A non-noble metal deoxidation catalyst, its preparation method and application

Abstract

The present invention discloses a non-noble metal deoxidation catalyst, a preparation method thereof and an application. The non-noble metal deoxidation catalyst is obtained by reducing a mixed oxide having a spinel structure; in terms of atomic ratio, the chemical formula of the mixed oxide having a spinel structure is Mn x M (2‑x) Fe4O8, where 0.1 ≤ x ≤ 1.9, and M is a transition metal including at least one of Zn, Co, Cu, and Ni. The present invention can obtain deoxidation active components with uniform mixing and different properties by regulating the reduction process, and is thus applicable to the deoxidation process of various process gases in different scenarios. The non-noble metal deoxidation catalyst of the present invention has the advantages of high activity and selectivity, good heat resistance, low cost, etc., and is applicable to the deep deoxidation of systems such as inert gases such as nitrogen and argon, CO gas, lower olefins, and gases containing both CO and hydrogen, where the residual oxygen content can be as low as less than 1 ppm.

Description

Technical Field

[0001] The present invention relates to the field of catalytic technology, and in particular to a non-precious metal deoxidation catalyst and a preparation method and application thereof. Background Art

[0002] High (ultra) pure gas has become an indispensable raw material in modern industry, especially in the fields of semiconductors, chemicals and new energy. Strict control of the oxygen content in industrial gases is crucial. For example, the presence of trace oxygen in electronic specialty gases will not only significantly reduce product quality and production yield, but may also shorten the service life of equipment and affect the stability of the process; trace oxygen in synthesis gas will cause the temperature rise of the catalyst bed to be too high, thereby changing the structural characteristics of the catalyst, reducing the dispersion of active components, and even causing catalyst sintering and deactivation. In addition, in the process of hydrogen preparation (such as hydrogen production from water electrolysis or fossil energy), a small amount of oxygen is often mixed in, and the enrichment of trace oxygen may lead to serious explosion risks in the production process. Therefore, how to efficiently and stably remove trace oxygen in industrial gases has become a key technical problem that needs to be solved in current industrial production.

[0003] Catalytic deoxygenation has become one of the most commonly used deoxygenation methods due to its wide range of application scenarios, mild reaction conditions, low energy consumption, high selectivity and simple operation. Studies have shown that precious metals such as platinum and palladium have excellent catalytic deoxygenation activity under low temperature conditions. Traditional precious metal deoxygenation catalysts are usually prepared by loading platinum or palladium on alumina or silica carriers. However, due to the poor hydrophobicity of carriers such as alumina and silica, the prepared catalyst also has low hydrophobicity, so it needs to be hydrophobically modified. However, in a gas system containing a high concentration of carbon monoxide (CO), precious metal catalysts are easily poisoned, reducing the catalytic effect. Silver-based deoxygenation catalysts can avoid the influence of impurities such as CO. Patent application CN114130422A discloses a method for preparing a silver X-type molecular sieve purifier for deep deoxygenation. The X molecular sieve is fully mixed with a binder and then granulated, and then the silver species is loaded on the carrier. The prepared catalyst has a high loading rate and good deoxygenation effect, but the high cost of precious metal catalysts limits their large-scale industrial application.

[0004] In contrast, non-noble metal deoxidizers have obvious price advantages and market competitiveness. Currently, they mainly include manganese-based, copper-based, and nickel-based deoxidizers. Patent CN100513367C discloses a deoxidation catalyst with MnO / Mn3O4 as the active component. This catalyst can effectively remove low-concentration oxygen (1 - 2000 ppm) in gases such as ethylene and propylene, but the catalyst needs to be regenerated frequently. Patent application CN101301611A discloses a non-noble metal copper-based deoxidation catalyst, which is mainly applicable to the deoxidation of coalbed methane with an oxygen content of 3% - 6%. It can only reduce the oxygen content to below 0.5%, and the deoxidation accuracy and efficiency are still limited. Patent application CN104667940A discloses a cerium-based composite oxide deoxidation catalyst, whose main components are cerium (Ce) and metal M (M is one or several of Zr, Cu, Fe, Mn, Co, Ni, Zn, S), and it is prepared by the co-precipitation method. Although this catalyst can be supported on honeycomb ceramics for integral application, the dosage of rare earth metal cerium is large, resulting in a high cost of the catalyst. In addition, due to the co-precipitation loading of multiple active components, and the required co-precipitation pH values of each component are different, it is difficult to ensure the uniformity of the active components, thus affecting the performance stability of the catalyst. In addition, Nanhua Company once introduced a non-noble metal deoxidation catalyst with nickel as the active center, which can deoxidize under the condition of H2 and can also be used for chemical deoxidation. At 200 °C and a space velocity of 300 - 500 h -1 conditions, it can deoxidize the mixed gas of nitrogen, argon, and hydrocarbons to 5 ppm, and the deoxidation capacity reaches 25 mL / g.

