Pt-based catalyst with (1x2)-(110) surface structure for catalyzing CO oxidation and preparation method thereof

Abstract

The application provides a Pt-based catalyst with (1x2)-(110) surface structure for catalyzing CO oxidation and a preparation method thereof. The preparation method of the catalyst is as follows: an oxide carrier and a platinum source are ground and loaded, and after heat treatment under a specific atmosphere, Pt-carrier powder is obtained; then the Pt-carrier powder is calcined with a mixed gas of CO and O2 at a certain temperature for a certain time, so that a Pt-based catalyst with Pt surface with (1x2) structure for catalyzing CO oxidation is prepared in situ. The Pt-based catalyst has the following characteristics: the (1x2) structure of the (110) surface of Pt nanoparticles changes the gas adsorption behavior, and establishes double active sites respectively beneficial to adsorption of O2 and desorption of CO, so that the problem of 'CO poisoning' in the Pt catalytic reaction can be significantly relieved during catalytic oxidation of CO. Compared with other catalysts with other structures, the Pt-based catalyst with the (1x2) special structure has more excellent CO catalytic oxidation activity, and has more practical application value.

Description

Technical Field

[0001] This invention relates to the preparation and application of a catalyst, specifically a Pt-based catalyst with a (1×2)-(110) surface structure that is highly efficient for catalyzing CO oxidation in industries such as chemical and coal, and its preparation method. Background Technology

[0002] Incomplete combustion of fossil fuels and vehicle exhaust both emit large amounts of colorless, odorless, and toxic CO gas. Furthermore, fires also produce significant amounts of CO gas, seriously threatening the lives of those escaping and those rescuing. Therefore, CO oxidation plays a crucial role in gas purification, CO gas detectors, breathing gas purification devices, eliminating trace amounts of CO in closed systems, and air pollution control, especially in vehicle exhaust control.

[0003] The most important external purification device installed inside a car's exhaust system is the three-way catalytic converter. When hot exhaust gases pass through this device, the purifying agent in the catalytic converter causes harmful gases such as CO, hydrocarbons, and nitrogen oxides in the exhaust to undergo certain oxidation-reduction chemical reactions, transforming them into harmless carbon dioxide, water, and nitrogen through oxidation and reduction. This conversion of the three harmful gases into harmless gases purifies the car's exhaust.

[0004] Currently, the most widely used catalysts for CO catalytic oxidation are precious metal catalysts such as platinum and palladium, transition metal oxide catalysts, and transition metal alloy catalysts. Transition metal oxide catalysts have lower costs, but their structures are unstable and they are prone to deactivation at high temperatures during use. Transition metal alloy catalysts have better structural stability, but their preparation is complex and their costs remain high. In contrast, precious metal catalysts such as platinum and palladium are simple to prepare and have excellent catalytic activity, stability, and selectivity. However, during use, CO strongly adsorbs onto the Pt surface, causing poisoning and reducing catalytic activity, thus increasing the cost of using these catalysts.

[0005] Therefore, based on the actual application requirements of CO oxidation technology, it is of great significance to improve the CO poisoning resistance of Pt-based catalysts, develop highly active CO oxidation catalysts, and further reduce the cost of CO oxidation catalysts. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the technical problem to be solved by this invention is to provide a method for preparing a Pt-based catalyst with a (1×2)-(110) surface active structure for highly efficient CO oxidation. The applicant has discovered that introducing a CO / O2 mixed gas into supported Pt nanoparticles can in situ construct a Pt-based catalyst with a (1×2)-(110) active structure on the Pt surface; by controlling the temperature and manipulating the CO / O2 gas ratio, the Pt surface site structure can be flexibly controlled under a wide range of conditions to construct a Pt-based catalyst with a (1×2)-(110) active structure; the microstructure of the obtained Pt-based catalyst and the precise atomic structure of the Pt particle surface were determined by TEM, and the CO oxidation performance of the Pt-based catalyst was characterized by testing at a certain temperature, thus proving that the Pt-based catalyst with the special (1×2)-(110) structure can catalytically oxidize CO at temperatures as low as 378 K, and greatly improves the efficiency of CO catalytic oxidation. Based on supported Pt nanoparticles, this invention proposes for the first time to construct a Pt-based catalyst with a (1×2)-(110) surface structure that can efficiently catalyze the oxidation of CO by calcining with a mixed gas of CO and O2 at a certain temperature. This is achieved by in-situ activation induced by the reaction atmosphere. The catalyst is simple, convenient, highly controllable, and practical, and can be widely used in industrial production.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] A method for preparing a Pt-based catalyst with a (1×2)-(110) surface structure for catalytic CO oxidation is disclosed. First, an inert oxide support is obtained via a solvothermal method. A certain amount of Pt nanoparticles are then loaded onto the surface of the prepared inert oxide support. The support is pretreated by heating at a certain temperature, followed by calcination with a mixed gas of CO and O2 for a certain period. Activation is then induced under a CO and O2 reaction atmosphere, causing the (110) surface of the Pt nanoparticles to form a (1×2) active structure. The (1×2)-(110) active structure constructed in situ on the surface of supported Pt nanoparticles exhibits excellent catalytic performance in CO oxidation.

