Double-interface functional site high-sulfur-resistant moisture-resistant CO oxidation catalyst as well as macro-quantity preparation method and application of double-interface functional site high-sulfur-resistant moisture-resistant CO oxidation catalyst

Abstract

The invention provides a CO oxidation catalyst with high sulfur resistance and water vapor resistance as well as a preparation method and application of the CO oxidation catalyst. According to the industrial CO oxidation catalyst which is high in CO catalytic activity, high in sulfur resistance and water vapor resistance, long in service life and low in cost, the inner layer is a non-noble metal active component, the outer layer is a noble metal auxiliary active component to construct a double-interface functional site, after CO completes an adsorption process on the surface, lattice oxygen in the active component of the inner layer is utilized to complete a CO oxidation process, and therefore the CO oxidation process is completed. Under the synergistic effect, the catalyst has efficient and stable CO oxidation capacity. The CO conversion rate is higher than 95% under the severe flue gas condition that 100 ppm of SO2 and 20% of H2O are introduced, and stable operation lasts for more than 1000 hours. The double-interface functional sites have stronger affinity, can enhance the adsorption of CO on the surface of the catalyst and inhibit the adsorption of SO2, have excellent sulfur and water vapor poisoning resistance, and are suitable for CO oxidation removal of sintering flue gas and boiler flue gas under high-sulfur and water vapor-containing conditions in the iron and steel industry.

Description

Technical Field

[0001] The present invention belongs to the technical field of CO oxidation catalysts, and relates to a CO oxidation catalyst, a preparation method and an application thereof, and particularly relates to a CO oxidation catalyst with dual-interface functional sites, high sulfur resistance and high water vapor resistance, a macroscale preparation method and an application thereof. Background Art

[0002] Carbon monoxide (CO) is the most abundant pollutant in the urban air environment (accounting for about 1 / 3 of the total atmospheric pollutants), mainly derived from the incomplete combustion of carbon-containing substances, such as industrial production, heating, and waste incineration. Taking the steel industry as an example, the total amount of CO emitted from the incomplete combustion of fossil fuels in the steel production process reaches 50 million to 60 million tons per year, seriously threatening human health and the ecological system. The "Notice on the Implementation of Emission Limits for Carbon Monoxide at the Head of Sintering Machines of Iron and Steel Enterprises" issued by Tangshan in 2018 requires that the carbon monoxide emission concentration at the head of sintering machines of all iron and steel enterprises in the city does not exceed 6000 mg / m 3 3. The national standard of the People's Republic of China - Municipal Solid Waste Incineration Pollution Control Standard GB18485-2014 issued by the Ministry of Ecology and Environment in 2014 stipulates that the limit value of the carbon monoxide concentration in the flue gas discharged from newly built municipal solid waste incinerators is 100 mg / m for a 1-hour average value 3 3. Therefore, the ultra-low emission of CO has become the top priority in the treatment of atmospheric pollutants.

[0003] Currently, among many CO emission reduction technologies, the catalytic oxidation method has the advantages of low investment, low operating energy consumption, no secondary pollution, and high CO emission reduction efficiency, and has become the most important method in CO emission reduction technologies. The catalyst is the core of the catalytic oxidation method technology, mainly composed of a carrier and an active component. Considering the complex flue gas conditions, the catalyst should have excellent CO performance and excellent sulfur and water vapor poisoning resistance. China's emission standard for SO2 in flue gas is 100 mg / Nm 3 3. Therefore, even after desulfurization and dust removal operations, there will still be SO2 and H2O in the flue gas, which are likely to compete with CO for adsorption, resulting in a decrease in the CO oxidation activity, and are likely to sulfonate the active component under their combined action, causing the catalyst to be poisoned and deactivated.

[0004] The active components of CO oxidation catalysts are mainly divided into two categories: non-noble metals and noble metals. Non-noble metals such as Cu, Mn, and Co have good catalytic oxidation performance for CO. For example, the Hopcalite catalyst developed in the United States is mainly made of manganese dioxide and copper oxide in a certain proportion, showing good CO oxidation performance. It is a commercially available catalyst widely used under clean flue gas conditions at present. However, the high sensitivity of Mn and Cu to SO2 makes its stability poor under conditions containing sulfur and water vapor, and it is easy to be poisoned and inactivated. Currently, in order to improve the sulfur and water vapor poisoning resistance performance of the catalyst, noble metals are mostly used as the main active components, mainly including noble metals such as Pt, Pd, Au, and Ag. For example, Pt-loaded ZSM-5 molecular sieve catalyst is often used in the CO emission reduction of automobile exhaust. However, the noble metal loading of this type of catalyst in the current market often reaches 1 wt% and above. The high cost of noble metals and the non-renewability of resources limit its large-scale promotion to a certain extent.

[0005] Therefore, how to design a more suitable CO oxidation catalyst to solve the above problems existing in the existing CO oxidation catalysts has become one of the focuses widely concerned by many front-line researchers in the industry. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a CO oxidation catalyst and its preparation method and application, especially a CO oxidation catalyst with dual interface functional sites and high sulfur and water vapor resistance and its large-scale preparation method. The CO oxidation catalyst provided by the present invention has the characteristics of high CO catalytic activity, high sulfur and water vapor resistance performance, long service life and low cost. Moreover, the preparation method is simple, the conditions are mild, the controllability is good, the stability is strong, and it is more suitable for the promotion and application of industrial production.

[0007] The present invention provides a CO oxidation catalyst, comprising: a carrier and an active component and a promoter component compounded on the carrier;

[0008] The carrier is a cordierite carrier;

[0009] The active component is two or more of CuO, MnO2, Co3O4, CeO2, and La2O3;

[0010] The promoter component is one or more of Pd, Au, Pt, and Ru.

[0011] Preferably, the CO oxidation catalyst is specifically a CO oxidation catalyst with dual interface functional sites;

[0012] The active component accounts for 5% - 25% of the total mass of the catalyst;

[0013] The promoter component accounts for 0.01% - 0.1% of the total mass of the catalyst;

[0014] The CO oxidation catalyst includes a highly sulfur- and water-vapor-resistant CO oxidation catalyst.

[0015] Preferably, the carrier accounts for 74.9% to 94.99% of the total mass of the catalyst;

[0016] The carrier has a structure combining a non-noble metal active component layer and a noble metal co-active component layer;

[0017] The non-noble metal active component layer is the inner layer of the catalyst and the outer layer of the noble metal co-active component compounded on the inner layer of the catalyst.

[0018] The present invention also provides a preparation method of a CO oxidation catalyst as described in any one of the above technical solutions, including the following steps:

[0019] 1) After treating cordierite with acid and the first calcination, pretreated cordierite is obtained;

[0020] The active component precursor is calcined for the second time to obtain an active component powder;

[0021] 2) The pretreated cordierite obtained in the above step is placed in a mixed solution of an active component powder, a binder, a dispersant, and water for the first impregnation, and then after the third calcination, cordierite loaded with the active component is obtained;

[0022] 3) After adjusting the pH value of the co-active component precursor solution, the cordierite loaded with the active component obtained in the above step is placed therein for the second impregnation, and then after the fourth calcination, a CO oxidation catalyst is obtained.

