²⁺ was fixed at 1/2 of the molar concentration of Fe ³⁺, with a molar concentration ratio of Mn ²⁺ to Zn ²⁺ of 3:1. The precursor solution and 2 mol/L NaOH solution are mixed by adopting a co-dripping method, the pH of the mixed solution is regulated to be about 10, and the mixed solution is subjected to hydrothermal crystallization at 30 ℃ for 2h. The precipitate was then rinsed three times with ultrapure water. Next, the solid product was dried at 100 ℃ overnight, and then calcined in air at 450 ℃ at a rate of rise in temperature of 5 ℃ per minute for 4 hours to give Mn _1.5Zn_0.5Fe₄O₈, a specific surface area of about 40 m ²g^-1.

Mn _1.5Zn_0.5Fe₄O₈ prepared above is firstly reduced under H ₂, the temperature rising rate is 5 ℃ per min, the reduction reaction pressure is 0.1 MPa, the reduction temperature is 400 ℃, the reduction time is 2H, the deoxidization reaction temperature is shown in Table 1, the fixed bed, the catalyst 1 g, the airspeed 3000H ^-1, the deoxidization reaction pressure is 1.8 MPa, the deoxidization reaction gas comprises 1000 ppm of oxygen volume, 0.65vol% of 1, 3-butadiene, 0.089vol% of acetylene, 12.408vol% of hydrogen and the balance of balance gas N ₂. The oxygen concentration at the outlet was measured using a micro oxygen analyzer, and the hydrocarbon was analyzed by on-line gas chromatography, and the reaction results for 5 hours are shown in table 1.

TABLE 1

Example 2 preparation of catalyst Mn _1.5Ni_0.5Fe₄O₈ (atomic ratio) and evaluation of properties.

Nickel (II) nitrate, manganese (II) nitrate and iron (III) nitrate were dissolved in 50mL deionized water to prepare a precursor solution containing 0.67 mol/L Fe ³⁺ and concentrations of Ni ²⁺ and Mn ²⁺ ions. The total molar concentration of Ni ²⁺ and Mn ²⁺ was fixed at 1/2 of the molar concentration of Fe ³⁺, with a molar concentration ratio of Mn ²⁺ to Ni ²⁺ of 3:1. Other preparation procedures were the same as in example 1 to give Mn _1.5Ni_0.5Fe₄O₈.

Mn _1.5Ni_0.5Fe₄O₈ prepared above is firstly reduced under H ₂, the temperature rising rate is 5 ℃ per min, the reduction reaction pressure is 0.1 MPa, the reduction temperature is 400 ℃, the reduction time is 2H, the deoxidization reaction temperature is shown in Table 2, the fixed bed, the catalyst 1 g, the space velocity 3000H ^-1, the deoxidization reaction pressure is 1.8 MPa, the deoxidization reaction gas comprises 1000 ppm of oxygen volume, 0.65vol% of 1, 3-butadiene, 0.089vol% of acetylene, 12.408vol% of hydrogen and the balance of balance gas N ₂. The oxygen concentration at the outlet was measured using a micro oxygen analyzer, and the hydrocarbon was analyzed by on-line gas chromatography, and the reaction results for 5 hours are shown in Table 2.

TABLE 2

Example 3 preparation of catalyst Mn _1.7Co_0.3Fe₄O₈ (atomic ratio) and evaluation of properties.

Cobalt (II) nitrate, manganese (II) nitrate and iron (III) nitrate were dissolved in 50 mL deionized water to prepare a precursor solution containing 0.67 mol/L Fe ³⁺ and concentrations of Co ²⁺ and Mn ²⁺ ions. The total molar concentration of Co ²⁺ and Mn ²⁺ was fixed at 1/2 of the molar concentration of Fe ³⁺, with a molar concentration ratio of Mn ²⁺ to Co ²⁺ of 17:3. Other preparation procedures were the same as in example 1 to give Mn _1.7Co_0.3Fe₄O₈.

Mn _1.7Co_0.3Fe₄O₈ prepared above is firstly reduced under H ₂, the temperature rising rate is 5 ℃ per min, the reduction reaction pressure is 0.1 MPa, the reduction temperature is 400 ℃, the reduction time is 2H, the deoxidization reaction temperature is shown in Table 3, the fixed bed, the catalyst 1 g, the space velocity 3000H ^-1, the deoxidization reaction pressure is 1.8 MPa, the deoxidization reaction gas comprises 1000 ppm of oxygen volume, 0.65vol% of 1, 3-butadiene, 0.089vol% of acetylene, 12.408vol% of hydrogen and the balance of balance gas N ₂. The oxygen concentration at the outlet was measured using a micro oxygen analyzer, and the hydrocarbon was analyzed by on-line gas chromatography, and the reaction results for 5 hours are shown in Table 3.

