Non-noble metal deoxidation catalyst as well as preparation method and application thereof

Abstract

The invention discloses a non-noble metal deoxidation catalyst as well as a preparation method and application thereof. The non-noble metal deoxidation catalyst is obtained by reducing a mixed oxide with a spinel structure; on the basis of atomic ratio, the chemical expression of the mixed oxide with the spinel structure is MnxM (2-x) Fe4O8, x is more than or equal to 0.1 and less than or equal to 1.9, and M is transition metal and comprises at least one of Zn, Co, Cu and Ni. According to the invention, the deoxidation active components which are uniformly mixed and have different properties can be obtained by regulating and controlling the reduction process, so that the method is suitable for the deoxidation process of various process gases in different scenes. The non-noble metal deoxidation catalyst has the advantages of high activity and selectivity, good heat resistance, low cost and the like, and is suitable for deep deoxidation of systems such as nitrogen, argon and other inert gases, CO gas, low-carbon olefin, gas containing CO and hydrogen and the like, and the residual oxygen content can be as low as less than 1 ppm.

Description

Technical Field

[0001] The 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-precious metal deoxidizers have obvious price advantages and market competitiveness, and currently mainly include manganese-based, copper-based and nickel-based deoxidizers. Patent CN100513367C discloses a MnO / Mn 3 O 4The deoxidation catalyst with active components can effectively remove low concentration oxygen (1~2000 ppm) in gases such as ethylene and propylene, but the catalyst regeneration is frequent. Patent application CN101301611A discloses a non-precious metal copper-based deoxidation catalyst, which is mainly suitable for 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, the main components of which are cerium (Ce) and metal M (M is one or more of Zr, Cu, Fe, Mn, Co, Ni, Zn, S), which is prepared by coprecipitation. Although the catalyst can be supported on honeycomb ceramics and used in an integral form, the amount of rare earth metal cerium is large, resulting in a high catalyst cost. In addition, since multiple active components are loaded by coprecipitation, and the coprecipitation pH value required for each component is different, the uniformity of the active components is difficult to ensure, thereby affecting the performance stability of the catalyst. In addition, Nanhua Company has launched a non-precious metal deoxidation catalyst with nickel as the active center, which can 2 Deoxidation can also be performed chemically at 200 °C and a space velocity of 300-500 h -1 Under the following conditions, nitrogen, argon and hydrocarbon mixed gases can be deoxygenated to 5 ppm, and the deoxygenation capacity can reach 25 mL / g.

[0005] In summary, developing a deoxygenation catalyst with high deoxygenation accuracy and selectivity, good stability, low production cost, and suitable for long-term operation of industrial equipment 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-precious metal deoxidation catalyst and a preparation method and application thereof, aiming to solve the problems of high catalyst cost, complex preparation process, insufficient deoxidation depth and selectivity existing in the prior art. The non-precious metal deoxidation catalyst of the present invention is an efficient iron-based non-precious metal catalyst, wherein the deoxidation active component includes one or more of iron (Fe), manganese (Mn), transition metal (M) and its 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-precious metal deoxidation catalyst of the present invention has the advantages of high activity and selectivity, high heat resistance temperature, good heat resistance (for example, it can be efficiently deoxidized 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 deep deoxidation of inert gases such as nitrogen and argon, CO gas, low-carbon olefins (C2~C4 olefins, including ethylene, propylene, butene, etc.), and gases containing CO and hydrogen (such as synthesis gas), wherein the residual oxygen content can be as low as less than 1 ppm.

[0007] The specific technical solutions are as follows: In a first aspect, the present invention provides a non-precious metal deoxidation catalyst, wherein 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, M is a transition metal, including at least one of zinc (Zn), cobalt (Co), copper (Cu), and nickel (Ni), and preferably includes Zn, or Zn and Co. As one example, M is Zn. As another example, M is Zn and Co, and further, the molar ratio of Zn to Co can be 4 to 6:1, such as 5:1.

