Optimized construction method for oxygen reduction reaction of porous carbon carrier catalytic layer, storage medium, program product and computer system

Abstract

The invention discloses an optimized construction method for oxygen reduction reaction of a porous carbon carrier catalytic layer, a storage medium, a program product and a computer system, which are applied to the technical field of proton exchange membrane fuel cells, and the method comprises the following steps: S1, constructing a porous carbon carrier comprising a plurality of porous carbon particles; s2, continuing to construct platinum Pt particles in the porous carbon carrier, namely loading a platinum catalyst on the surface of the porous carbon carrier; s3, continuing to construct an ionomer in the secondary pores of the porous carbon carrier; s4, continuously constructing a water film in the primary pores of the porous carbon carrier; and S5, continuing to construct the ionomer in the primary pores of the porous carbon carrier, and finally obtaining the porous carbon carrier catalyst layer. The specific influence of the size and number of primary pores in the porous carbon carrier of the catalytic layer CL of the proton exchange membrane fuel cell PEMFC on the mass diffusion and ORR (oxygen reduction reaction) performance of Pt nanoparticles can be fully revealed.

Description

Technical Field

[0001] The present invention relates to the field of fuel cell technology, specifically to the field of proton exchange membrane fuel cell technology, and in particular to an optimized construction method for oxygen reduction reaction of a porous carbon carrier catalytic layer, a computer readable storage medium, a computer program product containing instructions, and a computer system. Background Art

[0002] Polymer electrolyte membrane (PEM, i.e. proton exchange membrane) fuel cells (PEMFC) have the advantages of high power density, high energy conversion efficiency, environmental friendliness, and broad application prospects. Pt (platinum) catalyst plays a key role in determining the electrochemical reaction within the fuel cell. Pt catalyst accounts for about 42% of the total cost of PEM fuel cell vehicles. Although several new catalysts have been developed, the precious metal Pt remains an important catalyst in PEM fuel cells. In order to achieve cost-effectiveness and large-scale production lines for fuel cell vehicles, the Pt loading should be reduced to less than 0.1 mg Pt cm -2 However, for conventional membrane electrode assemblies (MEAs), current Pt consumption is typically 0.2–0.5 mg cm- 2 Therefore, improving the mass activity of Pt and reducing the amount of Pt loaded are necessary conditions for the commercialization of PEM fuel cells.

[0003] Membrane electrode assembly (MEA) is the core component of proton exchange membrane fuel cells, which consists of three parts: proton exchange membrane (PEM), catalyst layer (CL) and gas diffusion layer (GDL).

[0004] The catalytic layer (CL) consists of carbon black particles (i.e., carbon support), Pt nanoparticles, ionomers, and pores. The porous carbon support has a large number of internal micropores, which allows the Pt nanoparticles to be better dispersed. The Pt nanoparticles tend to be loaded on the internal mesoporous surface of the porous carbon support (73% internal, 23% external), and the Pt particles tend to fall into the internal mesopores with higher pore surface area. When the porous carbon support is covered with a water film, the Pt particles on the internal mesoporous surface act as Pt active sites. This is because both ionomers and condensed water can act as proton conduction paths. In addition, the Pt particles located in the mesopores are protected from the toxic effects of the sulfonate groups in the perfluorosulfonic acid (PFSA) ionomer, thereby increasing its kinetic activity.

[0005] However, there is currently no technology that can fully reveal the specific effects of the size and number of primary pores in the porous carbon support of the catalyst layer CL of the proton exchange membrane fuel cell PEMFC on the mass diffusion of Pt nanoparticles and ORR (i.e. oxygen reduction reaction) performance.

[0006] It should be noted that porous carbon carriers are microparticles with porous properties. The micropores of the microparticles themselves are called primary pores, which are the basic structural characteristics of the carrier. At present, due to the limitation of nanoscale, it is not practical to use advanced equipment to observe the internal transport process of the catalytic layer CL in situ, and its structure and variables are difficult to control accurately.

[0007] Therefore, there is an urgent need to develop a technology that can solve the above technical problems. Summary of the invention

[0008] The purpose of the present invention is to provide an optimized construction method for oxygen reduction reaction of a porous carbon carrier catalytic layer, a computer readable storage medium, a computer program product containing instructions, and a computer system in view of the technical defects of the prior art.