[0009] As a preferred technical solution of the present invention, the preparation method of the Pt-based catalyst with a (1×2)-(110) surface structure for catalytic CO oxidation specifically includes the following steps:

[0010] (1) Loading of Pt nanoparticles: The oxide support and platinum source with a mass ratio of 15:1-5:1 were ground in a mortar for 5-60 min to make them uniformly mixed; then the ground mixture was transferred to a crucible and placed in a muffle furnace and heated to 373-773 K at a heating rate of 1K / min-10K / min; the mixture was first heat-treated in an oxygen atmosphere for 0.5-6 h, and then cooled to room temperature; then it was heated to 373-773 K in a hydrogen atmosphere at a heating rate of 1K / min-10K / min, and the mixture was heat-treated in a hydrogen atmosphere for 0.5-6 h, and then cooled to room temperature to obtain the oxide loaded with Pt nanoparticles, which was ready for use.

[0011] (2) Constructing an active structure (1×2) in situ on the surface of Pt nanoparticles: The oxide of Pt nanoparticles loaded in step (1) above is pretreated in the temperature range of 300K-1000K, the heating rate is 1-100K / min, and the pretreatment time is 1-600min; after the pretreatment is completed, a mixture of CO and O2 gas is introduced and calcined in the mixed atmosphere for 0.05-600min to obtain a Pt-based catalyst with a (1×2)-(110) surface structure.

[0012] The method for preparing a Pt-based catalyst with a (1×2)-(110) surface structure for catalytic CO oxidation according to the present invention further includes the following preferred embodiments.

[0013] As a preferred embodiment, the oxide support described above is an inert oxide support, which includes titanium dioxide, cerium dioxide, and silicon dioxide.

[0014] As a preferred embodiment, the oxide support described in step (1) above has a size of 1nm-100um and a morphology of cube, octahedron, sphere or irregular sheet.

[0015] As a preferred embodiment, the loading of Pt nanoparticles in step (1) above, wherein the platinum source is platinum acetylacetonate or platinum nanocubes, the grinding time is 5-60 min, and the size of the Pt nanoparticles is 1 nm-1000 nm.

[0016] As a preferred embodiment, the Pt-based catalyst with the desired (1×2)-(110) surface structure can be obtained by calcining with a mixed gas of CO and O2 in step (2) above. The pretreatment temperature is 300K-1000K, the heating rate is 1-100K / min, and the pretreatment time is 1-600min. The gas ratio of CO and O2 is 0.001-10:1, the concentration of CO gas is 1%-100%, the concentration of O2 gas is 1%-100%, the calcination temperature is 300K-1000K, and the calcination time is 0.05-600min. By adjusting the gas ratio of CO and O2 and the calcination temperature, the change of the catalyst surface structure can be controlled in situ by inducing activation under the reaction atmosphere without changing the catalyst.