[0005] In summary, developing a deoxidation catalyst with high deoxidation accuracy and selectivity, good stability, low production cost, and suitable for long-term operation of industrial devices in different scenarios is of great significance for improving the purification efficiency of process gas and reducing the overall operating cost of industrial production. Summary of the Invention

[0006] The present invention provides a non-noble metal deoxidation catalyst, a preparation method thereof and an application thereof, aiming to solve the problems of high catalyst cost, complex preparation process, insufficient deoxidation depth and selectivity in the prior art. The non-noble metal deoxidation catalyst of the present invention is an efficient iron-based non-noble metal catalyst, and the deoxidation active components therein include one or more of iron (Fe), manganese (Mn), transition metal (M) and their carbides, oxides, and simple substances. The present invention prepares deoxidation active components with uniform mixing and different properties by regulating the reduction process. The non-noble metal deoxidation catalyst of the present invention has the advantages of high activity and selectivity, high heat-resistant temperature, good heat resistance (for example, it can efficiently deoxidize for a long time at 250 °C), low cost, etc., and is suitable for the deoxidation process of various process gases in different scenarios, especially for the deep deoxidation of inert gases such as nitrogen and argon, CO gas, lower olefins (C2-C4 olefins, including ethylene, propylene, butene, etc.), and gases containing both CO and hydrogen (such as syngas), etc. The residual oxygen content can be as low as less than 1 ppm.

[0007] The specific technical solutions are as follows:

[0008] In the first aspect, the present invention provides a non-noble metal deoxidation catalyst, and the non-noble metal deoxidation catalyst is obtained by reducing a mixed oxide having a spinel structure;

[0009] In terms of atomic ratio, the chemical formula of the mixed oxide having a spinel structure is Mn x M (2-x) Fe4O8, where 0.1 ≤ x ≤ 1.9, M is a transition metal, including at least one of zinc (Zn), cobalt (Co), copper (Cu), and nickel (Ni), and preferred examples include Zn, or Zn and Co. As one example, M is Zn. As another example, M is Zn and Co. Further, the molar ratio of Zn and Co can be 4-6:1, such as 5:1, etc.

[0010] In the catalyst structure design, iron and manganese have multiple different valence states and electronic structures, and have strong redox capabilities; by controlling the relative ratio of iron and manganese, the electron transfer path between the two in the catalyst can be regulated, so as to achieve a synergistic effect; further by doping different transition metal elements, the distribution of metal cations in the crystal structure, oxygen lattice energy, electron density of states distribution and other microscopic characteristics can be further regulated, thereby affecting the reducibility, redox ability of the catalyst, and the nature and density of catalytic sites on the catalyst surface, so as to regulate the selectivity and efficient activation of trace oxygen in different application scenarios.

[0011] In some preferred examples, for the non-noble metal deoxidation catalyst, 0.2 ≤ x ≤ 1.8. For example, x can be 0.5, 0.8, 1, 1.5, 1.6, 1.7, etc.