[0008] 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, thereby achieving synergistic effects; further by doping with different transition metal elements, the distribution of metal cations in the crystal structure, oxygen lattice energy, electronic state density distribution and other microscopic characteristics can be further regulated, thereby affecting the reducibility, redox capability and properties and density of catalytic sites on the catalyst surface, thereby regulating the selective and efficient activation of trace oxygen in different application scenarios.

[0009] In some preferred examples, the non-precious metal deoxygenation catalyst, 0.2≤x≤1.8, for example, x can be 0.5, 0.8, 1, 1.5, 1.6, 1.7, etc.

[0010] Transition metal elements such as Zn, Co, Cu, and Ni have different 3d electronic configurations and energy level structures, and exhibit different oxygen coordination environments and electron migration characteristics in the lattice. When Zn is used as the main transition metal dopant, due to the 2+ Ions have full 3d 10 The electronic structure of Zn tends to occupy the tetrahedral (A) site in the spinel lattice, which helps to adjust the lattice oxygen stability and promote the electronic structure regulation of the adjacent octahedral (B) Fe and Mn ions, thereby improving the reduction characteristics of the overall crystal. In addition, the introduction of Zn can effectively reduce the oxygen ion and Fe 3+ / Mn 3+ The bonding energy between them promotes the activation and desorption of lattice oxygen, thereby improving the oxygen migration rate and catalytic reaction activity of the catalyst under deoxidation reaction conditions. 2+ / Co3+ The presence of mixed valence states introduces abundant oxygen vacancies and oxygen defect states, and further optimizes the electronic structure, making the catalyst exhibit higher reducibility and oxygen transfer activity. Selecting a suitable intermediate ratio range (0.2≤x≤1.8) can achieve the optimal balance between oxygen transfer and reducibility.

[0011] The non-precious metal deoxidation catalyst can use a reducing gas to reduce the mixed oxide with a spinel structure. By reducing the catalyst with different gases, the active phase type and composition of the deoxidation catalyst can be precisely controlled, and then the adsorption and activity mode of oxygen can be adjusted, so that it is suitable for deep deoxidation of various process gases in different scenarios. Furthermore, the reducing gas may include at least one of hydrogen, carbon monoxide, and hydrocarbons. Furthermore, the hydrocarbon may include at least one of ethylene, propylene, and acetylene.

[0012] In some embodiments, the reducing gas is hydrogen, and the obtained non-precious metal deoxygenation catalyst is particularly suitable for deep deoxygenation of systems such as nitrogen, argon and other inert gases, CO gas and gases containing both CO and hydrogen (such as synthesis gas).

[0013] 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-precious metal deoxygenation catalyst is particularly suitable for deep deoxygenation of low-carbon olefins (C2~C4 olefins, including ethylene, propylene, butene, etc.), and can show extremely high deoxygenation efficiency and deoxygenation selectivity, significantly reducing olefin losses. Furthermore, in the mixture of at least one of carbon monoxide and hydrocarbons and hydrogen, the ratio of the volume of at least one of carbon monoxide and hydrocarbons to the volume of hydrogen can be 1~2:1, etc.

[0014] The non-precious metal deoxidation catalyst, 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 reduction heating rate can be 2~10°C / min, such as 5°C / min, etc., the reduction pressure can be 0.1~1 MPa, such as 0.5 MPa, etc.

[0015] In a second aspect, the present invention provides a method for preparing the non-precious metal deoxidation catalyst according to the first aspect, comprising: 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.

[0016] The mixed oxide precursor with a spinel structure prepared by the preparation method of the present invention has the characteristics of large specific surface area, uniform particle size, etc.; different elements are mixed uniformly, and the method is relatively simple in process, highly operable, and easy to scale up industrially.

[0017] The Mn source may be a Mn salt. Further, the Mn salt may include at least one of manganese acetate and manganese nitrate.

[0018] The transition metal source may be a transition metal salt. Further, the transition metal salt may include at least one of nitrates, acetates, and chlorides of the transition metal.

[0019] The Fe source may be an Fe salt. Further, the Fe salt may include at least one of ferric nitrate and ferric chloride.