[0017] A Pt-based catalyst with a (1×2)-(110) surface structure for catalyzing CO oxidation was prepared using the method described above. It can serve as a highly active catalyst for CO oxidation within a temperature range of 378K-1073K. The (1×2)-(110) structure in the Pt-based catalyst refers to the (1×2) structure on the (110) surface of Pt nanoparticles. This structure provides dual active sites that facilitate both O2 adsorption and CO desorption, resulting in a higher O coverage on the (1×2)-(110) surface of the Pt-based catalyst. This alleviates the "CO poisoning" problem in Pt catalytic reactions and thus promotes CO oxidation activity.

[0018] The Pt-based catalyst with a (1×2)-(110) surface structure allows for the surface structure regulation of Pt nanoparticles and CO catalytic oxidation to be carried out in the same atmosphere, thus eliminating the need for additional reaction atmosphere conversion.

[0019] Compared with existing technologies, the beneficial effects of the present invention are as follows:

[0020] This invention utilizes supported Pt nanoparticles as a base, and through methods such as calcination with a mixed gas of CO and O2 at a certain temperature, a highly efficient Pt-based catalyst with a (1×2)-(110) surface structure for CO oxidation is obtained through in-situ activation induced by the reaction atmosphere. This invention possesses the following obvious and substantial features and significant advantages:

[0021] This invention proposes for the first time a method of calcining with a mixture of CO and O2 at a certain temperature to construct an in-situ (1×2)-(110) structure on the surface of supported Pt nanoparticles by inducing activation in a reaction atmosphere. This method is simple, convenient, easy to operate, highly controllable, and highly practical, making it suitable for industrial production.

[0022] The (1×2)-(110) structure constructed in situ on the surface of supported Pt nanoparticles by the method of this invention is the active component of the catalyst. When applied to the oxidation of CO, the (1×2) structure on the surface of the Pt nanoparticles (110) alters the gas adsorption behavior and establishes dual active sites that are conducive to the adsorption of O2 and the desorption of CO, respectively. This results in a higher O coverage on the surface of the (1×2)-(110) structure in the Pt-based catalyst, which can alleviate the "CO poisoning" problem in the Pt catalytic reaction and thus promote the CO catalytic activity. At the same time, under the same conditions, the amount of Pt-based catalyst with this (1×2)-(110) surface structure required to achieve the same catalytic activity in CO oxidation is reduced by at least half, which greatly reduces the cost of using the catalyst.

[0023] The method of this invention can flexibly control the changes in the Pt surface site structure under a wide range of conditions by adjusting the temperature and manipulating the CO / O2 gas ratio, and construct Pt-based catalysts with (1×2)-(110) active structures, without being limited by external factors such as the type, size, and crystal face of the support; and can reduce the CO oxidation reaction temperature of the supported Pt catalyst with (1×2)-(110) structure to as low as 378K, which greatly improves the efficiency of catalytic CO oxidation.

[0024] The method of this invention is simple, easy to implement, and has significant economic benefits. Attached Figure Description

[0025] Figure 1 The images shown are transmission electron microscope (TEM) images of the Pt-TiO2 catalyst prepared in Example 1 before CO / O2 calcination treatment, wherein: (a) is a TEM image of Pt nanoparticles with a (1×1)-(110) structure supported on a titanium dioxide support; (b) is a magnified TEM image of a single Pt nanoparticle in Figure (a); and (c) is a magnified TEM image of the (1×1) structure on the surface of the (110) Pt nanoparticles in Figure (b).

[0026] Figure 2 The images shown are transmission electron microscope (TEM) images of the Pt-TiO2 catalyst prepared in Example 1 after CO / O2 calcination treatment, where: (a) is a TEM image of Pt nanoparticles with a (1×2)-(110) structure supported on a titanium dioxide support; (b) is a magnified TEM image of a single Pt nanoparticle in Figure (a); and (c) is a magnified TEM image of the (1×2) structure on the surface of the (110) Pt nanoparticles in Figure (b).

[0027] Figure 3The images shown are transmission electron microscope (TEM) images of the Pt-TiO2 catalyst prepared in Example 2 before and after CO / O2 calcination treatment. (a) is a TEM image of Pt nanoparticles with a (1×1)-(110) structure supported on a titanium dioxide support; (b) is a magnified TEM image of a single Pt nanoparticle after CO / O2 treatment in Figure (a); and (c) is a magnified TEM image of the (1×2) structure on the surface of the (110) Pt nanoparticles in Figure (b).