[0012] Transition metal elements such as Zn, Co, Cu, and Ni have different 3d electron configurations and energy level structures, showing different oxygen coordination environments and electron migration characteristics in the lattice. When Zn element is used as the main transition metal dopant, since Zn 2+ ions have a full 3d 10 electron structure and tend to occupy the tetrahedral (A) sites in the spinel lattice, which helps to adjust the lattice oxygen stability, promote the electron structure regulation of adjacent octahedral (B)-site Fe and Mn ions, and further improve the reduction characteristics of the overall crystal. In addition, the introduction of Zn can effectively reduce the bonding energy between oxygen ions and Fe 3+ / Mn 3+ and promote the activation and desorption of lattice oxygen, thereby increasing the oxygen migration rate and catalytic reaction activity of the catalyst under deoxidation reaction conditions. When Co element is co-doped into the Zn-based spinel structure oxide, the existence of Co 2+ / Co 3+ mixed valence states will introduce abundant oxygen vacancies and oxygen defect states, and further optimize the electron structure, making the catalyst exhibit higher reducibility and oxygen migration activity. Selecting an appropriate intermediate ratio range (0.2 ≤ x ≤ 1.8) can achieve the optimal balance of oxygen migration and reducibility.

[0013] For the non-noble metal deoxidation catalyst described above, the mixed oxide with spinel structure can be reduced using a reducing gas. By reducing the catalyst with different gases, the type and composition of the active phase of the deoxidation catalyst can be precisely controlled, and then the adsorption and activation mode of oxygen can be adjusted, so as to be applicable to the deep deoxidation of various process gases in different scenarios. Further, the reducing gas may include at least one of hydrogen, carbon monoxide, and hydrocarbons. Still further, the hydrocarbons may include at least one of ethylene, propylene, and acetylene.

[0014] In some embodiments, the reducing gas is hydrogen, and the obtained non-noble metal deoxidation catalyst is particularly suitable for the deep deoxidation of systems such as inert gases like nitrogen and argon, CO gas, and gases containing both CO and hydrogen (such as syngas).

[0015] In some embodiments, the reducing gas is one or more of carbon monoxide and hydrocarbons, or a mixture of at least one of carbon monoxide and hydrocarbons and hydrogen. The obtained non-noble metal deoxidation catalyst is particularly suitable for the deep deoxidation of light olefins (C2 - C4 olefins, including ethylene, propylene, butene, etc.), and can exhibit extremely high deoxidation efficiency and deoxidation selectivity, significantly reducing olefin loss. Further, in the mixture of at least one of carbon monoxide and hydrocarbons and hydrogen, the volume ratio of at least one of carbon monoxide and hydrocarbons to the volume of hydrogen can be 1 - 2:1, etc.

[0016] For the non-noble metal deoxidation catalyst described above, the reduction temperature can be 200-550°C, such as 300°C, 400°C, etc., the reduction time can be 2-15 hours, such as 5 hours, 6 hours, 10 hours, etc., the heating rate of reduction can be 2-10°C / min, such as 5°C / min, etc., and the reduction pressure can be 0.1-1 MPa, such as 0.5 MPa, etc.

[0017] In a second aspect, the present invention provides a method for preparing the non-noble metal deoxidation catalyst according to the first aspect, comprising:

[0018] Preparing a precursor solution containing a Mn source, a transition metal source and an Fe source;

[0019] Mixing the precursor solution and an alkali solution by a co-dripping method to form a mixed solution;

[0020] Performing a hydrothermal crystallization reaction on the mixed solution, separating the solid and liquid after the reaction is completed, washing and calcining the solid to obtain the mixed oxide having a spinel structure;

[0021] Performing a reduction treatment on the mixed oxide having a spinel structure to obtain the non-noble metal deoxidation catalyst.

[0022] The mixed oxide precursor having a spinel structure prepared by the preparation method according to the present invention has characteristics such as a large specific surface area and uniform particle size; different elements are uniformly mixed, and the method has relatively simple process, strong operability and is easy to scale up industrially.

[0023] The Mn source can be a Mn salt. Further, the Mn salt can include at least one of manganese acetate and manganese nitrate.

[0024] The transition metal source can be a transition metal salt. Further, the transition metal salt can include at least one of nitrates, acetates and chlorides of transition metals.

[0025] The Fe source can be an Fe salt. Further, the Fe salt can include at least one of iron nitrate and iron chloride.