[0023] Preferably, the acid treatment is specifically carried out by immersing in an acid solution;

[0024] The acid solution includes hydrochloric acid and / or oxalic acid solution;

[0025] The mass concentration of the acid solution is 10% to 30%;

[0026] The temperature of the acid treatment is 60 to 100 °C;

[0027] The time of the acid treatment is 1 to 4 h.

[0028] Preferably, the temperatures of the first calcination, the second calcination, the third calcination, and the fourth calcination are each independently selected from 300 to 600 °C;

[0029] The times of the first calcination, the second calcination, the third calcination, and the fourth calcination are each independently selected from 4 to 8 h;

[0030] The active component precursor includes one or more of acetates, nitrates, sulfates, carbonates, chlorides, and oxides of the active component.

[0031] Preferably, the binder includes an acidic silica sol solution;

[0032] The dispersant includes polyethylene glycol;

[0033] The mass ratio of the active component powder to SiO2 in the acidic silica sol solution is (1-2.5):(0.3-1.2);

[0034] The mass ratio of the active component powder to the dispersant is (1-2.5):(0.5-1).

[0035] Preferably, the temperatures of the first impregnation and the second impregnation are each independently selected from 20-60°C;

[0036] The times of the first impregnation and the second impregnation are each independently selected from 0.1-2 h;

[0037] The promoter active component precursor includes one or more of palladium chloride, palladium nitrate, sodium chloroaurate, platinum nitrate, chloroplatinic acid, and ruthenium chloride;

[0038] The pH value is adjusted to 8-10.

[0039] Preferably, when there are multiple promoter active components, step 3) is specifically the following steps:

[0040] After adjusting the pH value of the first promoter active component precursor solution, place the cordierite loaded with the active component therein for the second impregnation and then dry it, and then place it in the second promoter active component precursor solution for the third impregnation and then dry it, and so on. Finally, after the fourth calcination, a CO oxidation catalyst is obtained;

[0041] The drying temperature is 60-120°C;

[0042] The drying time is 2-6 h.

[0043] The present invention provides the application of the CO oxidation catalyst described in any one of the above technical solutions or the CO oxidation catalyst prepared by the preparation method described in any one of the above technical solutions in treating sulfur-containing, water-vapor-containing, and carbon-containing waste gas.

[0044] The present invention provides a CO oxidation catalyst, comprising: a support and active components and promoter active components supported on the support; the support is a cordierite support; the active components are two or more of CuO, MnO2, Co3O4, CeO2 and La2O3; the promoter active components are one or more of Pd, Au, Pt and Ru. Compared with the prior art, the present invention creatively designs a CO oxidation catalyst with a specific composition and structure, which is an industrial CO oxidation catalyst with high CO catalytic activity, high sulfur and water vapor resistance, long service life and low cost.

[0045] For the CO oxidation catalyst provided by the present invention, the inner layer of the catalyst is a non-noble metal active component, and the outer layer is a noble metal promoter active component to form a double-interface functional site. After CO completes the adsorption process on the catalyst surface, the lattice oxygen in the inner layer active component is used to complete the CO oxidation process. Under this synergistic effect, it has high-efficiency and stable CO oxidation ability. Under the harsh flue gas conditions of 225 °C, 100 ppm SO2 and 20 (vol)% H2O introduced in the present invention, the CO conversion rate is not less than 95%, and it can operate stably for more than 1000 hours. The double-interface functional site has a stronger affinity for CO, can enhance the adsorption of CO on the catalyst surface, and inhibit the adsorption process of SO2, and has excellent sulfur and water vapor poisoning resistance performance, and is particularly suitable for CO oxidation removal under high-sulfur and water-vapor conditions in sintering flue gas and boiler flue gas in the steel industry.

[0046] The present invention also provides a corresponding large-scale preparation method, which uses a solution super-dispersion impregnation process to load hierarchical noble metals, and the overall noble metal content is ≤ 0.1 wt%, which greatly reduces the catalyst preparation cost and has good technical economy. The catalyst provided by the present invention is a supported monolithic self-supporting catalyst, which has strong chemical stability and mechanical stability, and is prepared by a simple solution super-dispersion impregnation process, which greatly simplifies the preparation process of the monolithic catalyst, is simple and easy to operate, and can be applied to the emission control of CO gas in large-scale industrial flue gas.

[0047] Experimental results show that the catalyst prepared by the present invention has a CO conversion rate of not less than 95% under the flue gas conditions of 4000 ppm CO, 10 (vol)% O2, 100 ppm SO2 and 20 (vol)% H2O at a test temperature of 225 °C and a volumetric space velocity (GHSV) of 7500 h -1 and can operate stably for more than 1000 hours, with a long service life; even at a test temperature of 250 °C and a volumetric space velocity (GHSV) of 7500 h -1, when introducing 4000 ppm CO, 10 (vol)% O2, 4500 ppm SO2, and 5 (vol)% H2O, the CO conversion rate under the high-sulfur and severe flue gas conditions is still above 95%, and the deactivation rate during 48-hour operation is ≤ 5%. The activity and anti-poisoning stability are leading in the current domestic and foreign reports. Description of the Drawings

[0048] Figure 1 It is the activity curve of the stability test of the catalyst prepared by the present invention under low-sulfur and high-water-vapor conditions;

[0049] Figure 2 It is the activity curve of the stability test of the catalyst prepared by the present invention under high-sulfur and low-water-vapor conditions. Detailed Embodiments

[0050] To further understand the present invention, the preferred implementation modes of the present invention will be described below in conjunction with the embodiments. However, it should be understood that these descriptions are only for further explaining the features and advantages of the present invention rather than limiting the claims of the present invention.

[0051] For all raw materials of the present invention, there is no particular limitation on their sources, and they can be purchased on the market or prepared according to the conventional methods well-known to those skilled in the art.

[0052] For the raw materials used in the present invention, there is no particular limitation on their purity, and analytical purity or the purity requirements for preparing CO oxidation catalysts well-known to those skilled in the art can be adopted.

[0053] The present invention provides a CO oxidation catalyst, including: a carrier and an active component and a promoter component compounded on the carrier;

[0054] The carrier is a cordierite carrier;

[0055] The active component is two or more of CuO, MnO2, Co3O4, CeO2, and La2O3;

[0056] The promoter component is one or more of Pd, Au, Pt, and Ru.

[0057] In the present invention, the active component is one or more of Pd, Au, Pt, and Ru, and can be Pd, Au, Pt, or Ru.

[0058] In the present invention, the CO oxidation catalyst is preferably specifically a CO oxidation catalyst with dual interface functional sites.

[0059] In the present invention, the active component preferably accounts for 5% - 25% of the total mass of the catalyst, more preferably 7% - 23%, more preferably 10% - 20%, and more preferably 13% - 17%.

[0060] In the present invention, the promoter component preferably accounts for 0.01% to 0.1% of the total mass of the catalyst, more preferably 0.03% to 0.08%, and even more preferably 0.05% to 0.06%.

[0061] In the present invention, the CO oxidation catalyst preferably includes a high sulfur and water vapor resistant CO oxidation catalyst.