[0028] Figure 4 The graph shows the performance of the Pt-based catalyst prepared in Example 1 applied to CO oxidation.

[0029] Figure 5 The graph shows the performance of the Pt-based catalyst prepared in Example 3 for CO oxidation.

[0030] Figure 6 The graph shows the performance of the Pt-based catalyst prepared in Example 4 applied to CO oxidation. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] Example 1

[0033] A method for preparing a Pt-based catalyst with a (1×2)-(110) surface structure for catalytic CO oxidation. The preparation method includes the following steps:

[0034] (1) Loading of Pt nanoparticles: Titanium dioxide octahedral support and platinum acetylacetonate in a mass ratio of 10:1 were ground in a mortar for 30 min, and then heated to 573 K at a heating rate of 10 K / min. The mixture was first heat-treated in an oxygen atmosphere for 3 h, and then heat-treated in a hydrogen atmosphere for 3 h to obtain titanium dioxide loaded with Pt nanoparticles.

[0035] (2) An active structure of (1×2) is constructed in situ on the surface of the loaded Pt nanoparticles. The Pt / TiO2 obtained in step (1) above is pretreated at 373K with a heating rate of 10K / min and a pretreatment time of 5min. After the pretreatment is completed, a mixture of CO and O2 gas in a specific ratio is introduced and calcined for 0.1min under the mixed atmosphere to obtain a Pt / TiO2 catalyst with a special structure of (1×2) on the (110) surface of the Pt nanoparticles.

[0036] The volume ratio of CO to O2 was 0.08:1, the concentration of CO was 5%, the concentration of O2 was 5%, the temperature was 378K, and the loading of Pt was 30%.

[0037] In this embodiment, Pt nanoparticles are first loaded onto a titanium dioxide support surface, and then calcined at a certain temperature using a mixed gas of CO and O2. This induces in-situ activation and construction of a (1×2)-(110) structure on the surface of the supported Pt nanoparticles using the reaction atmosphere. This method overcomes the limitations of traditional methods that require constructing a (1×2) structure on a clean Pt single-crystal surface, expanding the material's application range and making its use in catalytic reactions possible. The method is simple, convenient, easy to operate, and highly controllable. In this embodiment, during the in-situ construction of the (1×2)-(110) active structure on the surface of supported Pt nanoparticles, the surface structure regulation of Pt nanoparticles and CO catalytic oxidation can be carried out in the same atmosphere as the mixed gas of CO and O2, without the need for additional reaction atmosphere conversion. The experimental atmosphere for regulating the surface structure changes of Pt nanoparticles can all originate from the CO catalytic oxidation reaction atmosphere itself. The (1×2)-(110) structure constructed in situ on the surface of supported Pt nanoparticles in this embodiment is a key component of the catalyst. When applied to the oxidation of CO, the (1×2) structure on the surface of the Pt nanoparticles (110) alters the gas adsorption behavior and establishes dual active sites that facilitate the adsorption of O2 and the desorption of CO, respectively. This results in a higher O coverage on the surface of the (1×2)-(110) structure in the Pt-based catalyst, which can alleviate the "CO poisoning" problem in the Pt catalytic reaction and thus promote the CO catalytic activity.

[0038] The Pt structure on the surface of titanium dioxide loaded with Pt nanoparticles, obtained before and after CO / O2 heat treatment in this embodiment, was characterized using transmission electron microscopy (TEM). The TEM results are as follows: Figure 1 (a)(b)(c) and Figure 2 As shown in (a)(b)(c).

[0039] Pt / TiO2 nanoparticles obtained before CO / O2 heat treatment, such as Figure 1 As shown in (a), the Pt particle size is mainly concentrated around 10 nm, and the magnified structure of a single Pt nanoparticle is as follows. Figure 1 As shown in (b), the surface of the Pt particles (110) has a (1×1) structure, which can also be seen from... Figure 1 (c) This was demonstrated in the characterization of a finer (1×1) structure on the Pt(110) surface. The Pt / TiO2 nanoparticles were calcined in a CO / O2 mixed atmosphere, and the resulting Pt / TiO2 nanoparticles after CO / O2 heat treatment were as follows: Figure 2 As shown in (a), the Pt particle size is still mainly concentrated around 10 nm, and no changes such as sintering are observed in the Pt particles. The magnified structure of a single Pt nanoparticle is shown in Figure 1. Figure 2As shown in (b), activation induced by a CO / O2 mixed atmosphere allows for the in-situ construction of a (1×2) structure on the surface of Pt particles (110). This can also be seen from... Figure 2 (c) This is demonstrated in the finer (1×2) structural characterization of the Pt(110) surface.