[0020] The alkali solution may be a precipitant solution. Further, the precipitant may include sodium hydroxide (NaOH), sodium carbonate (Na 2 CO 3 ), at least one of urea, aqueous ammonia, tetramethylammonium hydroxide, and tetrapropylammonium hydroxide.

[0021] The pH of the mixed solution may be 9-11, further 9-10, preferably 10, which is beneficial to improving the deoxidation performance of the catalyst.

[0022] The temperature of the hydrothermal crystallization reaction may be 30 to 150°C, preferably 30 to 60°C, such as 50°C.

[0023] The hydrothermal crystallization reaction time may be 2 to 10 hours.

[0024] The calcination atmosphere is air.

[0025] The calcination temperature may be 400 to 550° C., such as 450° C.

[0026] The calcination holding time may be 3 to 6 hours, such as 4 hours.

[0027] The heating rate of the calcination may be 2 to 10° C. / min, for example 5° C. / min.

[0028] In a third aspect, the present invention provides use of the non-precious metal deoxygenation catalyst according to the first aspect or the non-precious metal deoxygenation catalyst prepared according to the preparation method of the second aspect in deoxygenation of oxygen-containing gas.

[0029] In a fourth aspect, the present invention provides a method for deoxygenating an oxygen-containing gas, comprising: removing oxygen from the oxygen-containing gas using the non-precious metal deoxygenation catalyst described in the first aspect or the non-precious metal deoxygenation catalyst prepared by the preparation method described in the second aspect.

[0030] The deoxygenation reaction conditions of the application described in the third aspect and the deoxygenation method for oxygen-containing gas described in the fourth aspect may include any of the following: The deoxygenation reaction temperature is 100 to 300° C., such as 130° C., 170° C., 200° C., 220° C., 230° C., 240° C., 250° C., etc.; The deoxygenation reaction pressure is 0.1 to 3 MPa, such as 1 MPa, 1.8 MPa, etc.; The volume content of oxygen in the oxygen-containing gas is not higher than 2%, for example, 1000 ppm, 0.2%, 0.3%, etc.; The volume space velocity of the oxygen-containing gas is 1000 to 5000 h -1 , e.g. 2000 h -1 , 3000 h -1 wait.

[0031] In the application described in the third aspect and the deoxygenation method for oxygen-containing gas described in the fourth aspect, the oxygen-containing gas can be an inert gas such as nitrogen, argon, CO gas, low-carbon olefins (C2~C4 olefins, including ethylene, propylene, butene, etc.), a gas containing both CO and hydrogen (such as synthesis gas), etc.

[0032] Compared with the prior art, the present invention has the following beneficial effects: 1. Non-precious metal active center, low cost: The present invention selects manganese, iron and transition metals as active components, considering that these metal compounds are cheap and widely available; and the catalyst preparation method is simple, suitable for large-scale industrial production, and has good economy and operability.

[0033] 2. High catalytic activity, low removal depth and wide application range: The iron-manganese spinel catalyst prepared by the present invention has a 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 metal elements, metal oxides, metal carbides, etc., which are suitable for deep deoxygenation of multiple gas systems in different scenarios. For example, through hydrogen reduction, metal element active centers can be formed, thereby achieving deep removal of trace oxygen in synthesis gas and inert gases (for example, including one or more combinations of nitrogen and rare gases), and the deoxygenation depth can be as low as less than 0.5ppm; by using one or more of carbon monoxide and hydrocarbons, or a mixture of at least one of carbon monoxide and hydrocarbons and hydrogen for reduction and carbonization, metal carbide active centers can be formed, which are suitable for deep removal of trace oxygen in light olefins, and 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

[0034] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0035] Example 1: Catalyst Mn 1.5 Zn 0.5 Fe 4 O 8 (atomic ratio) preparation and performance evaluation.