[0009] To this end, the present invention provides a method for optimizing the construction of a porous carbon support catalytic layer oxygen reduction reaction, which is applied to a proton exchange membrane fuel cell. The method comprises the following steps:

[0010] Step S1, constructing a porous carbon support including a plurality of porous carbon particles;

[0011] Step S2, continuing to construct platinum Pt particles in the porous carbon support, that is, loading the platinum catalyst on the surface of the porous carbon support;

[0012] Step S3, continuing to construct ionomers in the secondary pores of the porous carbon support;

[0013] Step S4, continuing to construct a water film in the primary pores of the porous carbon support;

[0014] Step S5, continuing to construct ionomers in the primary pores of the porous carbon support, and finally obtaining a porous carbon support catalytic layer;

[0015] The porous carbon carrier catalytic layer is used as a catalytic layer of a membrane electrode MEA of a proton exchange membrane fuel cell.

[0016] In addition, the present invention provides a computer-readable storage medium, including a program or instruction, which, when executed on a computer, implements the above-mentioned method for optimizing the construction of the porous carbon support catalytic layer oxygen reduction reaction.

[0017] In addition, the present invention provides a computer program product comprising instructions, characterized in that when the computer program product is run on a computer, the computer is enabled to execute the above-mentioned method for optimizing the construction of the oxygen reduction reaction of the porous carbon support catalytic layer.

[0018] In addition, the present invention provides a computer system, including a memory, and one or more processors communicatively connected to the memory;

[0019] The memory stores instructions that can be executed by the one or more processors, and the instructions are executed by the one or more processors to enable the one or more processors to implement the optimized construction method for the oxygen reduction reaction of the porous carbon support catalytic layer as described above.

[0020] It can be seen from the technical solution provided by the present invention that, compared with the prior art, the present invention provides an optimized construction method for the oxygen reduction reaction of a porous carbon carrier catalyst layer, a computer-readable storage medium, a computer program product comprising instructions, and a computer system. The present invention is scientifically designed and can fully reveal the specific effects of the primary pore size and number in the porous carbon carrier of the catalyst layer CL of the proton exchange membrane fuel cell PEMFC on the mass diffusion of Pt nanoparticles and the ORR (i.e., oxygen reduction reaction) performance, and has great practical significance.

[0021] It should be noted that, in view of the pore scale simulation, the multi-scale transport phenomenon and electrochemical reaction in the catalyst layer CL of the proton exchange membrane fuel cell (PEMFC) can be studied. For this purpose, the present invention provides an optimization construction method for the oxygen reduction reaction in the catalyst layer of a porous carbon carrier. The method is a pore scale simulation method for the oxygen reduction reaction in the primary pore of the catalyst layer of a porous carbon carrier, which can provide guidance for the coordinated optimization design of the structural parameters of the porous carbon carrier CL. By applying the present invention, it is helpful to reveal the multi-scale transport phenomenon and electrochemical reaction in the catalyst layer CL of the fuel cell in detail.

[0022] Compared with the prior art, the present invention can simulate the reaction and transport process of oxygen in the porous carbon support catalytic layer, study the influence of the primary pore size and number on the oxygen reduction reaction in the porous carbon catalytic layer, and consider the Pt poisoning effect of the ionomer.

[0023] Compared with the prior art, the present invention reconstructs the two-dimensional structure of the porous carbon support catalyst layer through a random algorithm. The LB method and the single relaxation model are used to comprehensively study the effects of the porous structure of the porous carbon support catalyst layer, such as the size and number of primary pores, on mass diffusion and ORR activity, taking into account the poisoning effect of the intrusion of ionomers on Pt. The present invention establishes the constitutive relationship between the characteristic parameters of the porous carbon structure and the electrochemical reaction, and provides guidance for the optimal design of the characteristic parameters of the porous carbon support catalyst layer structure to improve mass transfer and ORR rate, and ultimately improve the overall performance of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A flow chart of an optimized construction method for oxygen reduction reaction of a porous carbon support catalytic layer provided by the present invention;

[0025] Figure 2 A structural diagram of the solid carbon phase (i.e., multiple solid carbon particles) of the porous carbon carrier catalytic layer structure constructed by the present invention;

[0026] Figure 3 A structural diagram of a porous carbon phase (i.e., a porous carbon carrier including a plurality of porous carbon particles) of a porous carbon carrier catalytic layer structure constructed by the present invention;

[0027] Figure 4 The structure diagram of the porous carbon phase + platinum phase of the porous carbon support catalytic layer structure constructed by the present invention, that is, the structure diagram when the platinum catalyst is loaded on the surface of the porous carbon support;

[0028] Figure 5 The structure diagram of the porous carbon support catalytic layer structure constructed by the present invention is a porous carbon phase + platinum phase + secondary pore ionomer phase, that is, a structure diagram in which a platinum catalyst is loaded on the surface of the porous carbon support and an ionomer is loaded in the secondary pores;