[0040] In the CO oxidation process, one CO molecule occupies one empty surface site for adsorption, while one O2 molecule occupies two empty surface sites. This makes the adsorption competitiveness of O2 on the catalytic surface weaker than that of CO. On the (1×1)-(110) surface, only low coordination sites with a coordination number (CN) of 7 are favorable for the adsorption of CO and O2. Once the CO coverage is high, this surface becomes an inhibitor of O2 adsorption, which is the so-called "CO poisoning" effect in CO oxidation. After the Pt particle surface is reconstructed, the (1×2) structure of the (110) surface provides additional adsorption sites consisting of one CN-7 site and an adjacent CN-9 site. The weak adsorption of CO on the CN-9 site, which only adsorbs O2, can prevent CO poisoning at the site. This leads to a higher O coverage on the (1×2)-(110) reconstructed surface, which in turn promotes the CO catalytic oxidation activity and allows the reaction temperature of CO oxidation to be as low as 378K. The results of CO catalytic oxidation performance are as follows: Figure 4 As shown.

[0041] Example 2

[0042] In this embodiment, a method for preparing a Pt-based catalyst with a (1×2)-(110) surface structure for catalytic CO oxidation includes the following steps:

[0043] (1) Loading of Pt nanoparticles: Titanium dioxide octahedral support and platinum acetylacetonate in a mass ratio of 10:3 were ground in a mortar for 30 min, and then heated to 573 K at a heating rate of 10 K / min. The mixture was first heat-treated in an oxygen atmosphere for 3 h, and then heat-treated in a hydrogen atmosphere for 3 h to obtain titanium dioxide loaded with Pt nanoparticles.

[0044] (2) An active structure of (1×2) is constructed in situ on the surface of the loaded Pt nanoparticles. The Pt / TiO2 obtained in step (1) above is pretreated at 373K with a heating rate of 10K / min and a pretreatment time of 5min. After the pretreatment is completed, a mixture of CO and O2 gas in a specific ratio is introduced and calcined for 0.1min under the mixed atmosphere to obtain a Pt / TiO2 catalyst with a special structure of (1×2) on the (110) surface of the Pt nanoparticles.

[0045] The volume ratio of CO to O2 is 1:1, the concentration of CO is 5%, the concentration of O2 is 5%, and the temperature is 473K.

[0046] The prepared Pt / TiO2 nanoparticles, such as Figure 3 As shown in (a), it was calcined in a 1:1 CO / O2 mixed atmosphere. The single Pt nanoparticles obtained after CO / O2 heat treatment are as follows: Figure 3 As shown in (b), activation induced by a 1:1 CO / O2 mixed atmosphere can also lead to the in-situ construction of a (1×2) structure on the surface of Pt particles (110). This can also be seen from... Figure 3 (c) This is demonstrated in the finer (1×2) structural characterization of the Pt(110) surface.

[0047] This embodiment is basically the same as Embodiment 1, except that the ratio of CO to O2 is different.

[0048] Example 3

[0049] In this embodiment, a method for preparing a Pt-based catalyst with a (1×2)-(110) surface structure for catalytic CO oxidation includes the following steps:

[0050] (1) Loading of Pt nanopowder: Cerium dioxide cubic carrier with a mass ratio of 10:1 and pre-prepared 10nm Pt particles were ground in a mortar for 30min. Then, the mixture was heated to 573K at a heating rate of 10K / min. It was first heat-treated in an oxygen atmosphere for 3h and then in a hydrogen atmosphere for 3h to obtain cerium dioxide loaded with Pt nanopowder.

