A method for removing carbon monoxide from hydrogen-rich gas

Abstract

This application discloses a method for removing carbon monoxide from hydrogen-rich gas, comprising the following steps: feeding the raw gas into a reactor and contacting it with a catalyst, reacting at a reaction temperature of 50-300℃ and a pressure of 1-5MPa. The catalyst is a Fe-N-C / ZrO₂ catalyst, the preparation method of which includes the following steps: dissolving ZrOCl₂·8H₂O in an ethanol / water mixed solvent, adjusting the pH to 9-10 to generate a sol, adding a template agent to obtain a mesoporous ZrO₂ support; dispersing the mesoporous ZrO₂ support in a polyaniline solution, adding FeCl₃, stirring, filtering, drying the filter cake to obtain a precursor powder; placing the precursor powder in a reactor and carbonizing it at 700-900℃ for 1-3 hours under an inert gas to obtain the Fe-N-C / ZrO₂ catalyst. This method has excellent carbon monoxide removal effect and produces few side reactions.

Description

Technical Field

[0001] This application relates to the field of carbon monoxide removal technology, and in particular to a method for removing carbon monoxide from hydrogen-rich gas. Background Technology

[0002] Carbon monoxide (CO) is highly toxic, can bind to hemoglobin and cause oxygen deficiency in the human body, and also poses a risk of corrosion to industrial equipment, especially accelerating metal aging in high-temperature and high-pressure environments. To address CO pollution, existing technologies mainly fall into two categories: chemical conversion and physical separation. Chemical conversion methods selectively oxidize CO to CO2 through catalytic oxidation, or generate CH4 through methanation, while water-gas shift reactions adjust the CO / H2 ratio to optimize gas composition. Physical separation methods utilize the porous structure of adsorbent materials to selectively adsorb CO.

[0003] When applied to hydrogen-rich gases, there are problems of insufficient removal efficiency and difficulty in controlling side reactions. During catalytic oxidation, the catalyst is easily poisoned and deactivated by impurities such as sulfur and chlorine, resulting in insufficient removal efficiency. In addition, side reactions are easily triggered during the reaction, which consume H2 and produce CH4 impurities, reduce the purity of hydrogen, and cause product contamination. Summary of the Invention

[0004] To address the issues of poor removal efficiency and uncontrollable side reactions when removing carbon monoxide from hydrogen-rich gases, a method for removing carbon monoxide from hydrogen-rich gases is provided.

[0005] The above-mentioned objective of this invention is achieved through the following technical solutions:

[0006] A method for removing carbon monoxide from hydrogen-rich gas, comprising the following steps: contacting the feed gas with a catalyst, and reacting at a reaction temperature of 50-300℃ and a pressure of 1-5MPa, wherein the catalyst is a Fe-NC / ZrO2 catalyst, and its preparation method comprises the following steps:

[0007] S1: Dissolve ZrOCl2·8H2O in an ethanol / water mixed solvent, add a pH adjuster to adjust the pH to 9-10 to generate a sol, add a template agent to obtain a mesoporous ZrO2 support;

[0008] S2: Disperse the mesoporous ZrO2 support in a polyaniline solution, add FeCl3, stir, filter, and dry the filter cake to obtain the precursor powder;

[0009] S3: Place the precursor powder in a reactor and carbonize it at 700-900℃ for 1-3 hours under an inert gas to obtain the Fe-NC / ZrO2 catalyst.