[0062] In the present invention, the mass of the carrier preferably accounts for 74.9% to 94.99% of the total mass of the catalyst, more preferably 80% to 90%, and even more preferably 84% to 85%.

[0063] In the present invention, the carrier preferably has a structure in which a non-noble metal active component layer and a noble metal promoter component layer are combined.

[0064] In the present invention, the non-noble metal active component layer is preferably the inner layer of the catalyst and the outer layer of the noble metal promoter component composite on the inner layer of the catalyst.

[0065] In the present invention, the active component in the inner layer of the catalyst preferably contains lattice oxygen.

[0066] The present invention provides a method for preparing a CO oxidation catalyst according to any one of the above technical solutions, comprising the following steps:

[0067] 1) After acid treatment and first calcination of cordierite, pretreated cordierite is obtained;

[0068] After second calcination of the active component precursor, an active component powder is obtained;

[0069] 2) The pretreated cordierite obtained in the above step is placed in a mixed solution of an active component powder, a binder, a dispersant and water for first impregnation, and then after third calcination, cordierite loaded with the active component is obtained;

[0070] 3) After adjusting the pH value of the promoter component precursor solution, the cordierite loaded with the active component obtained in the above step is placed therein for second impregnation, and then after fourth calcination, a CO oxidation catalyst is obtained.

[0071] In the present invention, first, cordierite is subjected to acid treatment and first calcination to obtain pretreated cordierite;

[0072] After second calcination of the active component precursor, an active component powder is obtained.

[0073] In the present invention, the acid treatment is specifically preferably carried out by immersing in an acid solution.

[0074] In the present invention, the acid solution preferably comprises hydrochloric acid and / or oxalic acid solution, more preferably hydrochloric acid or oxalic acid solution.

[0075] In the present invention, the mass concentration of the acid solution is preferably 10% to 30%, more preferably 14% to 26%, and even more preferably 18% to 22%.

[0076] In the present invention, the temperature of the acid treatment is preferably 60 to 100 °C, more preferably 65 to 95 °C, even more preferably 70 to 90 °C, and even more preferably 75 to 85 °C.

[0077] In the present invention, the time of the acid treatment is preferably 1 to 4 h, more preferably 1.5 to 3.5 h, and even more preferably 2 to 3 h.

[0078] In the present invention, the temperatures of the first calcination, the second calcination, the third calcination, and the fourth calcination are each independently preferably selected from 300 to 600 °C, more preferably 350 to 550 °C, and even more preferably 400 to 500 °C.

[0079] In the present invention, the times of the first calcination, the second calcination, the third calcination, and the fourth calcination are each independently preferably selected from 4 to 8 h, more preferably 4.5 to 7.5 h, even more preferably 5 to 7 h, and even more preferably 5.5 to 6.5 h.

[0080] In the present invention, the active component precursor preferably comprises one or more of acetates, nitrates, sulfates, carbonates, chlorides, and oxides of the active component, more preferably acetates, nitrates, sulfates, carbonates, chlorides, or oxides of the active component.

[0081] In the present invention, the pretreated cordierite obtained in the above steps is placed in a mixed solution of the active component powder, the binder, the dispersant, and water for the first impregnation, and then after the third calcination, cordierite loaded with the active component is obtained.

[0082] In the present invention, the binder preferably comprises an acidic silica sol solution.

[0083] In the present invention, the dispersant comprises polyethylene glycol;

[0084] In the present invention, the mass ratio of the active component powder to SiO2 in the acidic silica sol solution is preferably (1 to 2.5):(0.3 to 1.2), more preferably (1.3 to 2.2):(0.5 to 1.0), and even more preferably (1.5 to 2.0):(0.7 to 0.9).

[0085] In the present invention, the mass ratio of the active component powder to the dispersant is preferably (1 - 2.5):(0.3 - 1.2), more preferably (1.3 - 2.2):(0.5 - 1.0), and even more preferably (1.5 - 2.0):(0.7 - 0.9).

[0086] In the present invention, the temperatures of the first impregnation and the second impregnation are each independently preferably selected from 20 - 60 °C, more preferably 25 - 55 °C, even more preferably 30 - 50 °C, and even more preferably 35 - 45 °C.

[0087] In the present invention, the times of the first impregnation and the second impregnation are each independently preferably selected from 0.1 - 2 h, more preferably 0.5 - 1.6 h, and even more preferably 0.9 - 1.2 h.

[0088] Finally, after adjusting the pH value of the promoter active component precursor solution in the present invention, the cordierite loaded with the active component obtained in the above steps is placed therein for the second impregnation, and then after the fourth calcination, a CO oxidation catalyst is obtained.

[0089] In the present invention, the promoter active component precursor preferably includes one or more of palladium chloride, palladium nitrate, sodium chloroaurate, platinum nitrate, chloroplatinic acid, and ruthenium chloride, and more preferably palladium chloride, palladium nitrate, sodium chloroaurate, platinum nitrate, chloroplatinic acid, or ruthenium chloride.

[0090] In the present invention, the pH value adjustment is preferably 8 - 10, more preferably 8.4 - 9.6, and even more preferably 8.8 - 9.2.

[0091] In the present invention, when there are multiple promoter active components, step 3) is specifically preferably the following steps:

[0092] Adjust the pH value of the first promoter active component precursor solution, then place the cordierite loaded with the active component therein for the second impregnation and then dry, then place it in the second promoter active component precursor solution for the third impregnation and then dry, and so on. Finally, after the fourth calcination, a CO oxidation catalyst is obtained;

[0093] In the present invention, the drying temperature is preferably 60 - 120 °C, more preferably 70 - 110 °C, and even more preferably 80 - 100 °C.

[0094] In the present invention, the drying time is preferably 2 - 6 h, more preferably 2.5 - 5.5 h, even more preferably 3 - 5 h, and even more preferably 3.5 - 4.5 h.

[0095] The present invention provides the application of the CO oxidation catalyst according to any one of the above technical solutions or the CO oxidation catalyst prepared by the preparation method according to any one of the above technical solutions in treating sulfur-containing, water-vapor-containing, and carbon-containing waste gases.

[0096] In the present invention, the carbon-containing waste gas is preferably a carbon-containing waste gas including CO, and more preferably a carbon-containing waste gas containing sulfur, water and CO.

[0097] The present invention belongs to the technical field of preparation of highly efficient anti-poisoning catalysts, and provides a method for macroscopically preparing a highly anti-sulfur and anti-water-vapor CO oxidation catalyst with dual-interface functional sites and its application. In this catalyst preparation method, cordierite is used as the carrier, and two or several of CuO, MnO2, Co3O4, CeO2, and La2O3 are used as active components, and one or several of Pd, Au, Pt, and Ru are used as co-active components. Without a complicated hydrothermal and reduction activation process, a monolithic CO oxidation catalyst with dual-interface functional sites is prepared by a solution super-dispersion impregnation process. The catalyst preparation method provided by the present invention is simple, easy to realize the macroscopic preparation of the monolithic catalyst, and adopts a combination of a non-noble metal-based + noble metal-based layer, effectively reducing the content of noble metals. The overall noble metal content is ≤0.1 wt%, greatly reducing the production cost. Under the synergistic effect of the non-noble metal-based + noble metal-based components, the dual-interface functional sites have a stronger affinity for CO, can enhance the adsorption of CO on the catalyst surface, and inhibit the adsorption process of SO2, and have excellent anti-sulfur and anti-water-vapor poisoning performance, and are particularly suitable for the CO oxidation and removal under the conditions of high sulfur and water vapor in sintering flue gas and boiler flue gas in the steel industry. The catalyst provided by the present invention has the advantages of high anti-sulfur and anti-water-vapor poisoning performance and low cost.