[0051] (2) Construct a (1×2) active structure in situ on the surface of well-loaded Pt nanoparticles, and pretreat the Pt / CeO2 obtained in step (1) above at a temperature of 373K with a heating rate of 10K / min and a pretreatment time of 5min.

[0052] After pretreatment, a mixture of CO and O2 gas in a specific ratio is introduced and calcined for 0.1 min under a mixed atmosphere to obtain a Pt / CeO2 catalyst with a (1×2) special structure on the (110) surface of Pt nanoparticles.

[0053] The volume ratio of CO to O2 was 0.08:1, the concentration of CO was 5%, the concentration of O2 was 5%, the temperature was 423K, and the Pt loading was 3.2%.

[0054] The CO catalytic oxidation performance of the obtained Pt / CeO2 catalyst with the special (1×2)-(110) structure is as follows: Figure 5 As shown.

[0055] This embodiment is basically the same as Embodiment 1, except that the carrier is cerium dioxide.

[0056] Example 4

[0057] In this embodiment, a method for preparing a Pt-based catalyst with a (1×2)-(110) surface structure for catalytic CO oxidation includes the following steps:

[0058] (1) Loading of Pt nanopowder: The silica carrier with a mass ratio of 10:1 and the pre-prepared 10nm Pt particles were ground in a mortar for 30min. Then, the mixture was heated to 573K at a heating rate of 10K / min. It was first heat-treated in an oxygen atmosphere for 3h and then heat-treated in a hydrogen atmosphere for 3h to obtain silica loaded with Pt nanopowder.

[0059] (2) Construct a (1×2) active structure in situ on the surface of well-loaded Pt nanoparticles, and pretreat the Pt / SiO2 obtained in step (1) above at a temperature of 373K with a heating rate of 10K / min and a pretreatment time of 5min.

[0060] After pretreatment, a mixture of CO and O2 gas in a specific ratio is introduced and calcined for 0.1 min under a mixed atmosphere to obtain a Pt / SiO2 catalyst with a (1×2) special structure on the (110) surface of Pt nanoparticles.

[0061] The volume ratio of CO to O2 was 0.08:1, the concentration of CO was 5%, the concentration of O2 was 5%, the temperature was 476K, and the Pt loading was 3.2%.

[0062] The CO catalytic oxidation performance of the obtained Pt / SiO2 catalyst with the special (1×2)-(110) structure is as follows: Figure 6 As shown.

[0063] This embodiment is basically the same as Embodiment 1, except that the carrier is silicon dioxide.

[0064] Figure 4 , Figure 5 , Figure 6The performance of Pt-based catalysts with a (1×2)-(110) surface structure supported on an inert oxide support obtained in Examples 1, 3, and 4 for the catalytic oxidation of CO is described. The reaction conditions for the catalytic oxidation of CO were as follows: the volume ratio of CO to O2 was 0.08:1, the concentration of CO was 5%, the concentration of O2 was 5%, and the reaction temperature was 373K-573K. It can be seen that regardless of the support, the (1×2)-(110) structure on the Pt surface has a significantly enhanced catalytic performance for CO oxidation. Compared with Pt-based catalysts with (1×1)-(110) surface structure, the activation temperature of Pt-based catalysts with (1×2)-(110) surface structure for CO oxidation is greatly reduced, by at least 30-40K. The activation temperature of Pt / TiO2 nanoparticles for CO oxidation can even be as low as 378K, which greatly improves the efficiency of CO catalytic oxidation. At the same time, under the same conditions, the amount of Pt-based catalysts with this (1×2)-(110) surface structure required to achieve the same catalytic activity in CO oxidation is reduced by at least half. It is estimated that structural reconstruction can bring about a 5-50 times increase in catalytic activity per unit active area, which greatly reduces the cost of catalyst use.