[0026] The alkali solution can be a precipitant solution. Further, the precipitant can include at least one of sodium hydroxide (NaOH), sodium carbonate (Na2CO3), urea, ammonia water, tetramethylammonium hydroxide and tetrapropylammonium hydroxide.

[0027] The pH of the mixed solution can be 9-11, further can be 9-10, and preferably 10, which is beneficial to improving the deoxidation performance of the catalyst.

[0028] The temperature of the hydrothermal crystallization reaction can be 30 to 150 °C, preferably 30 to 60 °C, such as 50 °C, etc.

[0029] The time of the hydrothermal crystallization reaction can be 2 to 10 hours.

[0030] The atmosphere for the calcination is air.

[0031] The temperature of the calcination can be 400 to 550 °C, such as 450 °C, etc.

[0032] The heat preservation time of the calcination can be 3 to 6 hours, such as 4 hours, etc.

[0033] The heating rate of the calcination can be 2 to 10 °C / min, such as 5 °C / min.

[0034] In the third aspect, the present invention provides an application of the non-noble metal deoxidation catalyst according to the first aspect or the non-noble metal deoxidation catalyst prepared by the preparation method according to the second aspect in the deoxidation of oxygen-containing gas.

[0035] In the fourth aspect, the present invention provides a method for deoxidizing oxygen-containing gas, including: removing oxygen in the oxygen-containing gas by using the non-noble metal deoxidation catalyst according to the first aspect or the non-noble metal deoxidation catalyst prepared by the preparation method according to the second aspect.

[0036] The deoxidation reaction conditions for the application described in the third aspect and the method for deoxidizing oxygen-containing gas described in the fourth aspect may include any of the following:

[0037] The deoxidation reaction temperature is 100 to 300 °C, such as 130 °C, 170 °C, 200 °C, 220 °C, 230 °C, 240 °C, 250 °C, etc.;

[0038] The deoxidation reaction pressure is 0.1 to 3 MPa, such as 1 MPa, 1.8 MPa, etc.;

[0039] The volume content of oxygen in the oxygen-containing gas is not higher than 2%, such as 1000 ppm, 0.2%, 0.3%, etc.;

[0040] The volume space velocity of the oxygen-containing gas is 1000 to 5000 h -1 e.g., 2000 h -1 、3000 h -1 etc.

[0041] In the application described in the third aspect and the method for deoxidizing oxygen-containing gas described in the fourth aspect, the oxygen-containing gas can be an inert gas such as nitrogen, argon, etc., CO gas, lower olefins (C2-C4 olefins, including ethylene, propylene, butene, etc.), a gas containing both CO and hydrogen (such as syngas), etc.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] 1. Non-noble metal active center, low cost: Manganese, iron, and transition metals are selected as active components in the present invention. Considering that these metal compounds are inexpensive and widely available; moreover, the catalyst preparation method is simple, suitable for large-scale industrial production, and has good economy and operability.

[0044] 2. High catalytic activity, low removal depth, and wide application range: The iron-manganese spinel catalyst prepared in the present invention has a relatively high specific surface area (greater than 30 m 2 g -1 ), and highly dispersed active centers can be obtained after reduction treatment. By selecting different reducing gases, different types of active components can be formed, including elemental metals, metal oxides, metal carbides, etc., which are suitable for deep deoxidation of various gas systems in different scenarios. For example, by reduction with hydrogen, elemental metal active centers can be formed, thereby achieving deep removal of trace oxygen in syngas and inert gases (such as one or more combinations of nitrogen, noble gases, etc.), and the deoxidation depth can be as low as less than 0.5 ppm; by reduction and carbonization using one or more of carbon monoxide, hydrocarbons, or a mixture of at least one of carbon monoxide, hydrocarbons and hydrogen, metal carbide active centers can be formed, which are suitable for deep removal of trace oxygen in light olefins, and the deoxidation depth can be as low as less than 1 ppm, and the olefin loss can be as low as less than 1%. Detailed implementation manners

[0045] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0046] Example 1: Preparation and performance evaluation of catalyst Mn 1.5 Zn 0.5 Fe4O8 (atomic ratio).