[0098] The catalyst prepared by the present invention, when introducing 4000 ppm CO, 10% O2, GHSV = 7500 h -1 , within the wide temperature range of 150 - 300 °C: the CO conversion rate is not less than 97%; at the same time, it has excellent anti-sulfur and anti-water-vapor poisoning stability performance. When introducing 100 ppm SO2, 20% vol H2O, GHSV = 7500 h -1 , and at 225 °C, the CO conversion rate is always maintained above 95%, and it can stably operate for more than 1000 h; even at the test temperature of 250 °C, the volumetric space velocity (GHSV) is 7500 h -1 , when introducing 4000 ppm CO, 10 (vol)% O2, 4500 ppm SO2, 5 (vol)% H2O under the condition of high-sulfur and severe flue gas, the CO conversion rate is still above 95%, and the inactivation rate during 48 h of operation is ≤5%. The activity and anti-poisoning stability are leading in the current domestic and foreign reports.

[0099] The present invention is to complete and refine the overall technical solution, better ensure the composition and structure of the CO oxidation catalyst, further improve the catalytic activity, sulfur and water vapor resistance performance and service life of the CO oxidation catalyst, and reduce the cost. The above-mentioned dual-interface functional site highly sulfur and water vapor resistant CO oxidation catalyst, its mass preparation method and application can specifically include the following contents:

[0100] A mass preparation method and application of a dual-interface functional site highly sulfur and water vapor resistant CO oxidation catalyst, including a carrier, an active component and a promoter component;

[0101] The carrier is a cordierite carrier;

[0102] The active component is two or more of CuO, MnO2, Co3O4, CeO2, La2O3;

[0103] The promoter component is one or more of noble metals Pd, Au, Pt, Ru;

[0104] Specifically, the active component accounts for 5-25% of the total mass of the catalyst.

[0105] Specifically, the promoter component accounts for 0.01-0.1% of the total mass of the catalyst.

[0106] Specifically, the carrier accounts for 74.9-94.99% of the total mass of the catalyst.

[0107] The present invention provides a preparation method of the dual-interface functional site highly sulfur and water vapor resistant CO oxidation catalyst according to any one of the above technical solutions, including the following steps:

[0108] (1) Immerse the cordierite in an acid solution with a certain mass concentration and pretreat it at a certain temperature for a period of time;

[0109] (2) Wash the cordierite clean, then perform the first drying and the first calcination to obtain the acid-pretreated cordierite;

[0110] (3) Mechanically mix and grind two or more of the active component precursors such as copper salts, manganese salts, cobalt salts, cerium salts, and lanthanum salts, and obtain an active component powder after the second calcination, denoted as (Cu / Mn / Co / Ce / La)Ox;

[0111] (4) According to the quantitative ratio relationship, fully mix the active component powder with a binder, a dispersant and water to form an ultra-dispersed solution, then perform the first impregnation coating on the cordierite, maintain it at a certain temperature for a period of time, and then obtain cordierite-(Cu / Mn / Co / Ce / La)Ox after the second drying and the third calcination;

[0112] (5) Select one or more of Pd, Au, Pt, and Ru sources as the precursor solution of the promoter active component, adjust the pH of the precursor solution to 8-10 using ammonia water, and then perform the second impregnation coating on the surface of cordierite-(Cu / Mn / Co / Ce / La)Ox; perform the third drying to obtain cordierite-(Cu / Mn / Co / Ce / La)Ox-Pd / Au / Pt / Ru;

[0113] (6) Select one or more precursor solutions of Pd, Au, Pt, and Ru, and then perform the third impregnation coating on cordierite-(Cu / Mn / Co / Ce / La)Ox-Pd / Au / Pt / Ru, followed by the fourth drying and the fourth calcination to obtain the dual-interface functional site high anti-sulfur and anti-water-vapor CO oxidation catalyst cordierite-(Cu / Mn / Co / Ce / La)Ox-(Pd / Au / Pt / Ru)Ox.

[0114] Specifically, in step (1), the acid pretreatment temperature is 60-100 °C, and the pretreatment time is 1-4 h.

[0115] Specifically, the temperatures of the first impregnation coating and the second impregnation coating are independently 20-60 °C, and the impregnation coating times are independently 0.1-2 h.

[0116] Specifically, the temperatures of the first drying, the second drying, the third drying, and the fourth drying are independently 60-120 °C, and the drying times are independently 2-6 h.

[0117] Specifically, the temperatures of the first calcination, the second calcination, the third calcination, and the fourth calcination are independently 300-600 °C, and the calcination times are independently 4-8 h.

[0118] Specifically, the acid solution in step (1) is hydrochloric acid or oxalic acid solution.

[0119] Specifically, in step (3), the copper salt in the active component precursor comes from one or more of copper acetate, copper nitrate, copper sulfate, and copper chloride, the manganese salt comes from one or more of manganese nitrate, manganese chloride, manganese acetate, and manganese dioxide, the cobalt salt comes from one or more of cobalt acetate, cobalt chloride, cobalt sulfate, and cobalt nitrate, the cerium salt comes from one or more of cerium nitrate, cerium sulfate, cerium acetate, and lanthanum cerium carbonate, and the lanthanum salt comes from one or more of lanthanum nitrate, lanthanum chloride, and lanthanum acetate.

[0120] Specifically, the binder in step (4) is acidic silica sol.

[0121] Specifically, the dispersant in step (4) is polyethylene glycol.

[0122] Specifically, the Pd source of the promoter precursor solution described in steps (5) and (6) is selected from one of palladium chloride solution and palladium nitrate solution, the Au source is sodium chloroaurate solution, the Pt source is selected from one of platinum nitrate solution and chloroplatinic acid solution, and the Ru source is ruthenium chloride solution.

[0123] Specifically, the mass fraction of the acid solution described in step (1) is 10% - 30%.

[0124] Specifically, the mass ratio of the active component powder and SiO2 in the acidic silica sol solution described in step (4) is 1 - 2.5:0.3 - 1.2.

[0125] Specifically, the mass ratio of the active component powder and polyethylene glycol described in step (4) is 1 - 2.5:0.5 - 1.

[0126] Specifically, the mass ratio of the active component powder and water described in step (4) is 0.4 - 1:1 - 3.

[0127] Specifically, the mass fraction concentration of ammonia water described in step (5) is 0.1% - 4%.