[0010] By adopting the above technical solution, the mesoporous ZrO2 support of the Fe-NC / ZrO2 catalyst has a three-dimensional network structure with high specific surface area and concentrated pore size distribution, providing anchoring points for the dispersion of active components. Its mesoporous channels are more conducive to the rapid diffusion of reactants and products, reducing internal diffusion resistance. Its active centers are Fe-N in the form of atomic-level or nanoclusters. X The site has relatively weak adsorption and activation capacity for hydrogen, making it less prone to side reactions. It also possesses high thermal stability and mechanical strength, making it less susceptible to sintering, loss, and phase transitions. This results in a longer active period and superior performance. Furthermore, the NC layer itself exhibits good chemical inertness and conductivity, which helps reduce deep oxidation of Fe or adverse reactions with impurities in the reaction atmosphere. In the preparation of the Fe-NC / ZrO2 catalyst, ZrOCl2·8H2O is used as a precursor, hydrolyzed in an ethanol / water mixed solvent. Adjusting the pH to alkaline (9-10) promotes the formation of Zr(OH)4 sol by zirconium ions and further... The one-step polycondensation process, with the addition of a template agent, facilitates the formation of a mesoporous zirconia support with a regular morphology and high specific surface area. Polyaniline, as a nitrogen-rich polymer, can strongly adsorb onto the surface of the mesoporous ZrO2 support through its amino and imine functional groups and complex Fe³⁺ ions, forming a precursor with ZrO2 as the backbone and polyaniline-Fe complex uniformly encapsulated. The high-temperature carbonization process is carried out under an inert atmosphere, where polyaniline undergoes pyrolysis and carbonization to generate a nitrogen-doped carbon layer (NC). Simultaneously, the complexed Fe³⁺ is reduced and coordinated with nitrogen to form Fe-N in atomically dispersed or nanocluster form. X The active sites also anchor Fe, which helps reduce Fe migration during the reaction. In summary, this preparation method achieves high activity and high stability of the catalyst, and the catalyst achieves efficient and selective removal of carbon monoxide.

[0011] Preferably, the gas space velocity of the raw material is 1000-10000 h⁻¹.

[0012] By adopting the above technical solution, when the space velocity is maintained in the range of 1000–10000 h⁻¹, the residence time of the gas in the catalyst bed is controlled within a reasonable range. This helps to reduce the problem of excessively high space velocity, short contact time between reactant molecules and active sites, and CO molecules leaving the reactor before being fully adsorbed, activated and converted, which leads to a decrease in conversion rate. At the same time, it helps to reduce the problem of catalyst failure or aggravated side reactions caused by excessively low space velocity, which cannot be carried away by the heat of reaction in time due to local overheating.

[0013] Preferably, the volume fraction of carbon monoxide in the feed gas is 0.1-10 vol.

[0014] By adopting the above technical solution, within this range, Fe-N XThe active sites have a high adsorption affinity for CO, which can effectively capture and convert CO. The catalyst has high utilization of active sites and can operate stably and efficiently.

[0015] Preferably, the template agent in step S1 is P123 template agent.

[0016] By adopting the above technical solution, P123, as a triblock copolymer, can self-assemble into micelles in solution through its hydrophilic-hydrophobic block structure, guiding the ZrO2 precursor to hydrolyze and condense around it. After subsequent calcination to remove the template, a highly ordered mesoporous structure with uniform pore size is replicated in ZrO2. The mesoporous ZrO2 support prepared using P123 has better pore connectivity and pore size distribution than the random pores obtained using ordinary precipitants, which is beneficial to improving the volumetric efficiency of the catalyst and achieving higher processing capacity and faster reaction rate on the same volume of catalyst.

[0017] Preferably, Y(NO3)3·6H2O is added in step S1.

[0018] By adopting the above technical solution, Y(NO3)3·6H2O is introduced to modify the ZrO2 support with yttrium doping. The ionic radius of yttrium ions (Y³⁺) is similar to that of zirconium ions (ZrO2). 4 The valence state of Y³⁺ is similar to that of ZrO₂, and it can be doped into the ZrO₂ lattice. 4 To maintain electroneutrality, oxygen vacancies are introduced into the crystal lattice. These vacancies themselves act as active sites, adsorbing and activating oxygen molecules in the gas phase, making them more readily dissociated into reactive oxygen species. Furthermore, oxygen vacancies enhance the oxygen storage capacity and surface oxygen mobility of the ZrO2 support. In the CO oxidation reaction, reactive oxygen species on the support surface can migrate to neighboring Fe-N bonds. x As an active center, Y participates in the oxidation process of CO. Y doping can also inhibit the transformation of ZrO2 from the metastable tetragonal phase to the monoclinic phase, improve the thermal stability and structural stability of the support at the reaction temperature, and enhance the catalytic effect of the catalyst.