[0047] Zinc(II) nitrate, manganese(II) nitrate, and iron(III) nitrate were dissolved in 50 mL of deionized water to prepare a precursor solution containing 0.67 mol / L Fe 3+ and a certain concentration 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+ The molar concentration of Mn 2+ and Zn 2+The molar concentration ratio is 3:1. The precursor solution and 2 mol / L NaOH solution were mixed by the co-dripping method, and the pH of the mixed solution was adjusted to about 10; the mixed solution was hydrothermally crystallized at 30 °C for 2 h. Then the precipitate was rinsed three times with ultrapure water. Next, the solid product was dried overnight at 100 °C and then calcined in air at 450 °C at a heating rate of 5 °C / min for 4 hours to obtain Mn 1.5 Zn 0.5 Fe4O8, with a specific surface area of about 40 m 2 g -1 .

[0048] The above-prepared Mn 1.5 Zn 0.5 Fe4O8 was first reduced under H2 conditions, with a heating rate of 5 °C / min, a reduction reaction pressure of 0.1 MPa, a reduction temperature of 400 °C, and a reduction time of 2 h. The deoxidation reaction temperature is shown in Table 1. Fixed bed, 1 g of catalyst, space velocity 3000 h -1 , deoxidation reaction pressure 1.8 MPa; deoxidation reaction gas: oxygen volume content 1000 ppm, 1,3-butadiene 0.65 vol%, acetylene 0.089 vol%, hydrogen 12.408 vol%, and the rest is the balance gas N2. The oxygen concentration at the outlet was detected using a micro-oxygen analyzer, and the hydrocarbons were analyzed by on-line gas chromatography. The reaction results for 5 hours are shown in Table 1.

[0049] Table 1

[0050]

[0051] Example 2: Preparation and performance evaluation of the catalyst Mn 1.5 Ni 0.5 Fe4O8 (atomic ratio).

[0052] Nickel(II) nitrate, manganese(II) nitrate, and iron(III) nitrate were dissolved in 50 mL of deionized water to prepare a precursor solution containing 0.67 mol / L Fe 3+ and a certain concentration 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+ , and the molar concentration ratio of Mn 2+ to Ni 2+ was 3:1. Other preparation steps were the same as in Example 1 to obtain Mn 1.5 Ni 0.5 Fe4O8.

[0053] The above-prepared Mn 1.5Ni 0.5 Fe4O8 was first reduced under H2 conditions. The heating rate was 5 °C / min, the reduction reaction pressure was 0.1 MPa, the reduction temperature was 400 °C, and the reduction time was 2 h. The deoxidation reaction temperature is shown in Table 2. Fixed bed, 1 g of catalyst, space velocity 3000 h -1 , the deoxidation reaction pressure was 1.8 MPa; the deoxidation reaction gas: the oxygen volume content was 1000 ppm, 1,3-butadiene was 0.65 vol%, acetylene was 0.089 vol%, hydrogen was 12.408 vol%, and the rest was the balance gas N2. The oxygen concentration at the outlet was detected using a micro-oxygen analyzer, and the hydrocarbons were analyzed by on-line gas chromatography. The reaction results for 5 hours are shown in Table 2.

[0054] Table 2

[0055]

[0056] Example 3: Catalyst Mn 1.7 Co 0.3 Preparation and performance evaluation of Fe4O8 (atomic ratio).

[0057] Cobalt(II) nitrate, manganese(II) nitrate and iron(III) nitrate were dissolved in 50 mL of deionized water to prepare a precursor solution containing 0.67 mol / L Fe 3+ and a certain concentration 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+ , and the molar concentration ratio of Mn 2+ to Co 2+ was 17:3. Other preparation steps were the same as in Example 1 to obtain Mn 1.7 Co 0.3 Fe4O8.