[0128] The present invention also provides the application of the dual - interface functional - site high - sulfur - resistant and water - vapor - resistant CO oxidation catalyst described in any one of the above technical solutions or the dual - interface functional - site high - sulfur - resistant and water - vapor - resistant CO oxidation catalyst obtained by the preparation method described in any one of the above technical solutions in treating carbon - containing waste gas under sulfur - containing and water - vapor - containing conditions.

[0129] The above content of the present invention provides a CO oxidation catalyst, its preparation method and application, especially relates to a dual - interface functional - site high - sulfur - resistant and water - vapor - resistant CO oxidation catalyst, its large - scale preparation method and application. The CO oxidation catalyst designed by the present invention with a specific composition and structure is an industrial CO oxidation catalyst with high CO catalytic activity, high sulfur - resistant and water - vapor - resistant performance, long service life and low cost. For the CO oxidation catalyst provided by the present invention, the inner layer of the catalyst is a non - noble - metal active component, and the outer layer is a noble - metal promoter component to form a dual - interface functional site. After CO completes the adsorption process on the catalyst surface, the lattice oxygen in the inner - layer active component is used to complete the CO oxidation process. Under this synergistic effect, it has an efficient and stable CO oxidation ability. Under the harsh flue - gas conditions of 225 °C, 100 ppm SO2 and 20 (vol)% H2O, the CO conversion rate of the present invention is not less than 95%, and it can operate stably for more than 1000 hours. The dual - interface functional site has a stronger affinity for CO, can enhance the adsorption of CO on the catalyst surface, and inhibit the adsorption process of SO2, and has excellent sulfur - resistant and water - vapor - resistant poisoning performance, and is especially suitable for the CO oxidation removal under high - sulfur and water - vapor - containing conditions of sintering flue gas and boiler flue gas in the steel industry.

[0130] The present invention also provides a corresponding macro - preparation method, which uses a solution hyper - dispersion impregnation process to load hierarchical noble metals. The overall noble metal content is ≤0.1 wt%, greatly reducing the catalyst preparation cost and having good technical economy. The catalyst provided by the present invention is a supported monolithic self - supporting catalyst, which has strong chemical stability and mechanical stability. It is prepared by a simple solution hyper - dispersion impregnation process, greatly simplifying the preparation process of the monolithic catalyst. The operation is simple and easy, and it can be applied to the emission control of CO gas in large - scale industrial flue gas.

[0131] The experimental results show that the catalyst prepared by the present invention has a CO conversion rate of not less than 95% under the flue gas conditions of a test temperature of 225°C, a space velocity (GHSV) of 7500 h -1 , a CO concentration of 4000 ppm, an O2 concentration of 10 (vol)%, an SO2 concentration of 100 ppm, and an H2O concentration of 20 (vol)%, and can stably operate for more than 1000 hours, with a long service life. See Figure 1 , Figure 1 which is the activity curve of the stability test of the catalyst prepared by the present invention under low - sulfur and high - water - vapor conditions.

[0132] Even under the harsh flue gas conditions of a test temperature of 250°C, a space velocity (GHSV) of 7500 h -1 , a CO concentration of 4000 ppm, an O2 concentration of 10 (vol)%, an SO2 concentration of 4500 ppm, and an H2O concentration of 5 (vol)%, the CO conversion rate of the catalyst prepared by the present invention is still above 95%, and the deactivation rate during 48 - hour operation is ≤5%. See Figure 2 , Figure 2 which is the activity curve of the stability test of the catalyst prepared by the present invention under high - sulfur and low - water - vapor conditions.

[0133] The activity and anti - poisoning stability of the catalyst prepared by the present invention are leading in current domestic and foreign reports.

[0134] To further illustrate the present invention, the following examples are used to describe in detail a CO oxidation catalyst provided by the present invention, its preparation method, and its application. However, it should be understood that these examples are implemented on the premise of the technical solution of the present invention, giving detailed implementation methods and specific operation processes, only to further illustrate the features and advantages of the present invention, rather than limiting the claims of the present invention. The protection scope of the present invention is not limited to the following examples.

[0135] Example 1

[0136] This example provides a preparation method and application of a dual - interface functional - site high - sulfur - resistant and high - water - vapor - resistant CO oxidation catalyst, including the following steps:

[0137] (1) Immerse 10 g of monolithic cordierite into a 10 wt% oxalic acid solution, perform constant-temperature treatment at 70 °C for 3 h, then take out the cordierite and rinse it with deionized water 3 - 4 times, then dry the cordierite at 120 °C for 6 h, and finally calcine the cordierite at 400 °C for 3 h to obtain a pretreated cordierite support;

[0138] (2) Take 6.92 g of manganese acetate, 16.87 g of cobalt sulfate hexahydrate, and 7.3 g of copper nitrate trihydrate in a mortar and mix them mechanically by grinding, then calcine at 450 °C for 4 h to obtain an active component powder, denoted as MnO₂-Co₃O₄-CuO;

[0139] (3) Take 4.25 g of the active component powder, 8.5 g of acidic silica sol, 3 g of polyethylene glycol, and 9.25 g of deionized water to prepare an ultra-dispersed solution. Immerse the pretreated cordierite support into the coating solution and maintain it at 30 °C for 0.5 h, then take it out, drain the excess coating solution in the pores, and dry it at 120 °C for 6 h, and finally calcine at 450 °C for 4 h to obtain cordierite-MnO₂-Co₃O₄-CuO;

[0140] (4) Take 0.4 ml of a palladium chloride solution with a mass concentration of 12 mg / ml in a beaker, then adjust the pH of the solution to 9 with 4 wt% ammonia water and coat it on the surface of cordierite-active component, and dry it at 120 °C for 5 h to obtain cordierite-MnO₂-Co₃O₄-CuO-Pd;

[0141] (5) Take 0.5 ml of a ruthenium chloride solution with a mass concentration of 10 mg / ml in a beaker, then coat it on the surface of cordierite-MnO₂-Co₃O₄-CuO-Pd, and dry it at 120 °C for 5 h, and finally calcine at 500 °C for 4 h to obtain the final finished catalyst cordierite-MnO₂-Co₃O₄-CuO-PdO-RuO₂.

[0142] Example 2

[0143] This example provides a preparation method and application of a dual-interface functional site highly sulfur- and water-vapor-resistant CO oxidation catalyst, including the following steps:

[0144] (1) Immerse 10 g of monolithic cordierite into a 10 wt% oxalic acid solution, perform constant-temperature treatment at 70 °C for 3 h, then take out the cordierite and rinse it with deionized water 3 - 4 times, then dry the cordierite at 120 °C for 6 h, and finally calcine the cordierite at 400 °C for 3 h to obtain a pretreated cordierite support;

[0145] (2) Take 7.3 g of copper nitrate trihydrate, 8.68 g of cerium nitrate hexahydrate, and 7.1 g of lanthanum chloride hexahydrate in a mortar and mix them mechanically by grinding, then calcine at 450 °C for 4 h to obtain an active component powder, denoted as CuO-CeO₂-La₂O₃;

[0146] (3) Weigh 4.25 g of the active component powder, 8.5 g of acidic silica sol, 3 g of polyethylene glycol, and 9.25 g of deionized water to prepare a hyper-dispersion solution. Immerse the pretreated cordierite support in the coating solution at 30 °C for 0.5 h, then take it out, drain the excess coating solution in the pores, and dry it at 120 °C for 6 h. Finally, calcine it at 450 °C for 4 h to obtain cordierite-CuO-CeO2-La2O3;

[0147] (4) Take 0.4 ml of palladium chloride solution with a mass concentration of 12 mg / ml in a beaker, then adjust the pH of the solution to 9 with 4 wt% ammonia water and coat it on the surface of cordierite-active component. Dry it at 120 °C for 5 h to obtain cordierite-CuO-CeO2-La2O3-Pd;

[0148] (5) Take 0.5 ml of ruthenium chloride solution with a mass concentration of 10 mg / ml in a beaker, then coat it on the surface of cordierite-MnO2-Co3O4-CeO2-Pd, and dry it at 120 °C for 5 h. Finally, calcine it at 500 °C for 4 h to obtain the final product catalyst cordierite-CuO-CeO2-La2O3-PdO-RuO2.