[0019] Preferably, the molar ratio of Y to Zr is 1:(5-20).

[0020] By adopting the above technical solution, at this ratio, it is beneficial to generate a sufficiently high concentration of oxygen vacancies for activating oxygen and promoting oxygen migration, while maintaining the integrity of the ZrO2 host structure, the unobstructedness of the mesoporous structure, and the high specific surface area, thereby improving the final catalyst effect.

[0021] Preferably, in step S1, cerium ammonium nitrate is also added, and the amount added is 0.5-1% of the mass of ZrOCl2·8H2O.

[0022] By adopting the above technical solution and adding cerium ammonium nitrate to introduce cerium, the cerium element has Ce³⁺ / Ce 4+ Reversible redox pairs exhibit excellent oxygen storage and release capabilities. In the catalyst, cerium species are highly dispersed in oxide form on the surface or in the lattice of the ZrO2 support, acting as an oxygen buffer. When the local oxygen concentration is high, Ce³⁺ can be oxidized to Ce. 4+ Excess oxygen; when the local oxygen supply is insufficient, Ce 4+ The release of active oxygen is beneficial for the continuous and efficient catalytic reaction. Furthermore, cerium oxide can interact with iron, further stabilizing the active iron centers, inhibiting their aggregation or loss during the reaction process, and enhancing the catalyst's effectiveness.

[0023] Preferably, the pH adjuster in step S1 is an aqueous solution of tetramethylammonium hydroxide.

[0024] By adopting the above technical solution, tetramethylammonium hydroxide provides a high concentration of OH⁻ and quaternary ammonium cations. Its OH⁻ can rapidly and uniformly increase the pH of the solution, promoting the rapid and uniform precipitation of zirconium ion species generated by the hydrolysis of ZrOCl2. This is conducive to the formation of primary zirconium hydroxide particles with small particle size and narrow distribution. The tetramethylammonium cations can be adsorbed on the surface of the initially formed particles, inhibiting excessive particle growth and hard agglomeration through steric hindrance effect. This helps to ultimately obtain a mesoporous ZrO2 support with high specific surface area, more concentrated pore size distribution, and more optimized pore structure, so that the active sites of the final catalyst are more fully exposed, thereby improving the performance of the catalyst.

[0025] In summary, this application has at least the following beneficial effects:

[0026] (1) The Fe-NC / ZrO2 catalyst mesoporous support has a high specific surface area three-dimensional network structure, which promotes the dispersion of active components and rapid diffusion of substances. X It exhibits weak hydrogen adsorption at specific sites, few side reactions, and combines high thermal stability with chemical inertness.

[0027] (2) Achieve high activity and high stability of catalyst, and remove carbon monoxide efficiently and selectively to meet the requirements of industrial applications for catalytic performance and stability. Detailed Implementation

[0028] raw material

[0029] P123 template agent, specifically Pluronic P123 template agent with a molecular weight of 5800, was purchased from Nanjing Ruichuang Chemical Technology Co., Ltd.

[0030] Hexadecyltrimethylammonium bromide, 99 wt% purity, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0031] N-methylpyrrolidone, cerium ammonium nitrate, zirconium oxychloride octahydrate (ZrOCl2·8H2O), tetramethylammonium hydroxide, ferric chloride (FeCl3), polyaniline, 30wt% ammonia, and ethanol are all commercially available.