[0029] Figure 6 The structure diagram of the porous carbon carrier catalytic layer structure constructed by the present invention is a porous carbon phase + platinum phase + secondary pore ionomer phase + water, that is, a structure diagram in which a platinum catalyst is loaded on the surface of the porous carbon carrier, an ionomer is loaded in the secondary pores, and a water film is loaded in the primary pores;

[0030] Figure 7 The structure diagram of the porous carbon support catalyst layer structure constructed by the present invention is a porous carbon phase + platinum phase + secondary pore ionomer phase + water + primary pore ionomer phase, that is, a schematic diagram of a structure in which a platinum catalyst is loaded on the surface of a porous carbon support, ionomer is loaded in the secondary pores, a water film is loaded in the primary pores, and ionomer is loaded in the primary pores (i.e., a porous carbon support catalyst layer of a proton exchange membrane fuel cell); wherein the number of pores is 5, and the pore diameter of the primary pore is 8 nm;

[0031] Figure 8A schematic diagram of the enlarged structure of a porous carbon particle in the porous carbon carrier of the porous carbon carrier catalytic layer constructed by the present invention;

[0032] Fig. 9 It is a structural diagram of a porous carbon support catalyst layer of a proton exchange membrane fuel cell with 5 primary pores and a primary pore diameter of 4 nm;

[0033] Fig.10 It is a structural diagram of a porous carbon support catalyst layer of a proton exchange membrane fuel cell with 5 primary pores and a primary pore diameter of 6 nm;

[0034] Fig.11 It is a structural diagram of a porous carbon support catalyst layer of a proton exchange membrane fuel cell with 5 primary pores and a primary pore diameter of 10 nm;

[0035] Fig.12 It is a structural diagram of a porous carbon support catalyst layer of a proton exchange membrane fuel cell with 5 primary pores and a primary pore diameter of 12 nm;

[0036] Fig.13 It is a structural diagram of a porous carbon support catalyst layer of a proton exchange membrane fuel cell with 4 primary pores and a primary pore diameter of 6 nm;

[0037] Fig.14 It is a structural diagram of a porous carbon support catalyst layer of a proton exchange membrane fuel cell with 6 primary pores and a primary pore diameter of 6 nm;

[0038] Fig.15 It is a structural diagram of a porous carbon support catalyst layer of a proton exchange membrane fuel cell with 7 primary pores and a primary pore diameter of 6 nm;

[0039] Fig.16 This is a structural diagram of a porous carbon support catalyst layer of a proton exchange membrane fuel cell with 8 primary pores and a primary pore diameter of 6 nm. DETAILED DESCRIPTION

[0040] The terms "first" and "second" in the specification and drawings of the present application are used to distinguish different objects, or to distinguish different treatments of the same object, rather than to describe a specific order of objects. In addition, the terms "including" and "having" and any variations thereof mentioned in the description of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include other steps or units that are not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0041] It should be noted that, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0042] In the embodiments of the present application, "A and / or B" means A and B, or A or B. "A, and / or B, and / or C" means any one of A, B, and C, or any two of A, B, and C, or A, B, and C. In the embodiments of the present application, "A, B, or C" means any one of A, B, and C.

[0043] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] Embodiment 1

[0045] See also Figures 1 to 16 The present invention provides a method for optimizing the construction of a porous carbon carrier catalyst layer oxygen reduction reaction, which is applied to a proton exchange membrane fuel cell. It is a method for optimizing the construction of a porous carbon carrier catalyst layer oxygen reduction reaction in a proton exchange membrane fuel cell, and it is also a simulation method for the oxygen reduction reaction in a porous carbon carrier catalyst layer in a proton exchange membrane fuel cell. The method comprises the following steps:

[0046] Step S1, constructing a porous carbon support including a plurality of porous carbon particles;

[0047] In the present invention, in specific implementation, the step S1 specifically includes the following steps:

[0048] Step S11, constructing and generating the first solid carbon particle: pre-defining a growth region of the solid carbon particle, and randomly generating coordinates in the growth region as the original growth point of the first solid carbon particle;

[0049] Next, the required radius r of the solid carbon particle is predetermined c , then, the original growth point of the first solid carbon particle is enlarged and expanded to obtain the desired diameter r c The first solid carbon particle;

[0050] In step S11, in practice, the required radius r of the solid carbon particle is c It is pre-set, for example, it can be 25nm.

[0051] In step S11, in terms of specific implementation, the present invention pre-defines the growth area of ​​solid carbon particles in a two-dimensional space. In the two-dimensional space (the space composed of the two dimensions of lateral length and vertical height), the pre-defined growth area of ​​solid carbon particles can be an area with a lateral length of 600*vertical height of 300.