[0149] Example 3

[0150] This example provides a preparation method and application of a dual-interface functional site high anti-sulfur and anti-water-vapor CO oxidation catalyst, including the following steps:

[0151] (1) Immerse 10 g of monolithic cordierite in 10 wt% oxalic acid solution, treat it at a constant temperature of 70 °C for 3 h, then take out the cordierite, rinse it with deionized water 3-4 times, then dry the cordierite at 120 °C for 6 h, and finally calcine the cordierite at 400 °C for 3 h to obtain the pretreated cordierite support;

[0152] (2) Weigh 7.3 g of copper nitrate trihydrate, 8.68 g of cerium nitrate hexahydrate, and 7.1 g of lanthanum chloride hexahydrate in a mortar and mix them mechanically by grinding, then calcine them at 450 °C for 4 h to obtain the active component powder, denoted as CuO-CeO2-La2O3;

[0153] (3) Weigh 4.25 g of the active component powder, 8.5 g of acidic silica sol, 3 g of polyethylene glycol, and 9.25 g of deionized water to prepare a hyper-dispersion solution. Immerse the pretreated cordierite support in the coating solution at 30 °C for 0.5 h, then take it out, drain the excess coating solution in the pores, and dry it at 120 °C for 6 h. Finally, calcine it at 450 °C for 4 h to obtain cordierite-CuO-CeO2-La2O3;

[0154] (4) Take 0.6 ml of ruthenium chloride solution with a mass concentration of 10 mg / ml in a beaker, then use 4 wt% ammonia water to adjust the pH of the solution to 9 and coat it on the surface of cordierite-active component. Dry it at 120 °C for 5 h to obtain cordierite-CuO-CeO2-La2O3-Ru;

[0155] (5) Take 0.7 ml of sodium chloroaurate solution with a mass concentration of 10 mg / ml in a beaker, then coat it on the surface of cordierite-MnO2-Co3O4-CeO2-Ru, and dry it at 120 °C for 5 h. Finally, calcine it at 500 °C for 4 h to obtain the final finished catalyst cordierite-CuO-CeO2-La2O3-RuO2-Au2O3.

[0156] Example 4

[0157] This example provides a preparation method and application of a dual-interface functional site highly sulfur- and water-vapor-resistant CO oxidation catalyst, including the following steps:

[0158] (1) Immerse 10 g of cordierite in 10 wt% oxalic acid solution, treat it at a constant temperature of 70 °C for 3 h, then take out the cordierite and rinse it with deionized water 3-4 times. Then dry the cordierite at 120 °C for 6 h, and finally calcine the cordierite at 400 °C for 3 h to obtain the pretreated cordierite support;

[0159] (2) Take 7.3 g of copper nitrate trihydrate, 8.68 g of cerium nitrate hexahydrate, and 6.9 g of manganese acetate in a mortar and mix and grind them mechanically. Then calcine them at 450 °C for 3 h to obtain the active component powder, denoted as CuO-CeO2-MnO2;

[0160] (3) Take 5.25 g of the active component powder, 8 g of acidic silica sol, 3 g of polyethylene glycol, and 8.75 g of deionized water to prepare an ultra-dispersed solution. Immerse the pretreated cordierite support in the coating solution at 30 °C for 0.5 h, then take it out and drain the excess coating solution in the pores, and dry it at 120 °C for 6 h. Finally, calcine it at 500 °C for 4 h to obtain cordierite-CuO-CeO2-MnO2;

[0161] (4) Take 0.6 ml of chloroplatinic acid solution with a mass concentration of 8 mg / ml in a beaker, then use 4 wt% ammonia water to adjust the pH of the solution to 10 and coat it on the surface of cordierite-CuO-CeO2-MnO2. Dry it at 120 °C for 5 h to obtain cordierite-CuO-CeO2-MnO2-Pt;

[0162] Take 0.6 ml of palladium nitrate solution with a mass concentration of 8 mg / ml in a beaker, then coat it on the surface of cordierite-Co3O4-CeO2-CuO-Au, dry it at 120 °C for 5 h, and finally calcine it at 450 °C for 4 h to obtain the final finished catalyst cordierite-CuO-CeO2-MnO2-PtO2-PdO.

[0163] Example 5

[0164] This example provides a preparation method and application of a dual-interface functional site highly sulfur- and water-vapor-resistant CO oxidation catalyst, including the following steps:

[0165] (1) Immerse 10 g of cordierite in 15 wt% oxalic acid solution, keep it at a constant temperature of 80 °C for 2 h, then take out the cordierite and rinse it with deionized water 3 - 4 times, then dry the cordierite at 120 °C for 6 h, and finally calcine the cordierite at 450 °C for 3 h to obtain a pretreated cordierite support;

[0166] (2) Take 4.76 g of cobalt chloride hexahydrate and 17.32 g of lanthanum nitrate hexahydrate in a mortar and mix and grind them mechanically, then calcine them at 500 °C for 3 h to obtain an active component powder, denoted as Co3O4-La2O3;

[0167] (3) Take 5.25 g of the active component powder, 8.5 g of acidic silica sol, 3 g of polyethylene glycol and 8.75 g of deionized water to prepare an ultra-dispersed solution, immerse the pretreated cordierite support in the coating solution at 30 °C for 0.5 h, then take it out and drain the excess coating solution in the pores, and then dry it at 120 °C for 6 h, and finally calcine it at 450 °C for 4 h to obtain cordierite-Co3O4-La2O3;

[0168] (4) Take 0.9 ml of platinum nitrate solution with a mass concentration of 4 mg / ml in a beaker, then adjust the pH of the solution to 10 with 4 wt% ammonia water and coat it on the surface of cordierite-Co3O4-La2O3, dry it at 120 °C for 5 h to obtain cordierite-Co3O4-La2O3-Pt;

[0169] (5) Take 0.7 ml of ruthenium chloride solution with a mass concentration of 10 mg / ml in a beaker, then coat it on the surface of cordierite-Co3O4-La2O3-Pt, dry it at 120 °C for 5 h, and finally calcine it at 400 °C for 4 h to obtain the final finished catalyst cordierite-Co3O4-La2O3-PtO2-RuO2.