[0058] The above-prepared Mn 1.7 Co 0.3 Fe4O8 was first reduced under H2 conditions. The heating rate was 5 °C / min, the reduction reaction pressure was 0.1 MPa, the reduction temperature was 400 °C, and the reduction time was 2 h. The deoxidation reaction temperature is shown in Table 3. Fixed bed, 1 g of catalyst, space velocity 3000 h -1 , the deoxidation reaction pressure was 1.8 MPa; the deoxidation reaction gas: the oxygen volume content was 1000 ppm, 1,3-butadiene was 0.65 vol%, acetylene was 0.089 vol%, hydrogen was 12.408 vol%, and the rest was the balance gas N2. The oxygen concentration at the outlet was detected using a micro-oxygen analyzer, and the hydrocarbons were analyzed by on-line gas chromatography. The reaction results for 5 hours are shown in Table 3.

[0059] Table 3

[0060]

[0061] Example 4: Catalyst Mn 1.5 Zn 0.5 Preparation and performance evaluation of Fe4O8 (atomic ratio).

[0062] Prepare Mn 1.5 Zn 0.5 Fe4O8 according to Example 1.

[0063] The prepared Mn 1.5 Zn 0.5 Fe4O8 was loaded into a fixed-bed reactor for reduction treatment. The reduction conditions were as follows: the reduction atmosphere was CO and H2 with a volume ratio of 2:1; the reduction temperature was 300 °C, the reduction time was 5 hours; the heating rate was 2 °C / min, and the reduction reaction pressure was 0.5 MPa. After the reduction treatment, a non-precious metal iron-based deoxidation catalyst was obtained.

[0064] Deoxidation test conditions: A raw gas containing propylene, oxygen, and hydrogen (volume fraction: 98% propylene / 0.2% oxygen / 1.8% hydrogen) was introduced into the above fixed-bed reactor for gas-phase deoxidation reaction. The deoxidation reaction conditions were as follows: the space velocity was 2000 h -1 ⁻¹, the reaction pressure was 1 MPa, and the reaction temperature was 230 °C. At the reaction outlet, the residual oxygen concentration was detected using a micro-oxygen analyzer, and hydrocarbons were analyzed by on-line gas chromatography. The reaction results after 5 hours showed that the loss of propylene was 0.5%, and the residual oxygen concentration was 0.6 ppm.

[0065] Example 5: Catalyst Mn 1.5 Cu 0.5 Preparation and performance evaluation of Fe4O8 (atomic ratio).

[0066] Copper(II) nitrate, manganese(II) nitrate, and iron(III) nitrate were dissolved in 50 mL of deionized water to prepare a precursor solution containing 0.67 mol / L Fe 3+ and certain 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+ , and the molar concentration ratio of Mn 2+ to Cu 2+ was 3:1. Other preparation steps were the same as in Example 1 to obtain Mn 1.5 Cu 0.5Fe4O8.

[0067] The Mn prepared above 1.5 Cu 0.5 Fe4O8 was loaded into a fixed-bed reactor for reduction treatment. The reduction conditions were as follows: the reduction atmosphere was CO and H2, and their volume ratio was 2:1; the reduction temperature was 300 °C, the reduction time was 5 hours; the heating rate was 2 °C / min, and the reduction reaction pressure was 0.5 MPa. After the reduction treatment, a non-noble metal iron-based deoxygenation catalyst was obtained.

[0068] Deoxygenation test conditions: A raw gas containing propylene, oxygen, and hydrogen (volume fraction: 98% propylene / 0.2% oxygen / 1.8% hydrogen) was introduced into the above fixed-bed reactor for gas-phase deoxygenation reaction. The deoxygenation reaction conditions were as follows: the space velocity was 2000 h -1 , the reaction pressure was 1 MPa, and the reaction temperature was 230 °C. At the reaction outlet, the residual oxygen concentration was detected using a micro oxygen analyzer, and the hydrocarbons were analyzed by on-line gas chromatography. The reaction results after 5 hours showed that the loss of propylene was 0.3%, and the residual oxygen concentration was 0.9 ppm.

[0069] Example 6: Preparation and performance evaluation of the catalyst Mn 1.6 Co 0.4 Fe4O8 (atomic ratio).