[0052] Step S12, calculating the carbon area ratio of the first solid carbon particle to ensure that it is less than or equal to the pre-required (i.e., pre-set) carbon area ratio ε c ;

[0053] It should be noted that, at present, the solid carbon particles have no primary pores formed thereon, and the shape of the solid carbon particles in the growth region is a solid circle.

[0054] In step S13, in specific implementation, the carbon area ratio is the ratio of the carbon area (i.e., the plane area of ​​the solid carbon particles) to the total area of ​​the growth region;

[0055] The carbon area ratio of the first solid carbon particle is equal to the area of ​​the first solid carbon particle (i.e., the plane area of ​​the solid carbon particle, which is the radius r c The percentage (ratio) of the circular plane) to the total area of ​​the growth region of the solid carbon particle, the area of ​​the growth region of the solid carbon particle is preset, for example, the growth region of the solid carbon particle can be a rectangular region, and its area is the area of ​​the rectangle.

[0056] It should be noted that the carbon area ratio of the plurality of solid carbon particles is equal to the percentage of the sum of the areas of the plurality of solid carbon particles to the growth region area of ​​the solid carbon particles.

[0057] Step S13, in the growth area of ​​the solid carbon particles, continue to perform at least one solid carbon particle construction and generation operation, each time only one solid carbon particle is constructed and generated, and at least one solid carbon particle is constructed and generated until the carbon area ratio reaches the pre-required carbon area ratio ε c Stop the build when

[0058] For example, Figure 2 As shown, the required carbon area ratio ε c is 16%, and the structures of the generated multiple solid carbon particles are as follows Figure 2 As shown in the figure, there is a certain gap between any two adjacent solid carbon particles, which serves as a secondary hole. Figure 2 In the figure, the carbon distribution area is black.

[0059] Step S14, using the center of the growth area of ​​the solid carbon particles predefined in step S11 as the rotation center of the primary hole, constructing and generating multiple primary holes, and the primary holes are assumed to be rectangular and distributed along the radial direction, and their depth is r c， The radius is r p ;

[0060] In step S14, in specific implementation, the process of constructing multiple primary holes in the center of the growth area includes the following three steps:

[0061] Step S141, taking the center of the growth area as the rotation point, generating a depth r c , radius r p The initial rectangle of

[0062] In step S141, in specific implementation, the radius r p That is the size of the primary hole, which is assumed to be 4nm, 6nm, 8nm, 12nm or 14nm.

[0063] Step S142, rotating the initial rectangle clockwise by a preset angle (e.g., 72°) to generate a next rectangle;

[0064] Step S143, repeating step S142, when reaching the preset, required number of primary holes (for example, 5, of course, it can also be 4, 6, 7, 8 and other values), completing the operation of generating the primary hole in the center of the growth area.

[0065] Step S15, after the primary hole in the center of the growth region described in step S14 is generated, assigning the central coordinates of the primary hole in the center of the growth region to the central coordinates of each solid carbon particle to generate a porous carbon carrier including a plurality of porous carbon particles;

[0066] The structure of the porous carbon carrier including a plurality of porous carbon particles is as follows: Figure 3 As shown. Figure 3 In the figure, the carbon distribution area is black.

[0067] Step S2, continuing to construct platinum Pt particles in the porous carbon support, that is, loading the platinum catalyst on the surface of the porous carbon support;

[0068] In the present invention, in specific implementation, the step S2 includes the following steps:

[0069] Step S21, constructing and generating platinum Pt particles in each porous carbon particle included in the porous carbon carrier, thereby constructing platinum Pt particles in the porous carbon carrier, that is, loading platinum catalyst on the surface of the porous carbon carrier, such as Figure 4 shown in Figure 4 In the porous carbon particles shown, the color of the carbon distribution area is black; the color of the platinum Pt particle distribution area is red.

[0070] Specifically, in step S21, platinum Pt particles are constructed in each porous carbon particle, which specifically includes the following operations:

[0071] Step S211, pre-defining random numbers x1 and x2 in the range of 0 to 1, and initial distribution probabilities p0 and p1 of platinum Pt lattice growth in the primary pores and secondary pores of the porous carbon particles;

[0072] It should be noted that in the present invention, it is assumed that at a pore size of 4 nm, the Pt particles in the primary pores of the porous carbon particles account for 70% of the total Pt particles on the porous carbon particles, and as the pore size increases, the ratio of the Pt particles in the primary pores to the total Pt particles on the porous carbon particles increases by 1.05 times. Define random numbers x1 and x2 in the range of 0 to 1, as well as the initial distribution probabilities p0 and p1 of the growth of the Pt lattice in the primary pores and the secondary pores (the values ​​of p0 and p1 are adjusted according to the size of the area proportion of the platinum actually generated until the desired area proportion of platinum is generated, and the area proportion of platinum required by the present invention is 1.39%).