[0036] Dissolve zinc (II) nitrate, manganese (II) nitrate, and iron (III) nitrate in 50 mL of deionized water to prepare a solution containing 0.67 mol / L Fe 3+ and a certain concentration of Zn 2+ and Mn 2+ ion precursor solution. Zn 2+ and Mn 2+ The total molar concentration is fixed as Fe 3+ 1 / 2 of the molar concentration, Mn 2+ With Zn 2+ The molar concentration ratio is 3:1. The precursor solution and 2 mol / L NaOH solution were mixed by co-drop 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. The precipitate was then rinsed with ultrapure water three times. Next, the solid product was dried at 100°C overnight 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 Fe 4 O 8 , with a specific surface area of ​​about 40 m 2 g -1 .

[0037] The Mn prepared above 1.5Zn 0.5 Fe 4 O 8 First, in H 2 The reduction was carried out under the following conditions: the heating rate was 5 °C / min, the reduction reaction pressure was 0.1 MPa, the reduction temperature was 400 °C, the reduction time was 2 h, the deoxygenation reaction temperature was shown in Table 1, fixed bed, 1 g catalyst, space velocity 3000 h -1 , deoxygenation reaction pressure 1.8 MPa; deoxygenation reaction gas: oxygen volume content 1000 ppm, 1,3-butadiene 0.65vol%, acetylene 0.089vol%, hydrogen 12.408vol%, the rest is balance gas N 2 The oxygen concentration at the outlet was detected using a trace oxygen analyzer, and hydrocarbons were analyzed using online gas chromatography. The results of the 5-hour reaction are shown in Table 1.

[0038] Table 1

[0039] Example 2: Catalyst Mn 1.5 Ni 0.5 Fe 4 O 8 (atomic ratio) preparation and performance evaluation.

[0040] Dissolve nickel (II) nitrate, manganese (II) nitrate, and iron (III) nitrate in 50 mL of deionized water to prepare a solution containing 0.67 mol / L Fe 3+ and a certain concentration of Ni 2+ and Mn 2+ Ion precursor solution. Ni 2+ and Mn 2+ The total molar concentration is fixed as Fe 3+ 1 / 2 of the molar concentration, Mn 2+ with Ni 2+ The molar concentration ratio is 3:1. The other preparation steps are the same as in Example 1 to obtain Mn 1.5 Ni 0.5 Fe 4 O 8 .

[0041] The Mn prepared above 1.5 Ni 0.5 Fe 4 O 8 First, in H 2 The reduction was carried out under the following conditions: the heating rate was 5 °C / min, the reduction reaction pressure was 0.1 MPa, the reduction temperature was 400 °C, the reduction time was 2 h, the deoxygenation reaction temperature was shown in Table 2, fixed bed, 1 g catalyst, space velocity 3000 h -1, deoxygenation reaction pressure 1.8 MPa; deoxygenation reaction gas: oxygen volume content 1000 ppm, 1,3-butadiene 0.65vol%, acetylene 0.089vol%, hydrogen 12.408vol%, the rest is balance gas N 2 The oxygen concentration at the outlet was detected using a trace oxygen analyzer, and hydrocarbons were analyzed using online gas chromatography. The results of the 5-hour reaction are shown in Table 2.

[0042] Table 2

[0043] Example 3: Catalyst Mn 1.7 Co 0.3 Fe 4 O 8 (atomic ratio) preparation and performance evaluation.

[0044] Dissolve cobalt (II) nitrate, manganese (II) nitrate, and iron (III) nitrate in 50 mL of deionized water to prepare a solution containing 0.67 mol / L Fe 3+ and a certain concentration of Co 2+ and Mn 2+ ion precursor solution. Co 2+ and Mn 2+ The total molar concentration is fixed as Fe 3+ 1 / 2 of the molar concentration, Mn 2+ With Co 2+ The molar concentration ratio is 17:3. The other preparation steps are the same as in Example 1 to obtain Mn 1.7 Co 0.3 Fe 4 O 8 .