[0070] Cobalt(II) nitrate, manganese(II) nitrate, and iron(III) nitrate were dissolved in 50 mL of deionized water to prepare a precursor solution containing 0.67 mol / L Fe 3+ and a certain concentration 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+ , and the molar concentration ratio of Mn 2+ to Co 2+ was 4:1. Other preparation steps were the same as in Example 1 to obtain Mn 1.6 Co 0.4 Fe4O8.

[0071] The Mn 1.6 Co 0.4 Fe4O8 prepared above was loaded into a fixed-bed reactor for reduction treatment. The reduction conditions were as follows: the reduction atmosphere was C2H2 and H2, and their volume ratio was 1:1; the reduction temperature was 300 °C, the reduction time was 5 hours; the heating rate was 2 °C / min, and the reduction reaction pressure was 0.5 MPa. After the reduction treatment, a non-noble metal iron-based deoxygenation catalyst was obtained.

[0072] Deoxygenation test conditions: A raw material gas containing propylene, oxygen, and hydrogen (volume fraction: 98% propylene / 0.2% oxygen / 1.8% hydrogen) was introduced into the above fixed-bed reactor for gas-phase deoxygenation reaction. The deoxygenation reaction conditions were as follows: The space velocity was 2000 h -1 , the reaction pressure was 1 MPa, and the reaction temperature was 240 °C. At the reaction outlet, the residual oxygen concentration was detected using a micro oxygen analyzer, and hydrocarbons were analyzed by on-line gas chromatography. The reaction results after 5 hours showed that the loss of propylene was 0.6%, and the residual oxygen concentration was 0.6 ppm.

[0073] Example 7: Preparation and performance evaluation of the catalyst Mn 0.8 ZnCo 0.2 Fe4O8 (atomic ratio).

[0074] Zinc nitrate (II), manganese nitrate (II), cobalt nitrate (II), and iron nitrate (III) were dissolved in 50 mL of deionized water to prepare a precursor solution containing 0.67 mol / L Fe 3+ and a certain concentration of Zn 2+ , CO 2+ , Mn 2+ ions. The total molar concentration of Zn 2+ , Co 2+ and Mn 2+ was fixed at 1 / 2 of the molar concentration of Fe 3+ , and the molar concentration ratio of Zn 2+ , CO 2+ and Mn 2+ was 1:0.2:0.8. Other preparation steps were the same as in Example 1 to obtain Mn 0.8 ZnCo 0.2 Fe4O8.

[0075] The Mn 0.8 ZnCo 0.2 Fe4O8 prepared above was loaded into a fixed-bed reactor for reduction treatment. The reduction conditions were as follows: The reduction atmosphere was CO, the reduction temperature was 300 °C, and the reduction time was 6 hours; the heating rate was 2 °C / min, and the reaction pressure was 0.1 MPa. After the reduction treatment, a non-noble metal iron-based deoxygenation catalyst was obtained.

[0076] Deoxygenation test conditions: A raw material gas containing propylene, oxygen, and hydrogen (volume fraction: 98% propylene / 0.3% oxygen / 1.7% hydrogen) was introduced into the above fixed-bed reactor for gas-phase deoxygenation reaction. The deoxygenation reaction conditions were as follows: The space velocity was 2000 h -1, the reaction pressure was 1 MPa and the reaction temperature was 230 °C. At the reaction outlet, the residual oxygen concentration was detected using a micro oxygen analyzer, and hydrocarbons were analyzed by on-line gas chromatography. The reaction results after 5 hours showed that the loss of propylene was 0.3% and the residual oxygen concentration was 0.9 ppm.

[0077] Example 8: Catalyst Mn 1.8 Zn 0.2 Preparation and performance evaluation of Fe4O8 (atomic ratio).

[0078] Zinc nitrate (II), manganese nitrate (II) and iron nitrate (III) were dissolved in 50 mL of deionized water to prepare a precursor solution containing 0.67 mol / L Fe 3+ and a certain concentration 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+ , and the molar concentration ratio of Mn 2+ to Zn 2+ was 9:1. Other preparation steps were the same as in Example 1 to obtain Mn 1.8 Zn 0.2 Fe4O8.