[0073] Step S212, Pt growth seeds are randomly distributed on the carbon surface of the porous carbon particle, and all lattices at the carbon surface interface are assigned random numbers; when the random number x1 / x2 of the lattice is not greater than p0 / p1, the lattice is a Pt growth point, and then the original growth point generated is expanded according to the required Pt particle diameter, thereby obtaining Pt particles of a predetermined diameter on the surface of the porous carbon particle;

[0074] In step S212, in a specific implementation, the diameter of the Pt particles is pre-given, and the diameter range is 2-3 nm.

[0075] It should be noted that, if the expanded Pt particles overlap with the carbon particles, the carbon particles are preferentially generated.

[0076] Step S213, repeating step S212 to generate multiple Pt particles on the surface of the porous carbon particles until the area ratio of the Pt particles in the primary pores and secondary pores of the porous carbon particles reaches a preset primary pore area ratio ε Pt1 and the preset secondary hole area ratio ε Pt2 , and the total area content reaches ε Pt (eg, 1.39%), step S212 is stopped, and finally a structure in which a platinum catalyst is loaded on the surface of a porous carbon carrier is obtained.

[0077] It should be noted that, in the present invention, the exposure of Pt particles on the surface of the carbon carrier is ignored. Therefore, for the porous carbon carrier (i.e., porous carbon carrier) of the catalyst layer CL in the proton exchange membrane fuel cell, in the primary pores of each porous carbon particle included in the porous carbon carrier, the Pt particles are covered by the thin water film in the catalyst layer CL; in the secondary pores of the porous carbon carrier, all lattice points of the Pt particles are sandwiched between the carbon phase and the ionomer in the catalyst layer CL.

[0078] Step S3, continuing to construct ionomers in the secondary pores of the porous carbon support;

[0079] In the present invention, in specific implementation, the step S3 includes the following steps:

[0080] Step S31, using a quadruple structure generating set (QSGS) algorithm, further adding an ionomer to the structural domain to obtain a structure in which a platinum catalyst is loaded on the surface of the porous carbon support and an ionomer is loaded in the secondary pores;

[0081] In specific implementation, step S31 includes the following operations:

[0082] Step S311, multiple parameters are predefined, including a random number x3 in the range of 0 to 1, the initial distribution probability p2 of the ionomer seeds in the secondary pores, and the growth probability p2 of the ionomer seeds in each direction. α (α represents the growth direction, and the probability can be different for different directions);

[0083] Step S312, randomly distributing ionomer seeds on the carbon-secondary pore and Pt-secondary pore interfaces, and all lattices at the interfaces are assigned random numbers;

[0084] When the random number x3 of the lattice is not greater than p2, the lattice is an ionomer seed;

[0085] Step S313, each ionomer seed is separated into two groups according to the determined probability p. α Grow towards adjacent grid points, that is, reallocate a random number x to all grid points adjacent to the α direction of the seed;

[0086] If the random number x is less than p α , then the grid points become the growth stages, and the shape of the ionomer skeleton is determined by setting different probabilities p in each direction. α to control;

[0087] It should be noted that, in the present invention, since ionomers are usually irregular and disordered, the probabilities of all directions are the same.

[0088] Step S314, continue to generate multiple new ionomer seeds and define their growth until the ionomer content in the secondary pores of the porous carbon support reaches εion2 , and finally a structure in which the platinum catalyst is loaded on the surface of the porous carbon support and the ionomer is loaded in the secondary pores is obtained.

[0089] In step S314, in specific implementation, the total ionomer content on the porous carbon support is ε ion (ε ion =15%), then the ionomer content in the secondary pores of the porous carbon support is equal to the total ionomer content on the porous carbon support minus the content in the primary pores of the porous carbon support (ε ion1 )

[0090] When the primary pore diameter is 4nm or 6nm, ε ion1 When the primary pore diameter is greater than 6 nm, the ratio of the ionomer intrusion content in the primary pore to the area of ​​the primary pore is assumed to be 10%, 20% and 30%. Through step S3, the structure of the porous carbon phase, platinum phase and secondary pore ionomer phase is as follows: Figure 5 As shown, the structure of the porous carbon support with platinum catalyst loaded on the surface and ionomer loaded in the secondary pores is as shown in Figure 5 shown.