[0170] Example 6

[0171] This example provides a preparation method and application of a dual-interface functional site highly sulfur- and water-vapor-resistant CO oxidation catalyst, including the following steps:

[0172] (1) Immerse 10 g of cordierite into 30 wt% oxalic acid solution, keep it at a constant temperature of 60 °C for 2 h, then take out the cordierite and rinse it with deionized water 3 - 4 times, then dry the cordierite at 120 °C for 6 h, and finally calcine the cordierite at 400 °C for 3 h to obtain the pretreated cordierite support;

[0173] (2) Take 4.98 g of cobalt acetate tetrahydrate, 7.25 g of copper nitrate trihydrate, and 7.07 g of lanthanum nitrate hexahydrate, mechanically mix and grind them in a mortar, and then calcine them at 450 °C for 3 h to obtain the active component powder, denoted as Co3O4 - CuO - La2O3;

[0174] (3) Take 3.9 g of the active component powder, 7.5 g of acidic silica sol, 3.5 g of polyethylene glycol, and 10.1 g of deionized water to prepare an ultra - dispersed solution. Immerse the pretreated cordierite support into the coating solution at 30 °C for 0.5 h, then take it out, drain the excess coating solution in the pores, and dry it at 120 °C for 6 h. Finally, calcine it at 400 °C for 4 h to obtain cordierite - Co3O4 - CuO - La2O3;

[0175] (4) Take 0.8 ml of sodium chloroaurate solution with a mass concentration of 10 mg / ml in a beaker, then adjust the pH of the solution to 10 with 4 wt% ammonia water and coat it on the surface of cordierite - Co3O4 - CuO - La2O3, and dry it at 120 °C for 5 h to obtain cordierite - Co3O4 - CuO - La2O3 - Au;

[0176] (5) Take 0.6 ml of platinum nitrate solution with a mass concentration of 4 mg / ml in a beaker, then coat it on the surface of cordierite - Co3O4 - CeO2 - Au, dry it at 120 °C for 5 h, and finally calcine it at 500 °C for 4 h to obtain the final product catalyst cordierite - Co3O4 - CuO - La2O3 - Au2O3 - PtO2.

[0177] Example 7

[0178] This example provides a preparation method and application of a dual - interface functional - site high - sulfur - and - water - vapor - resistant CO oxidation catalyst, including the following steps:

[0179] (1) Immerse 10 g of monolithic cordierite into 10 wt% oxalic acid solution, keep it at a constant temperature of 70 °C for 3 h, then take out the cordierite and rinse it with deionized water 3 - 4 times, then dry the cordierite at 120 °C for 6 h, and finally calcine the cordierite at 400 °C for 3 h to obtain the pretreated cordierite support;

[0180] (2) Take 7.3 g of copper nitrate trihydrate, 8.68 g of cerium nitrate hexahydrate, and 7.1 g of lanthanum chloride hexahydrate, mechanically mix and grind them in a mortar, and then calcine them at 450 °C for 4 h to obtain the active component powder, denoted as CuO - CeO2 - La2O3;

[0181] (3) Weigh 4.25 g of the active component powder, 8.5 g of acidic silica sol, 3 g of polyethylene glycol, and 9.25 g of deionized water to prepare a hyperdispersed solution. Immerse the pretreated cordierite support in the coating solution at 30 °C for 0.5 h, then take it out, drain the excess coating solution in the pores, dry it at 120 °C for 6 h, and finally calcine it at 450 °C for 4 h to obtain cordierite-CuO-CeO2-La2O3;

[0182] (4) Take 0.6 ml of a palladium nitrate solution with a mass concentration of 8 mg / ml in a beaker, then adjust the pH of the solution to 9 using 4 wt% ammonia water and coat it on the surface of cordierite-active component. Dry it at 120 °C for 5 h to obtain cordierite-CuO-CeO2-La2O3-Pd;

[0183] (5) Take 0.7 ml of a sodium chloroaurate solution with a mass concentration of 10 mg / ml in a beaker, then coat it on the surface of cordierite-MnO2-Co3O4-CeO2-Pd, dry it at 120 °C for 5 h, and finally calcine it at 500 °C for 4 h to obtain the final finished catalyst cordierite-CuO-CeO2-La2O3-PdO-Au2O3.

[0184] Comparative Example 1

[0185] In this comparative example, 10 wt% oxalic acid was not used in step (1) of Example 1.

[0186] Comparative Example 2

[0187] In this comparative example, cobalt sulfate hexahydrate and copper nitrate trihydrate were not added in step (2) of Example 1.

[0188] Comparative Example 3

[0189] In this comparative example, manganese acetate and copper nitrate trihydrate were not added in step (2) of Example 1.

[0190] Comparative Example 4

[0191] In this comparative example, the active component powder was not added in step (3) of Example 1.

[0192] Comparative Example 5

[0193] In this comparative example, acidic silica sol was not added in step (3) of Example 1.

[0194] Comparative Example 6

[0195] In this comparative example, polyethylene glycol was not added in step (3) of Example 1.

[0196] Comparative Example 7

[0197] This comparative example is that the palladium chloride co-active component was not added in step (4) of Example 1.

[0198] Comparative Example 8

[0199] This comparative example is that the ruthenium chloride co-active component was not added in step (5) of Example 1.

[0200] Comparative Example 9

[0201] This comparative example is that ammonia water was not used to adjust the pH in step (4) of Example 1.

[0202] Comparative Example 10

[0203] This comparative example is that calcination at 500 °C was not carried out in step (5) of Example 1.

[0204] Catalyst activity test: 6 g of the finished catalyst was taken in a fixed-bed stainless steel tube reactor with an inner diameter of 17 mm for the stainless steel tube. The simulated flue gas consisted of CO, O2 and N2, where CO was 4000 ppm, O2 was 10%, and the space velocity was 10000 h -1 , the test temperature was 150 °C, and the reaction tail gas was detected with a German Testo-350 flue gas analyzer.

[0205] Catalyst sulfur and water vapor resistance performance test: 100 ppm SO2 and 20 vol% water vapor were additionally added to the simulated flue gas. The test temperature was 225 °C, and other test conditions remained unchanged. The reaction tail gas was detected with a German Testo-350 flue gas analyzer.

[0206] Catalyst sulfur and water vapor resistance performance test under high sulfur concentration: The test temperature was 250 °C, and the volume space velocity (GHSV) was 7500 h -1 , the flue gas conditions were 4000 ppm CO, 10 (vol)% O2, 4500 ppm SO2, 5 (vol)% H2O, and the reaction tail gas was detected with a German Testo-350 flue gas analyzer.

[0207] Refer to Table 1. Table 1 shows the test results of the catalysts prepared in Example 1 and the comparative examples of the present invention.

[0208] Table 1

[0209]

[0210]

[0211] Note: The sulfur and water vapor resistance performance test values and the sulfur and water vapor resistance performance test values under high sulfur concentration are the stable activities of the catalysts after 48 h of testing.