[0032] Preparation Example 1

[0033] A Fe-NC / ZrO2 catalyst is prepared as follows:

[0034] S1: Dissolve 20g of ZrOCl2·8H2O, 2.38g of Y(NO3)3·6H2O, and 0.16g of cerium ammonium nitrate in 400mL of ethanol / water mixed solvent (volume ratio 1:1). Stir at 100 rpm for 5min to obtain zirconium oxychloride solution. Add 8g of Pluronic P123 template agent to 200mL of ethanol, add zirconium oxychloride solution, stir at 100 rpm for 2h, adjust pH to 9.5 with 25wt% tetramethylammonium hydroxide aqueous solution, and stir at 300... Stir at rpm for 6 hours, let stand for 24 hours to obtain an emulsion sol. Transfer the emulsion sol to a hydrothermal reactor and hydrothermally treat at 100℃ for 24 hours. Cool to room temperature (25℃), filter to obtain a filter cake. Wash the filter cake alternately with ethanol and deionized water until the solution after washing is free of chloride ions. Place it in a vacuum drying oven and dry at -0.05MPa vacuum and 80℃ for 12 hours. Place the dried product in a muffle furnace and calcine at 400℃ at a rate of 2℃ / min for 4 hours to obtain a mesoporous ZrO2 support.

[0035] S2: Add 5g of polyaniline to 500mL of N-methylpyrrolidone and sonicate at 300W for 1h to obtain a polyaniline dispersion. Add mesoporous ZrO2 support to the polyaniline dispersion and stir at 300 rpm for 6h. Dissolve 2g of FeCl3 in 50mL of ethanol to obtain a ferric chloride solution. Add the polyaniline dispersion to the ferric chloride solution at 10mL / s while stirring at 100 rpm. After the addition is complete, stir at 100 rpm for 12h to obtain a mixture. Filter the mixture to obtain a filter cake. Wash the filter cake three times with ethanol. Then place the filter cake in a vacuum drying oven and dry it at -0.05MPa and 60℃ for 24h to obtain the precursor powder.

[0036] S3: Place the precursor powder in a tube furnace, introduce argon gas at 100 sccm for 30 min, raise the temperature to 800℃ at a rate of 5℃ / min, maintain the temperature at 800℃ for 2 h, stop heating, and allow it to cool naturally to 200℃ to obtain the Fe-NC / ZrO2 catalyst.

[0037] Preparation Example 2

[0038] A Fe-NC / ZrO2 catalyst, which differs from Preparation Example 1 in that: hexadecyltrimethylammonium bromide is used in place of the Pluronic P123 template agent by mass; the rest is the same as Preparation Example 1.

[0039] Preparation Example 3

[0040] A Fe-NC / ZrO2 catalyst, which differs from Preparation Example 1 in that Y(NO3)3 is not added in step S1; the rest of the steps are the same as Preparation Example 1.

[0041] Preparation Example 4

[0042] A Fe-NC / ZrO2 catalyst, which differs from Preparation Example 1 in that: 4.75 g of Y(NO3)3 is added in step S1; the rest is the same as Preparation Example 1.

[0043] Preparation Example 5

[0044] A Fe-NC / ZrO2 catalyst, which differs from Preparation Example 1 in that: 1.19 g of Y(NO3)3 is added in step S1; the rest is the same as Preparation Example 1.

[0045] Preparation Example 6

[0046] A Fe-NC / ZrO2 catalyst, which differs from Preparation Example 1 in that: 5g of Y(NO3)3 is added in step S1; the rest is the same as Preparation Example 1.

[0047] Preparation Example 7

[0048] A Fe-NC / ZrO2 catalyst, which differs from Preparation Example 1 in that: 1g of Y(NO3)3 is added in step S1; the rest is the same as Preparation Example 1.

[0049] Preparation Example 8

[0050] A Fe-NC / ZrO2 catalyst, which differs from Preparation Example 1 in that: cerium ammonium nitrate is not added in step S1; the rest of the steps are the same as Preparation Example 1.

[0051] Preparation Example 9

[0052] A Fe-NC / ZrO2 catalyst, which differs from Preparation Example 1 in that: in step S1, 30 wt% ammonia water is used to adjust the pH to 9.5; the rest of the steps are the same as Preparation Example 1.

[0053] Preparation Example 10

[0054] A Fe-NC / ZrO2 catalyst differs from Preparation Example 1 in that: 0.1 g of cerium ammonium nitrate is added in step S1, and the temperature is raised to 700°C at a rate of 5°C / min in step S3 and maintained at 700°C for 3 hours; the rest of the process is the same as in Preparation Example 1.