[0045] The Mn prepared above 1.7 Co 0.3 Fe 4 O 8 First, in H 2 The reduction was carried out under the following conditions: the heating rate was 5 °C / min, the reduction pressure was 0.1 MPa, the reduction temperature was 400 °C, the reduction time was 2 h, the deoxygenation reaction temperature was shown in Table 3, fixed bed, 1 g catalyst, space velocity 3000 h -1 , deoxygenation reaction pressure 1.8 MPa; deoxygenation reaction gas: oxygen volume content 1000 ppm, 1,3-butadiene 0.65vol%, acetylene 0.089vol%, hydrogen 12.408vol%, the rest is balance gas N 2 The oxygen concentration at the outlet was detected using a trace oxygen analyzer, and hydrocarbons were analyzed using online gas chromatography. The results of the 5-hour reaction are shown in Table 3.

[0046] Table 3

[0047] Example 4: Catalyst Mn 1.5 Zn 0.5 Fe 4 O 8 (atomic ratio) preparation and performance evaluation.

[0048] Prepare Mn according to Example 1 1.5 Zn 0.5 Fe 4 O 8 .

[0049] The Mn prepared above 1.5 Zn 0.5 Fe 4 O 8 The mixture is loaded into a fixed bed reactor for reduction treatment. The reduction conditions are: the reducing atmosphere is CO and H 2 , the volume ratio is 2:1; the reduction temperature is 300℃, the reduction time is 5 hours; the heating rate is 2℃ / min, and the reduction reaction pressure is 0.5 MPa. After the reduction treatment, a non-precious metal iron-based deoxidation catalyst is obtained.

[0050] Deoxygenation test conditions: Feed 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. Deoxygenation reaction conditions: space velocity of 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 by a trace oxygen analyzer, and the hydrocarbons were analyzed by online gas chromatography. The 5-hour reaction results showed that the loss of propylene was 0.5% and the residual oxygen concentration was 0.6 ppm.

[0051] Example 5: Catalyst Mn 1.5 Cu 0.5 Fe 4 O 8 (atomic ratio) preparation and performance evaluation.

[0052] Dissolve copper (II) nitrate, manganese (II) nitrate, and iron (III) nitrate in 50 mL of deionized water to prepare a solution containing 0.67 mol / L Fe 3+ and a certain concentration of Cu 2+ and Mn 2+ Ion precursor solution. Cu 2+ and Mn 2+ The total molar concentration is fixed as Fe 3+ 1 / 2 of the molar concentration, Mn 2+ With Cu2+ The molar concentration ratio is 3:1. The other preparation steps are the same as in Example 1 to obtain Mn 1.5 Cu 0.5 Fe 4 O 8 .

[0053] The Mn prepared above 1.5 Cu 0.5 Fe 4 O 8 The mixture is loaded into a fixed bed reactor for reduction treatment. The reduction conditions are: the reducing atmosphere is CO and H 2 , the volume ratio is 2:1; the reduction temperature is 300℃, the reduction time is 5 hours; the heating rate is 2℃ / min, and the reduction reaction pressure is 0.5 MPa. After the reduction treatment, a non-precious metal iron-based deoxidation catalyst is obtained.

[0054] Deoxygenation test conditions: Feed 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. Deoxygenation reaction conditions: space velocity of 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 by a trace oxygen analyzer, and the hydrocarbons were analyzed by online gas chromatography. The 5-hour reaction results showed that the loss of propylene was 0.3% and the residual oxygen concentration was 0.9 ppm.

[0055] Example 6: Catalyst Mn 1.6 Co 0.4 Fe 4 O 8 (atomic ratio) preparation and performance evaluation.

[0056] Dissolve cobalt (II) nitrate, manganese (II) nitrate, and iron (III) nitrate in 50 mL of deionized water to prepare a solution containing 0.67 mol / L Fe 3+ and a certain concentration of Co 2+ and Mn 2+ ion precursor solution. Co 2+ and Mn 2+ The total molar concentration is fixed as Fe 3+ 1 / 2 of the molar concentration, Mn 2+ With Co 2+ The molar concentration ratio is 4:1. The other preparation steps are the same as in Example 1 to obtain Mn 1.6 Co 0.4 Fe 4 O 8 .