[0212] As can be seen from the data in the above table, the present invention provides a method for the large-scale preparation of a dual-interface functional-site highly sulfur-resistant and water-vapor-resistant CO oxidation catalyst in Examples 1 to 7. In this catalyst preparation method, cordierite is used as the carrier, and a monolithic CO oxidation catalyst with dual-interface functional sites is prepared by a solution super-dispersion impregnation process. The dual-interface functional sites have a stronger affinity for CO, which can enhance the adsorption of CO on the catalyst surface and inhibit the adsorption process of SO2. After the adsorption process of CO on the catalyst surface is completed, the lattice oxygen in the inner-layer active component is used to complete the CO oxidation process. Under this synergistic effect, it not only has high and stable CO oxidation ability, but also has excellent sulfur and water-vapor poisoning resistance performance.

[0213] Examples 1 to 2 show that the present invention can regulate the catalytic activity of the catalyst by controlling the types of non-precious metal active components. Examples 2 to 3 show that the present invention can regulate the catalytic activity and sulfur and water-vapor resistance performance of the catalyst by controlling the types of noble metal co-active components.

[0214] Comparative Examples 1 and 5 and Comparative Example 6 illustrate that the use of oxalic acid for the pretreatment of cordierite and the addition of acidic silica sol and polyethylene glycol during the non-precious metal coating process will affect the performance of the catalyst. This is mainly because the oxalic acid treatment can remove the impurities on the surface of cordierite and enrich its pore structure, while the acidic silica sol can enhance the bonding between the active component and the cordierite carrier, and polyethylene glycol acts as a dispersant, all of which are beneficial to the loading of the active component, and thus better play the role of CO catalytic oxidation.

[0215] Comparative Examples 2 to 4 illustrate that the non-precious metal active component plays an important role in the whole synergistic catalytic process. When using a single or no inner-layer non-precious metal, after the adsorption process of CO on the catalyst surface is completed, the lattice oxygen in the inner-layer active component cannot be used to complete the CO oxidation process. Therefore, the catalytic activity is reduced, and at the same time, it will also affect the sulfur and water-vapor resistance performance of the catalyst.

[0216] Comparative Example 7 shows that the addition of noble metal co-active components is beneficial to the improvement of the catalyst performance, keeping it at a high catalytic activity and relatively high sulfur and water-vapor resistance performance level.

[0217] Comparative Example 8 shows that the noble metal co-active components have a great influence on the sulfur and water-vapor resistance performance of the catalyst. During the reaction process, the adsorption of SO2 on the catalyst surface cannot be inhibited, causing the catalyst to be continuously poisoned and inactivated, and finally maintaining a relatively low catalytic performance level.

[0218] Comparative Examples 9-10 illustrate that adjusting the pH of the promoter solution and the calcination process in step (5) are beneficial to improving the catalyst performance. This is mainly because adjusting the pH of the promoter solution can control the particle size distribution of the components on the catalyst surface, promote the construction of dual-interface functional sites, and calcination plays an activating role on the promoter and anti-sulfur components, thereby affecting their catalytic activity and anti-sulfur and anti-water vapor performance.

[0219] The above provides a detailed introduction to a dual-interface functional site highly anti-sulfur and anti-water vapor CO oxidation catalyst and its large-scale preparation method and application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention, including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those of ordinary skill in the art in the technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The protection scope of this invention patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the literal description of the claims, or if they include equivalent structural elements that have no substantial difference from the literal description of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A CO oxidation catalyst, characterized in that, Comprising: A carrier, and an active component and a promoter component compounded on the carrier; The carrier is a cordierite carrier; The active component is two or more of CuO, MnO₂, Co₃O₄, CeO₂ and La₂O₃; The promoter component is one or more of Pd, Au, Pt and Ru.

2. The CO oxidation catalyst according to claim 1, wherein The CO oxidation catalyst is specifically a CO oxidation catalyst with dual interface functional sites; The active component accounts for 5% - 25% of the total mass of the catalyst; The promoter component accounts for 0.01% - 0.1% of the total mass of the catalyst; The CO oxidation catalyst includes a high sulfur and water vapor resistant CO oxidation catalyst.

3. The CO oxidation catalyst according to claim 1, wherein The carrier accounts for 74.9% - 94.99% of the total mass of the catalyst; The carrier has a structure combining a non-noble metal active component layer and a noble metal promoter component layer; The non-noble metal active component layer is the inner layer of the catalyst and the outer layer of the noble metal promoter component compounded on the inner layer of the catalyst.

4. A method for preparing a CO oxidation catalyst according to any one of claims 1 to 3, characterized in that, Including the following steps: 1) After subjecting cordierite to acid treatment and the first calcination, pretreated cordierite is obtained; The active component precursor is calcined for the second time to obtain an active component powder; 2) The pretreated cordierite obtained in the above step is placed in a mixed solution of an active component powder, a binder, a dispersant and water for the first impregnation, and then after the third calcination, cordierite loaded with the active component is obtained; 3) After adjusting the pH value of the promoter component precursor solution, the cordierite loaded with the active component obtained in the above step is placed therein for the second impregnation, and then after the fourth calcination, a CO oxidation catalyst is obtained.

5. The preparation method according to claim 4, characterized in that, The acid treatment is specifically carried out by immersing in an acid solution; The acid solution includes hydrochloric acid and / or oxalic acid solution; The mass concentration of the acid solution is 10% - 30%; The temperature of the acid treatment is 60 - 100°C; The time of the acid treatment is 1 - 4 h.

6. The preparation method according to claim 4, characterized in that, The temperatures of the first calcination, the second calcination, the third calcination and the fourth calcination are each independently selected from 300 - 600°C; The times of the first calcination, the second calcination, the third calcination and the fourth calcination are each independently selected from 4 - 8 h; The active component precursor includes one or more of acetates, nitrates, sulfates, carbonates, chlorides and oxides of the active component.

7. The preparation method according to claim 4, characterized in that, The binder includes an acidic silica sol solution; The dispersant includes polyethylene glycol; The mass ratio of the active component powder to SiO₂ in the acidic silica sol solution is (1 - 2.5):(0.3 - 1.2); The mass ratio of the active component powder to the dispersant is (1 - 2.5):(0.5 - 1).

8. The preparation method according to claim 4, characterized in that, The temperatures of the first impregnation and the second impregnation are each independently selected from 20 - 60°C; The times of the first impregnation and the second impregnation are each independently selected from 0.1 - 2 h; The promoter component precursor includes one or more of palladium chloride, palladium nitrate, sodium chloroaurate, platinum nitrate, chloroplatinic acid and ruthenium chloride; The pH value is adjusted to 8 - 10.

9. The preparation method according to claim 4, characterized in that, When the promoter component is multiple, step 3) is specifically the following steps: After adjusting the pH value of the first promoter precursor solution, cordierite loaded with the active component is placed therein for the second impregnation and then dried, and then placed in the second promoter precursor solution for the third impregnation and then dried, and so on. Finally, after the fourth calcination, a CO oxidation catalyst is obtained; The temperature of the drying is 60-120 °C; The time of the drying is 2-6 h.

10. Application of the CO oxidation catalyst according to any one of claims 1-3 or the CO oxidation catalyst prepared by the preparation method according to any one of claims 4-9 in treating waste gas containing sulfur, water vapor and carbon.

Images