TABLE 3 Table 3

Example 4 preparation of catalyst Mn _1.5Zn_0.5Fe₄O₈ (atomic ratio) and evaluation of properties.

Mn _1.5Zn_0.5Fe₄O₈ was prepared as in example 1.

Mn _1.5Zn_0.5Fe₄O₈ prepared above was charged into a fixed bed reactor to perform reduction treatment. The reduction conditions are that the volume ratio of CO to H ₂ is 2:1, the reduction temperature is 300 ℃, the reduction time is 5 hours, the heating rate is 2 ℃ per minute, and the reduction reaction pressure is 0.5 MPa. And (3) after reduction treatment, obtaining the non-noble metal iron-based deoxidizing catalyst.

Deoxygenation test conditions feed gas (volume fraction: 98% propylene/0.2% oxygen/1.8% hydrogen) containing propylene, oxygen and hydrogen was introduced into the above fixed bed reactor to conduct gas phase deoxygenation reaction. The deoxidization reaction condition is that the space velocity is 2000 h ^-1, the reaction pressure is 1 MPa, and the reaction temperature is 230 ℃. At the reaction outlet, the residual oxygen concentration was detected by a micro oxygen analyzer, and the hydrocarbon was analyzed by on-line gas chromatography. The result of the 5-hour reaction showed that the loss of propylene was 0.5% and the residual oxygen concentration was 0.6 ppm%.

Example 5 preparation of catalyst Mn _1.5Cu_0.5Fe₄O₈ (atomic ratio) and evaluation of properties.

Copper (II) nitrate, manganese (II) nitrate and iron (III) nitrate were dissolved in 50mL deionized water to prepare a precursor solution containing 0.67 mol/L Fe ³⁺ and concentrations of Cu ²⁺ and Mn ²⁺ ions. The total molar concentration of Cu ²⁺ and Mn ²⁺ was fixed at 1/2 of the molar concentration of Fe ³⁺, with a molar concentration ratio of Mn ²⁺ to Cu ²⁺ of 3:1. Other preparation procedures were the same as in example 1 to give Mn _1.5Cu_0.5Fe₄O₈.

Mn _1.5Cu_0.5Fe₄O₈ prepared above was charged into a fixed bed reactor to perform reduction treatment. The reduction conditions are that the volume ratio of CO to H ₂ is 2:1, the reduction temperature is 300 ℃, the reduction time is 5 hours, the heating rate is 2 ℃ per minute, and the reduction reaction pressure is 0.5 MPa. And (3) after reduction treatment, obtaining the non-noble metal iron-based deoxidizing catalyst.

Deoxygenation test conditions feed gas (volume fraction: 98% propylene/0.2% oxygen/1.8% hydrogen) containing propylene, oxygen and hydrogen was introduced into the above fixed bed reactor to conduct gas phase deoxygenation reaction. The deoxidization reaction condition is that the space velocity is 2000 h ^-1, the reaction pressure is 1 MPa, and the reaction temperature is 230 ℃. At the reaction outlet, the residual oxygen concentration was detected by a micro oxygen analyzer, and the hydrocarbon was analyzed by on-line gas chromatography. The result of the 5-hour reaction showed that the loss of propylene was 0.3% and the residual oxygen concentration was 0.9 ppm.

Example 6 preparation of catalyst Mn _1.6Co_0.4Fe₄O₈ (atomic ratio) and evaluation of properties.

Cobalt (II) nitrate, manganese (II) nitrate and iron (III) nitrate were dissolved in 50mL deionized water to prepare a precursor solution containing 0.67 mol/L Fe ³⁺ and concentrations of Co ²⁺ and Mn ²⁺ ions. The total molar concentration of Co ²⁺ and Mn ²⁺ was fixed at 1/2 of the molar concentration of Fe ³⁺, with a molar concentration ratio of Mn ²⁺ to Co ²⁺ of 4:1. Other preparation procedures were the same as in example 1 to give Mn _1.6Co_0.4Fe₄O₈.