[0091] exist Figure 5 In the figure, the distribution area of ​​the ionomer is green and is distributed in the secondary pores (i.e., the surface of the porous carbon particles); the distribution area of ​​the carbon is black; and the distribution area of ​​the platinum Pt particles is red.

[0092] Step S4, continuing to construct a water film in the primary pores of the porous carbon support;

[0093] In the present invention, in specific implementation, the step S4 includes the following steps:

[0094] Step S41, for the porous carbon carrier obtained in step S3, continue to add water to the primary pores of the porous carbon carrier. At this time, first, all the lattices at the platinum surface interface in the primary pores are assigned as growth points of water, and then, according to the required thickness of the water film, the original growth points generated are expanded (the thickness of the water film of the present invention is 1 nm), thereby obtaining a structure in which the platinum catalyst is loaded on the surface of the porous carbon carrier, the ionomer is loaded in the secondary pores, and the water film is loaded in the primary pores.

[0095] In step S41, if the expanded thin water film overlaps with the platinum particles, the platinum particles are generated first. Figure 6 shown.

[0096] It should be noted that, through step S4, the structure of the porous carbon phase, the platinum phase, the secondary pore ionomer phase and the water film is as follows: Figure 6As shown, the structure in which the platinum catalyst is loaded on the surface of the porous carbon support, the ionomer is loaded in the secondary pores, and the water film is loaded in the primary pores is as shown in Figure 6 shown.

[0097] exist Figure 6 In the figure, the distribution area of ​​the ionomer is green and is distributed in the secondary pores (i.e., the surface of the porous carbon particles); the distribution area of ​​carbon is black; the distribution area of ​​water is blue; and the distribution area of ​​platinum Pt particles is red.

[0098] Step S5, continuing to construct ionomers in the primary pores of the porous carbon support, and finally obtaining a porous carbon support catalytic layer;

[0099] The porous carbon carrier catalytic layer is used as a catalytic layer of a membrane electrode MEA of a proton exchange membrane fuel cell.

[0100] In the present invention, in specific implementation, the step S5 includes the following steps:

[0101] The step S51, according to the preset ratio of the ionomer invading the primary pores, adds the ionomer into the primary pores, obtains a structure in which the platinum catalyst is loaded on the surface of the porous carbon carrier, the ionomer is loaded in the secondary pores, the water film is loaded in the primary pores, and the ionomer is loaded in the primary pores, that is, a porous carbon carrier catalytic layer is obtained;

[0102] In specific implementation, the step S51 specifically includes the following steps:

[0103] Step S511, predefine a random number x4 in the range of 0 to 1, and an initial distribution probability p3 of ionomer lattice growth in a primary hole (the value of p3 is adjusted according to the size of the area ratio of the ionomer in the primary hole actually generated, until an ionomer with a required area ratio is generated);

[0104] Step S512, randomly distributing ionomer growth seeds on the carbon surface of the primary pores, and all lattices at the carbon surface interface are assigned random numbers;

[0105] When the random number x4 of the lattice is not greater than p3, the lattice is the growth point of the ionomer;

[0106] Step S513, expanding the generated original growth points to obtain ionomers with a predetermined area ratio, and finally obtaining a structure in which a platinum catalyst is loaded on the surface of the porous carbon support, ionomers are loaded in the secondary pores, a water film is loaded in the primary pores, and ionomers are loaded in the primary pores;

[0107] It should be noted that, through step S5, the structure of the porous carbon phase, the platinum phase, the secondary pore ionomer phase, the water film and the primary pore ionomer phase is as follows: Figure 7As shown, the structure of loading platinum catalyst on the surface of porous carbon support, loading ionomer in secondary pores, loading water film in primary pores and loading ionomer in primary pores is as shown in FIG. Figure 7 As shown. Figure 7 The porous carbon carrier shown has an enlarged structure of a porous carbon particle as shown in Figure 8 shown.

[0108] exist Figure 7 , Figure 8 In the porous carbon particles shown, the distribution area of ​​the ionomer is green, distributed in the primary pores and secondary pores (i.e., the surface of the porous carbon particles); the distribution area of ​​carbon is black; the distribution area of ​​water is blue; and the distribution area of ​​platinum Pt particles is red.

[0109] In the present invention, the structure in which platinum catalyst is loaded on the surface of the porous carbon carrier, ionomer is loaded in the secondary pores, water film is loaded in the primary pores and ionomer is loaded in the primary pores is the porous carbon carrier catalytic layer.