[0055] Preparation Example 11

[0056] A Fe-NC / ZrO2 catalyst differs from Preparation Example 1 in that: 0.2 g of cerium ammonium nitrate is added in step S1, and the temperature is raised to 900°C at a rate of 5°C / min in step S3 and maintained at 700°C for 1 hour; the rest of the process is the same as in Preparation Example 1.

[0057] Example 1

[0058] A method for removing carbon monoxide from hydrogen-rich gas includes the following steps:

[0059] 1 ml of Fe-NC / ZrO2 catalyst, derived from Preparation Example 1, was packed into a reactor with an inner diameter of 8 mm to a height of 30 mm. The feed gas was introduced into the reactor at a pressure of 3 MPa and a space velocity of 5000 h⁻¹. -1 The reaction is carried out at a temperature of 200℃. The raw material gas consists of carbon monoxide, oxygen and hydrogen, with carbon monoxide having a volume fraction of 5 vol% and oxygen having a volume fraction of 4 vol%.

[0060] Comparative Example 1

[0061] A method for removing carbon monoxide from hydrogen-rich gas differs from Example 1 in that: an equal volume of a noble metal catalyst is used instead of the Fe-NC / ZrO2 catalyst. The noble metal catalyst, model XT-CAT-01G, was purchased from Hunan Xintan New Materials Co., Ltd.; the rest is the same as in Example 1.

[0062] Comparative Example 2

[0063] A method for removing carbon monoxide from hydrogen-rich gas differs from Example 1 in that: a Hogarat catalyst of equal volume is used instead of the Fe-NC / ZrO2 catalyst, and the Hogarat catalyst was purchased from Hunan Xintan New Materials Co., Ltd.; the rest is the same as in Example 1.

[0064] Example 2

[0065] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the space velocity is 1000 h⁻¹. -1 The rest is the same as in Example 1.

[0066] Example 3

[0067] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the space velocity is 10000 h⁻¹. -1 The rest is the same as in Example 1.

[0068] Example 4

[0069] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the space velocity is 800 h⁻¹. -1 The rest is the same as in Example 1.

[0070] Example 5

[0071] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the space velocity is 13000 h⁻¹. -1 The rest is the same as in Example 1.

[0072] Example 6

[0073] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the volume fraction of carbon monoxide is 0.1 vol%; the rest is the same as in Example 1.

[0074] Example 7

[0075] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the volume fraction of carbon monoxide is 10 vol%; the rest is the same as in Example 1.

[0076] Example 8

[0077] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the volume fraction of carbon monoxide is 0.05 vol%; the rest is the same as in Example 1.

[0078] Example 9

[0079] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the volume fraction of carbon monoxide is 12 vol%; the rest is the same as in Example 1.

[0080] Example 10

[0081] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 2; the rest is the same as in Example 1.

[0082] Example 11

[0083] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 3; the rest is the same as in Example 1.

[0084] Example 12

[0085] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 4; the rest is the same as in Example 1.

[0086] Example 13

[0087] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 5; the rest is the same as in Example 1.

[0088] Example 14

[0089] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 6; the rest is the same as in Example 1.

[0090] Example 15

[0091] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 7; the rest is the same as in Example 1.

[0092] Example 16

[0093] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 8; the rest is the same as in Example 1.

[0094] Example 17

[0095] A method for removing carbon monoxide from hydrogen-rich gas, which differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 9; the rest is the same as in Example 1.

[0096] Example 18

[0097] A method for removing carbon monoxide from hydrogen-rich gas differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 10, and the reaction is carried out at a pressure of 1 MPa and a temperature of 50 °C; the rest of the process is the same as in Example 1.

[0098] Example 19

[0099] A method for removing carbon monoxide from hydrogen-rich gas differs from Example 1 in that the Fe-NC / ZrO2 catalyst is derived from Preparation Example 11, and the reaction is carried out at a pressure of 5 MPa and a temperature of 300 °C; the rest of the method is the same as in Example 1.