[0057] The Mn prepared above1.6 Co 0.4 Fe 4 O 8 The mixture is loaded into a fixed bed reactor for reduction treatment. The reduction conditions are: the reducing atmosphere is C 2 H 2 and H 2 , the volume ratio is 1:1; the reduction temperature is 300℃, the reduction time is 5 hours; the heating rate is 2℃ / min, and the reduction reaction pressure is 0.5 MPa. After the reduction treatment, a non-precious metal iron-based deoxidation catalyst is obtained.

[0058] Deoxygenation test conditions: Feed 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. Deoxygenation reaction conditions: space velocity of 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 by a trace oxygen analyzer, and hydrocarbons were analyzed by online gas chromatography. The 5-hour reaction results showed that the loss of propylene was 0.6% and the residual oxygen concentration was 0.6 ppm.

[0059] Example 7: Catalyst Mn 0.8 ZnCo 0.2 Fe 4 O 8 (atomic ratio) preparation and performance evaluation.

[0060] Dissolve zinc (II) nitrate, manganese (II) nitrate, cobalt (II) nitrate, and iron (III) nitrate in 50 mL of deionized water to prepare a solution containing 0.67 mol / L Fe 3+ and a certain concentration of Zn 2+ , CO 2+ , Mn 2+ ion precursor solution. Zn 2+ 、Co 2+ and Mn 2+ The total molar concentration is fixed as Fe 3+ 1 / 2 of the molar concentration, Zn 2+ , CO 2+ and Mn 2+ The molar concentration ratio of Mn is 1:0.2:0.8. The other preparation steps are the same as in Example 1 to obtain Mn 0.8 ZnCo 0.2 Fe 4 O 8 .

[0061] The Mn prepared above 0.8 ZnCo 0.2 Fe4 O 8 The catalyst was loaded into a fixed bed reactor for reduction treatment. The reduction conditions were as follows: the reducing atmosphere was CO, the reducing temperature was 300°C, the reducing 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-precious metal iron-based deoxidation catalyst was obtained.

[0062] Deoxygenation test conditions: Feed 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. Deoxygenation reaction conditions: space velocity of 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 by a trace oxygen analyzer, and the hydrocarbons were analyzed by online gas chromatography. The 5-hour reaction results showed that the loss of propylene was 0.3% and the residual oxygen concentration was 0.9 ppm.

[0063] Example 8: Catalyst Mn 1.8 Zn 0.2 Fe 4 O 8 (atomic ratio) preparation and performance evaluation.

[0064] Dissolve zinc (II) nitrate, manganese (II) nitrate, and iron (III) nitrate in 50 mL of deionized water to prepare a solution containing 0.67 mol / L Fe 3+ and a certain concentration of Zn 2+ and Mn 2+ ion precursor solution. Zn 2+ and Mn 2+ The total molar concentration is fixed as Fe 3+ 1 / 2 of the molar concentration, Mn 2+ With Zn 2+ The molar concentration ratio is 9:1. The other preparation steps are the same as in Example 1 to obtain Mn 1.8 Zn 0.2 Fe 4 O 8 .

[0065] The Mn prepared above 1.8 Zn 0.2 Fe 4 O 8 First, in a fixed bed reactor, 2 The reduction was carried out under the following 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. After the reduction treatment, a non-precious metal iron-based deoxidation catalyst was obtained.

[0066] Deoxygenation test conditions: The raw gas containing CO and hydrogen (the volume fraction of CO and hydrogen is about 1:1, and the oxygen content is about 0.2 vol%) is introduced into the above fixed bed reactor for a long-term gas phase deoxygenation reaction. The deoxygenation reaction conditions are: the space velocity is 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 by a trace oxygen analyzer, and the hydrocarbons were analyzed by online gas chromatography. The reaction results are shown in Table 4.

[0067] Table 4

[0068] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A non-precious metal deoxidation catalyst, characterized in that: The non-noble 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) Fe4O8, 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: Reducing the mixed oxide having a spinel structure 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: include: 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 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 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: include: The oxygen in the oxygen-containing gas is removed using the non-precious metal deoxidation catalyst described in any one of claims 1 to 4 or the non-precious metal deoxidation catalyst prepared by the preparation method described in any one of claims 5 to 7.

10. The method for deoxygenating an 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 .

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