[0065] This invention proposes for the first time a calcination treatment using a mixed gas of CO and O2 at a certain temperature. This method utilizes the reaction atmosphere to induce activation and in-situ construction of a (1×2)-(110) structure on the surface of supported Pt particles. This overcomes the limitations of traditional methods that require constructing a (1×2) structure on a clean Pt single-crystal surface, expanding the material's application range and making its use in catalytic reactions possible. During the in-situ construction of the (1×2)-(110) active structure on the surface of Pt particles, the surface structure regulation of Pt nanoparticles and CO catalytic oxidation can be carried out in the same atmosphere as the mixed gas of CO and O2, without the need for additional reaction atmosphere conversion. The experimental atmosphere for regulating the surface structure changes of Pt nanoparticles can all come from the CO catalytic oxidation reaction atmosphere itself. By controlling the temperature and manipulating the CO / O2 gas ratio, the surface site structure of Pt can be flexibly controlled under a wide range of conditions, constructing structures with (1×2)-(110) active structures. The method for constructing a Pt-based catalyst with a 1×2)-(110) active structure is simple, convenient, easy to operate, highly controllable, practical, and suitable for industrial production. The (1×2) structure constructed in situ on the surface of Pt particles (110) is a key component of the catalyst. When applied to the oxidation of CO, this invention found that the (1×2) structure on the surface of Pt nanoparticles (110) changes the gas adsorption behavior and establishes dual active sites that are conducive to O2 adsorption and CO desorption, resulting in a higher O coverage on the surface of the (1×2)-(110) structure in the Pt-based catalyst. This can alleviate the "CO poisoning" problem in the Pt catalytic reaction and thus improve the CO catalytic oxidation efficiency. Under the same conditions, the amount of Pt-based catalyst with this (1×2)-(110) surface structure required to achieve the same catalytic activity in CO oxidation is reduced by at least half, which greatly reduces the cost of using the catalyst.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing a Pt-based catalyst having a (1 x 2)-(110) surface structure which catalyzes oxidation of CO, characterized by, The method comprises the following steps: (1) loading of Pt nanoparticles: grinding the oxide carrier and the platinum source in a mass ratio of 15:1-5:1 in a mortar for 5-60 min to uniformly mix them; then transferring the ground mixture to a crucible and placing it in a muffle furnace, heating it to 373-773 K at a heating rate of 1 K / min-10 K / min; first heat treating the mixture under an oxygen atmosphere for 0.5-6 h, and then cooling it to room temperature; then heating it to 373-773 K at a heating rate of 1 K / min-10 K / min under a hydrogen atmosphere, and heat treating the mixture under a hydrogen atmosphere for 0.5-6 h, and then cooling it to room temperature, to obtain the oxide loaded with Pt nanoparticles, which is ready for use; (2) in-situ construction of (1×2) active structure on the surface of Pt nanoparticles: pre-treating the oxide loaded with Pt nanoparticles obtained in step (1) above at a temperature in the range of 300 K-1000 K at a heating rate of 1-100 K / min for 1-600 min; after the pre-treatment, introducing a CO and O2 mixed gas, and calcining under the mixed atmosphere for 0.05-600 min, to obtain a Pt-based catalyst with a (1×2)-(110) surface structure; in step (2), the gas ratio of CO to O2 is 0.001-10:1, and the calcination temperature under the mixed atmosphere is 300 K-1000 K.

2. The method of producing a Pt-based catalyst having a (1x2)-(110) surface structure for catalyzing oxidation of CO according to claim 1, characterized in that, The oxide carrier is an inert oxide carrier, and the inert oxide carrier includes titanium dioxide, cerium dioxide, and silicon dioxide.

3. The method for preparing a Pt-based catalyst with a (1×2)-(110) surface structure for catalytic CO oxidation according to claim 1, characterized in that, In step (1), the oxide carrier has a size of 1 nm-100 um and a cubic, octahedral, spherical, or irregular flaky morphology.

4. The method of producing a Pt-based catalyst having a (1x2)-(110) surface structure for catalyzing CO oxidation according to claim 1, characterized in that, In step (1), the platinum source is platinum acetylacetone or platinum nanocubes, the grinding time is 5-60 min, and the size of the Pt nanoparticles is 1 nm-1000 nm.

5. A Pt-based catalyst having a (1 x 2)-(110) surface structure for catalyzing CO oxidation, characterized in that, The Pt-based catalyst is prepared by the method according to any one of claims 1-4 and is used for catalyzing CO oxidation at a temperature in the range of 378 K-1073 K.

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