Mn _1.6Co_0.4Fe₄O₈ prepared above was charged into a fixed bed reactor to perform reduction treatment. The reduction conditions are that the volume ratio of the reduction atmosphere is 1:1, the reduction temperature is 300 ℃, the reduction time is 5 hours, the temperature rising rate is 2 ℃ per minute, and the reduction reaction pressure is 0.5 MPa. And (3) after reduction treatment, obtaining the non-noble metal iron-based deoxidizing catalyst.

Deoxygenation test conditions feed gas (volume fraction: 98% propylene/0.2% oxygen/1.8% hydrogen) containing propylene, oxygen and hydrogen was introduced into the above fixed bed reactor to conduct gas phase deoxygenation reaction. The deoxygenation reaction condition was a space velocity of 2000 h ^-1, a reaction pressure of 1 MPa, and a reaction temperature of 240 ℃. At the reaction outlet, the residual oxygen concentration was detected by a micro oxygen analyzer, and the hydrocarbon was analyzed by on-line gas chromatography. The result of the 5-hour reaction showed that the loss of propylene was 0.6% and the residual oxygen concentration was 0.6 ppm.

Example 7 preparation of catalyst Mn _0.8ZnCo_0.2Fe₄O₈ (atomic ratio) and evaluation of properties.

Zinc (II) nitrate, manganese (II) nitrate, cobalt (II) nitrate and iron (III) nitrate were dissolved in 50 mL di water to prepare a precursor solution containing 0.67: 0.67 mol/L Fe ³⁺ and a concentration of Zn ²⁺、CO²⁺、Mn²⁺ ions. The total molar concentration of Zn ²⁺、Co²⁺ and Mn ²⁺ was fixed at 1/2 of the molar concentration of Fe ³⁺, and the molar concentration ratio of Zn ²⁺、CO²⁺ and Mn ²⁺ was 1:0.2:0.8. Other preparation procedures were the same as in example 1 to give Mn _0.8ZnCo_0.2Fe₄O₈.

Mn _0.8ZnCo_0.2Fe₄O₈ prepared above was charged into a fixed bed reactor to perform reduction treatment. The reduction conditions are that the reduction atmosphere is CO, the reduction temperature is 300 ℃, the reduction time is 6 hours, the heating rate is 2 ℃ per minute, and the reaction pressure is 0.1 MPa. And (3) after reduction treatment, obtaining the non-noble metal iron-based deoxidizing catalyst.

Deoxygenation test conditions feed gas (volume fraction: 98% propylene/0.3% oxygen/1.7% hydrogen) containing propylene, oxygen and hydrogen was introduced into the above fixed bed reactor to conduct gas phase deoxygenation reaction. The deoxidization reaction condition is that the space velocity is 2000 h ^-1, the reaction pressure is 1 MPa, and the reaction temperature is 230 ℃. At the reaction outlet, the residual oxygen concentration was detected by a micro oxygen analyzer, and the hydrocarbon was analyzed by on-line gas chromatography. The result of the 5-hour reaction showed that the loss of propylene was 0.3% and the residual oxygen concentration was 0.9 ppm.

Example 8 preparation of catalyst Mn _1.8Zn_0.2Fe₄O₈ (atomic ratio) and evaluation of properties.

Zinc (II) nitrate, manganese (II) nitrate and iron (III) nitrate were dissolved in 50mL deionized water to prepare a precursor solution containing 0.67: 0.67 mol/L Fe ³⁺ and concentrations of Zn ²⁺ and Mn ²⁺ ions. The total molar concentration of Zn ²⁺ and Mn ²⁺ was fixed at 1/2 of the molar concentration of Fe ³⁺, with a molar concentration ratio of Mn ²⁺ to Zn ²⁺ of 9:1. Other preparation procedures were the same as in example 1 to give Mn _1.8Zn_0.2Fe₄O₈.

Mn _1.8Zn_0.2Fe₄O₈ prepared above was first reduced in a fixed bed reactor under H ₂ at a heating rate of 5℃per minute, a reduction reaction pressure of 0.1. 0.1 MPa, a reduction temperature of 400℃and a reduction time of 2H. And (3) after reduction treatment, obtaining the non-noble metal iron-based deoxidizing catalyst.