[0110] In the present invention, by pre-determining the number and pore diameter of the primary pores, a porous carbon support catalyst layer with different structures can be obtained. Figures 9 to 16 As shown, Fig. 9 It is a structural diagram of a porous carbon support catalyst layer with 5 primary pores and a primary pore diameter of 4 nm; Fig.10 It is a structural diagram of a porous carbon support catalyst layer with 5 primary pores and a primary pore diameter of 6 nm; Fig.11 It is a structural diagram of a porous carbon support catalyst layer with 5 primary pores and a primary pore diameter of 10 nm; Fig.12 It is a structural diagram of a porous carbon support catalyst layer with 5 primary pores and a primary pore diameter of 12 nm; Fig.13 It is a structural diagram of a porous carbon support catalyst layer with 4 primary pores and a primary pore diameter of 6 nm; Fig.14 It is a structural diagram of a porous carbon support catalyst layer with 6 primary pores and a primary pore diameter of 6 nm; Fig.15 It is a structural diagram of a porous carbon support catalyst layer with 7 primary pores and a primary pore diameter of 6 nm;

[0111] Fig.16 The first is a structural diagram of a porous carbon support catalytic layer with 8 pores and a pore diameter of 6 nm.

[0112] In the present invention, in specific implementation, for the above-mentioned method for optimizing the construction of the oxygen reduction reaction of the porous carbon support catalyst layer provided by the present invention (i.e., the simulation method of the oxygen reduction reaction of the porous carbon support catalyst layer of the proton exchange membrane fuel cell), for the porous carbon support catalyst layer obtained by the above-mentioned steps S1 to S5, when the platinum Pt particles of the primary pores of the porous carbon support catalyst layer are all covered by a layer of water film, in order to simulate the oxygen reduction reaction of oxygen in the porous carbon support catalyst layer (i.e., the reaction transport process), at least one of the following operations (i.e., any one or more of the first operation, the second operation, and the third operation) is included:

[0113] First operation: if the oxygen reduction reaction (i.e., reaction transport process) of oxygen in the porous carbon support catalyst layer needs to be simulated, it is the diffusion process of oxygen in the pores in the porous carbon support catalyst layer, and the diffusion process follows the following formula (1):

[0114]

[0115] Among them, D p and C g , respectively represent the oxygen diffusion rate and concentration in the pore, D p =4×10 -6 m 2 s -1 .

[0116] The initial concentration of oxygen in the present invention is 1 mol m -3 , oxygen diffuses from the outer edge of the catalyst layer to the inside of the catalyst layer;

[0117] Second operation: If the oxygen reduction reaction (i.e., reaction transport process) of oxygen in the porous carbon support catalyst layer needs to be simulated, it is the diffusion process of oxygen in water or ionomer in the porous carbon support catalyst layer. The diffusion process in water or ionomer follows the following formulas (2) and (3), respectively:

[0118]

[0119] Among them, D W and D I , are the diffusivities of oxygen in water and ionomer, respectively;

[0120] D W =6.7×10 -9 m 2 s -1 ;D I =8.7×10 -10 m 2 s -1 ;

[0121] C W and C I, are the oxygen concentrations in the ionomer and water, respectively.

[0122] The third operation: if the oxygen reduction reaction (i.e., the reaction transport process) of oxygen in the porous carbon support catalytic layer needs to be simulated, it is the process of electrochemical reaction of oxygen on the surface of active Pt nanoparticles, which follows the following chemical reaction formula (4):

[0123]

[0124] Where F represents the Faraday constant, for example, F = 96485.3383 C mol -1 ;

[0125] C ref and are the reference and local oxygen concentrations, respectively, such as C ref =3.39 mol m - 3;

[0126] I ref Indicates the reference current density, such as I ref =1A m -2 ;

[0127] α c represents the transfer coefficient, such as α c =0.5;

[0128] η represents the overpotential, k represents the reaction rate constant;

[0129] T represents temperature, for example, T = 313K;

[0130] R represents the gas constant, for example, R = 8.314 J (mol*K) -1 ;

[0131] It should be noted that, for the present invention, the Pt-water interface reaction rate constant is selected as 80 m s -1 , the reaction rate constant at Pt-ionomer is 20 m s -1 .

[0132] Embodiment 2

[0133] In an embodiment of the present invention, a computer-readable storage medium is also provided, comprising a program or instruction. When the program or instruction is executed on a computer, the optimized construction method of the porous carbon support catalytic layer oxygen reduction reaction as described in Example 1 is implemented.

[0134] Embodiment 3

[0135] In an embodiment of the present invention, a computer program product comprising instructions is also provided. When the computer program product is run on a computer, the computer executes the method for optimizing the construction of the oxygen reduction reaction of the porous carbon support catalytic layer as described in Example 1.