[0100] The concentrations of carbon monoxide and hydrogen were measured in the gaseous products after the reactions of Examples 1-19 and Comparative Examples 1-2. The hydrogen conversion rate was calculated as (moles of H2 entering the reactor - moles of H2 leaving the reactor) / moles of H2 entering the reactor. The results are shown in Table 1.

[0101] Table 1 Test results of Examples 1-19 and Comparative Examples 1-2

[0102]

[0103] Based on Table 1, the test results are analyzed as follows:

[0104] Compared with Comparative Examples 1 and 1-2, the carbon monoxide concentration of the reaction product in Example 1 is lower than that in Comparative Examples 1-2, and the hydrogen conversion rate in Example 1 is lower than that in Comparative Examples 1-2. The difference between Example 1 and Comparative Example 1 is that the catalyst used in Example 1 is a Fe-NC / ZrO2 catalyst; the mesoporous ZrO2 support of the Fe-NC / ZrO2 catalyst has a high specific surface area three-dimensional network structure, providing anchoring sites to promote rapid diffusion of reactants / products, and the active center is Fe-N. X The site exhibits weak hydrogen adsorption, is not prone to side reactions, and possesses high thermal stability and chemical inertness; therefore, it is evident that a Fe-NC / ZrO2 catalyst is necessary.

[0105] Comparing Examples 1 and 2-5, the carbon monoxide concentration of the reaction products in Examples 1 and 2-3 is lower than that in Examples 4-5, and the hydrogen conversion rate in Examples 1 and 2-3 is lower than that in Examples 4-5. The difference between Examples 1, 2-3, and 4-5 lies in the following: In Examples 1 and 2-3, the feed gas space velocity is 1000-10000 h⁻¹. Maintaining the space velocity within this range ensures a reasonable residence time on the catalyst, which helps reduce problems such as short contact time and decreased conversion rate due to excessively high space velocities, and localized overheating, catalyst failure, or exacerbated side reactions due to excessively low space velocities. Therefore, a feed gas space velocity of 1000-10000 h⁻¹ is optimal.

[0106] Comparing Examples 1 and 10, the carbon monoxide concentration of the reaction product in Example 1 is lower than that in Example 10, and the hydrogen conversion rate in Example 1 is lower than that in Example 10. The difference between Examples 1 and 10 is that the template agent used in Example 1 for the Fe-NC / ZrO2 catalyst preparation is P123. P123 is a triblock copolymer with hydrophilic-hydrophobic blocks capable of self-assembling micelles, guiding the hydrolysis and condensation of the ZrO2 precursor, and forming an ordered mesoporous structure after calcination. This results in better pore connectivity and pore size distribution, thus improving the catalyst's effectiveness. Therefore, using P123 as the template agent in the preparation of the Fe-NC / ZrO2 catalyst is superior.

[0107] Comparing Example 1 and Example 11, the carbon monoxide concentration of the reaction product in Example 1 is lower than that in Example 11, and the hydrogen conversion rate in Example 1 is lower than that in Example 11. The difference between Example 1 and Example 11 is that Y(NO3)3·6H2O was added during the preparation of the Fe-NC / ZrO2 catalyst used in Example 1; the introduction of Y(NO3)3·6H2O can yttrium doping of ZrO2, and Y³⁺ reacts with Zr... 4 ⁺ With similar ionic radii, they can enter the crystal lattice to introduce oxygen vacancies, enhance oxygen storage capacity and surface oxygen mobility, suppress phase transition, and improve thermal stability and catalytic effect; it can be seen that adding Y(NO3)3·6H2O during the preparation of the Fe-NC / ZrO2 catalyst is superior.

[0108] Comparing Examples 1 and 12-15, the carbon monoxide concentration of the reaction products in Examples 1 and 12-13 is lower than that in Examples 14-15, and the hydrogen conversion rate in Examples 1 and 12-13 is lower than that in Examples 14-15. The difference between Examples 1, 12-13, and 14-15 lies in the following: In Examples 1 and 12-13, the molar ratio of Y to Zr in the Fe-NC / ZrO2 catalyst is 1:(5-20). This is beneficial for generating sufficient oxygen vacancies while maintaining the integrity of the ZrO2 main structure, the openness of the mesoporous structure, and the high specific surface area, thus improving the final catalyst effect. Therefore, a molar ratio of Y to Zr of 1:(5-20) in the Fe-NC / ZrO2 catalyst is considered superior.