[0079] The above-prepared Mn 1.8 Zn 0.2 Fe4O8 was first reduced under H2 conditions in a fixed-bed reactor. The heating rate was 5 °C / min, the reduction reaction pressure was 0.1 MPa, the reduction temperature was 400 °C, and the reduction time was 2 h. After the reduction treatment, a non-precious metal iron-based deoxidation catalyst was obtained.

[0080] Deoxidation test conditions: A raw gas containing CO and hydrogen (the volume fractions of CO and hydrogen were approximately 1:1, and the oxygen content was approximately 0.2 vol%) was introduced into the above fixed-bed reactor for a long-term gas-phase deoxidation reaction. The deoxidation reaction conditions were: the space velocity was 2000 h -1 , the reaction pressure was 1 MPa, and the reaction temperature was 250 °C. At the reaction outlet, the residual oxygen concentration was detected using a micro oxygen analyzer, and hydrocarbons were analyzed by on-line gas chromatography. The reaction results are shown in Table 4.

[0081] Table 4

[0082]

[0083] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A non-noble metal deoxidation catalyst, characterized in that, The non-noble metal deoxidation catalyst is obtained by reducing a mixed oxide having a spinel structure; 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 non-noble metal deoxidation catalyst includes at least one active center of a metal element and a metal carbide; In terms of atomic ratio, the chemical formula of the mixed oxide with a spinel structure is Mn x M (2-x) Fe4O8, where 0.1 ≤ x ≤ 1.9, and M is a transition metal including at least one of Zn, Co, Cu, and Ni.

2. The non-noble metal deoxidation catalyst according to claim 1, characterized in that, 0.2≤x≤1.8。 3. The non-noble metal deoxidation catalyst according to claim 1, characterized in that, The hydrocarbon includes at least one of ethylene, propylene, and acetylene.

4. The non-noble metal deoxidation catalyst according to claim 1, characterized in that, The temperature of the reduction is 200~550 °C, the time of the reduction is 2~15 hours, the heating rate of the reduction is 2~10 °C / min, and the pressure of the reduction is 0.1~1 MPa.

5. The preparation method of the non-noble metal deoxidation catalyst according to any one of claims 1 to 4, characterized in that, Including: Prepare a precursor solution containing a Mn source, a transition metal source, and an Fe source; Mix the precursor solution and an alkali solution by a co-dripping method to form a mixed solution; Perform a hydrothermal crystallization reaction on the mixed solution, and after the reaction ends, perform solid-liquid separation, take the solid, wash it, and calcine it to obtain the mixed oxide having a spinel structure; Perform a reduction treatment on the mixed oxide having a spinel structure to obtain the non-noble metal deoxidation catalyst.

6. The preparation method according to claim 5, wherein The Mn source is a Mn salt, and the Mn salt includes 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 iron nitrate and iron 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 atmosphere of the calcination is air; the temperature of the calcination is 400 to 550 °C, the heat preservation time of the calcination is 3 to 6 hours, and the heating rate of the calcination is 2 to 10 °C / min.

8. Application of the non-noble metal deoxidation catalyst according to any one of claims 1 to 4 or the non-noble metal deoxidation catalyst prepared by the preparation method according to any one of claims 5 to 7 in deoxidizing an oxygen-containing gas.

9. A method for deoxidizing an oxygen-containing gas, characterized in that, Including: Use the non-noble metal deoxidation catalyst according to any one of claims 1 to 4 or the non-noble metal deoxidation catalyst prepared by the preparation method according to any one of claims 5 to 7 to remove oxygen in the oxygen-containing gas.

10. The deoxidation method for oxygen-containing gas according to claim 9, characterized in that, The deoxidation reaction conditions of the deoxidation method for the oxygen-containing gas include any one of the following: The deoxidation reaction temperature is 100 to 300 °C; The deoxidation reaction pressure is 0.1 to 3 MPa; The volume content of oxygen in the oxygen-containing gas is not higher than 2%; The volumetric space velocity of the oxygen-containing gas is 1000 to 5000 h -1 .

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