Deoxygenation test conditions feed gas containing CO and hydrogen (volume fraction of CO and hydrogen about 1:1, oxygen content about 0.2 vol%) was fed into the above fixed bed reactor for a long period of gas phase deoxygenation reaction. The deoxygenation reaction condition was a space velocity of 2000 h ^-1, a reaction pressure of 1 MPa and a reaction temperature of 250 ℃. At the reaction outlet, the residual oxygen concentration was detected by a micro oxygen analyzer, and the hydrocarbon was analyzed by an on-line gas chromatograph, and the reaction results are shown in table 4.

TABLE 4 Table 4

Further, it is to be understood that various changes and modifications of the present application may be made by those skilled in the art after reading the above description of the application, and that such equivalents are intended to fall within the scope of the application as defined in the appended claims.

Claims (10)

1. A non-precious metal deoxidation catalyst, characterized in that the non-precious metal deoxidation catalyst is obtained by reducing a mixed oxide having a spinel structure; In terms of atomic ratio, the chemical expression of the mixed oxide having a spinel structure is Mn _x M _(2-x) Fe ₄ O ₈ , wherein 0.1≤x≤1.9, and M is a transition metal, including at least one of Zn, Co, Cu, and Ni. 2. The non-precious metal deoxidation catalyst according to claim 1, characterized in that 0.2≤x≤1.8. 3. The non-precious metal deoxidation catalyst according to claim 1, characterized in that the mixed oxide having a spinel structure is reduced using a reducing gas; The reducing gas includes at least one of hydrogen, carbon monoxide, and hydrocarbons; The hydrocarbon includes at least one of ethylene, propylene and acetylene. 4. The non-precious metal deoxidation catalyst according to claim 1, characterized in that the reduction temperature is 200-550° C., the reduction time is 2-15 hours, the reduction heating rate is 2-10° C./min, and the reduction pressure is 0.1-1 MPa. 5. The method for preparing a non-precious metal deoxidation catalyst according to any one of claims 1 to 4, characterized in that it comprises: preparing a precursor solution containing a Mn source, a transition metal source and an Fe source; The precursor solution and the alkaline solution are mixed to form a mixed solution by a co-dropping method; Performing a hydrothermal crystallization reaction on the mixed solution, and after the reaction is completed, separating the solid from the liquid, washing and calcining the solid to obtain the mixed oxide having a spinel structure; The mixed oxide with a spinel structure is subjected to reduction treatment to obtain the non-precious metal deoxidation catalyst. 6. The preparation method according to claim 5, characterized in that the Mn source is a Mn salt, and the Mn salt comprises at least one of manganese acetate and manganese nitrate; The transition metal source is a transition metal salt, and the transition metal salt includes at least one of a nitrate, an acetate, and a chloride of a transition metal; The Fe source is an Fe salt, and the Fe salt includes at least one of ferric nitrate and ferric chloride; The alkali solution is a precipitant solution, and the precipitant includes at least one of sodium hydroxide, sodium carbonate, urea, ammonia water, tetramethylammonium hydroxide, and tetrapropylammonium hydroxide. 7. The preparation method according to claim 5 or 6, characterized in that the pH of the mixed solution is 9-11; The temperature of the hydrothermal crystallization reaction is 30 to 150° C., and the time of the hydrothermal crystallization reaction is 2 to 10 hours; The calcination atmosphere is air; the calcination temperature is 400 to 550° C., the calcination holding time is 3 to 6 hours, and the calcination heating rate is 2 to 10° C./min. 8. Use of the non-precious metal deoxidation catalyst according to any one of claims 1 to 4 or the non-precious metal deoxidation catalyst prepared according to the preparation method according to any one of claims 5 to 7 in deoxidation of oxygen-containing gas. 9. A method for deoxygenating an oxygen-containing gas, characterized in that it comprises: removing oxygen from the oxygen-containing gas using the non-precious metal deoxygenation catalyst according to any one of claims 1 to 4 or the non-precious metal deoxygenation catalyst prepared by the preparation method according to any one of claims 5 to 7. 10. The method for deoxygenating oxygen-containing gas according to claim 9, characterized in that the deoxygenation reaction conditions of the method for deoxygenating oxygen-containing gas include any of the following: The deoxidation reaction temperature is 100 to 300°C; The deoxygenation reaction pressure is 0.1 to 3 MPa; The volume content of oxygen in the oxygen-containing gas is not higher than 2%; The volume space velocity of the oxygen-containing gas is 1000 to 5000 h ^-1 .