[0109] Comparing Examples 1 and 16, the carbon monoxide concentration in the reaction product of Example 1 is lower than that of Example 16, and the hydrogen conversion rate of Example 1 is lower than that of Example 16. The difference between Examples 1 and 16 is that cerium ammonium nitrate was added during the preparation of the Fe-NC / ZrO2 catalyst used in Example 1; the introduction of cerium ammonium nitrate allows cerium to be highly dispersed in the ZrO2 support in oxide form, utilizing the Ce³⁺ / Ce 4 The redox pair acts as an oxygen buffer, promotes continuous and efficient reaction, inhibits agglomeration and loss, and enhances catalytic effect; it can be seen that adding cerium ammonium nitrate during the preparation of the Fe-NC / ZrO2 catalyst is superior.

[0110] Comparing Examples 1 and 17, the carbon monoxide concentration of the reaction product in Example 1 is lower than that in Example 17, and the hydrogen conversion rate in Example 1 is lower than that in Example 17. The difference between Examples 1 and 17 lies in the pH adjustment agent used in the preparation of the Fe-NC / ZrO2 catalyst in Example 1: Tetramethylammonium hydroxide aqueous solution was used as the pH adjuster. Tetramethylammonium hydroxide rapidly and uniformly raises the pH through a high concentration of OH⁻, promoting uniform precipitation of zirconium ions. Quaternary ammonium cations adsorb onto the surface, inhibiting particle growth and aggregation, optimizing the mesoporous ZrO2 pore structure, exposing more active sites, and improving catalyst performance. Therefore, using tetramethylammonium hydroxide aqueous solution as the pH adjuster during the preparation of the Fe-NC / ZrO2 catalyst is superior.

[0111] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of protection claimed in this application.

Claims

1. A method for removing carbon monoxide from hydrogen-rich gas, characterized in that, The method includes the following steps: feeding a raw material gas into a reactor to contact it with a catalyst, and reacting at a reaction temperature of 50-300℃ and a pressure of 1-5MPa. The catalyst is an Fe-NC / ZrO2 catalyst, and its preparation method includes the following steps: S1: Dissolve ZrOCl2·8H2O, Y(NO3)3·6H2O and cerium ammonium nitrate in an ethanol / water mixed solvent, add a pH adjuster to adjust the pH to 9-10 to form a sol, add a template agent to obtain a mesoporous ZrO2 support, wherein the amount of cerium ammonium nitrate added is 0.5-1% of the mass of ZrOCl2·8H2O; S2: Disperse the mesoporous ZrO2 support in a polyaniline solution, add FeCl3, stir, filter, and dry the filter cake to obtain the precursor powder; S3: The precursor powder is placed in a reactor and carbonized at 700-900℃ for 1-3 hours under an inert gas to obtain the Fe-NC / ZrO2 catalyst.

2. The method for removing carbon monoxide from hydrogen-rich gas according to claim 1, characterized in that, The gas space velocity of the raw material is 1000-10000 h⁻¹.

3. The method for removing carbon monoxide from hydrogen-rich gas according to claim 1, characterized in that, The volume fraction of carbon monoxide in the feed gas is 0.1-10 vol.

4. The method for removing carbon monoxide from hydrogen-rich gas according to claim 1, characterized in that, The template agent in step S1 is P123 template agent.

5. The method for removing carbon monoxide from hydrogen-rich gas according to claim 1, characterized in that, The molar ratio of Y to Zr is 1:(5-20).

6. The method for removing carbon monoxide from hydrogen-rich gas according to claim 1, characterized in that, In step S1, the pH adjuster is an aqueous solution of tetramethylammonium hydroxide.

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