[0136] Embodiment 4

[0137] In an embodiment of the present invention, a computer system is further provided, comprising a memory, and one or more processors communicatively connected to the memory;

[0138] The memory stores instructions that can be executed by the one or more processors, and the instructions are executed by the one or more processors to enable the one or more processors to implement the optimized construction method for the oxygen reduction reaction of the porous carbon support catalytic layer as described in Example 1.

[0139] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for optimizing the construction of a porous carbon support catalyst layer for oxygen reduction reaction, characterized in that: Applied to a proton exchange membrane fuel cell, the method comprises the following steps: Step S1, constructing a porous carbon support including a plurality of porous carbon particles; Step S2, continuing to construct platinum Pt particles in the porous carbon support, that is, loading the platinum catalyst on the surface of the porous carbon support; Step S3, continuing to construct ionomers in the secondary pores of the porous carbon support; Step S4, continuing to construct a water film in the primary pores of the porous carbon support; Step S5, continuing to construct ionomers in the primary pores of the porous carbon support, and finally obtaining a porous carbon support catalytic layer; The porous carbon carrier catalytic layer is used as a catalytic layer of a membrane electrode MEA of a proton exchange membrane fuel cell.

2. The method for optimizing the construction of the porous carbon support catalyst layer oxygen reduction reaction according to claim 1, characterized in that: The step S1 specifically comprises the following steps: Step S11, constructing and generating the first solid carbon particle: pre-defining a growth region of the solid carbon particle, and randomly generating coordinates in the growth region as the original growth point of the first solid carbon particle; Next, the required radius r of the solid carbon particle is predetermined c , then, the original growth point of the first solid carbon particle is enlarged and expanded to obtain the desired diameter r c The first solid carbon particle; Step S12, calculating the carbon area ratio of the first solid carbon particle to ensure that it is less than or equal to the pre-required carbon area ratio ε c ; Step S13, in the growth area of ​​the solid carbon particles, continue to perform at least one solid carbon particle construction and generation operation, each time only one solid carbon particle is constructed and generated, and at least one solid carbon particle is constructed and generated until the carbon area ratio reaches the pre-required carbon area ratio ε c Stop the build when Step S14, using the center of the growth area of ​​the solid carbon particles predefined in step S11 as the rotation center of the primary hole, constructing and generating multiple primary holes, and the primary holes are assumed to be rectangular and distributed along the radial direction, and their depth is r c , with a radius of r p ; Step S15, after the primary hole in the center of the growth region described in step S14 is generated, assigning the central coordinates of the primary hole in the center of the growth region to the central coordinates of each solid carbon particle to generate a porous carbon carrier including a plurality of porous carbon particles; and / or, The step S2 comprises the following steps: Step S21, constructing and generating platinum (Pt) particles in each porous carbon particle included in the porous carbon carrier, thereby constructing platinum (Pt) particles in the porous carbon carrier, that is, loading platinum catalyst on the surface of the porous carbon carrier; and / or, The step S3 comprises the following steps: Step S31, using a quadruple structure generation set QSGS algorithm, further adding an ionomer to the structural domain to obtain a structure in which a platinum catalyst is loaded on the surface of the porous carbon support and an ionomer is loaded in the secondary pores; and / or, The step S4 comprises the following steps: Step S41, for the porous carbon support obtained in step S3, continue to add water into the primary pores of the porous carbon support, at this time, firstly, all the lattices at the platinum surface interface in the primary pores are allocated as water growth points, and then, according to the required thickness of the water film, the generated original growth points are expanded, thereby obtaining a structure in which the platinum catalyst is loaded on the surface of the porous carbon support, the ionomer is loaded in the secondary pores, and the water film is loaded in the primary pores; and / or, The step S5 comprises the following steps: In step S51, according to a preset ratio of ionomer invading the primary pores, ionomer is added into the primary pores to obtain a structure in which a platinum catalyst is loaded on the surface of the porous carbon carrier, ionomer is loaded in the secondary pores, a water film is loaded in the primary pores, and ionomer is loaded in the primary pores, that is, a porous carbon carrier catalytic layer is obtained.

3. The method for optimizing the construction of the porous carbon support catalyst layer oxygen reduction reaction according to claim 2, characterized in that: In step S14, the process of constructing multiple primary holes in the center of the growth area includes the following three steps: Step S141, taking the center of the growth area as the rotation point, generating a depth r c , radius r p The initial rectangle of Step S142, rotating the initial rectangle clockwise by a preset angle to generate a next rectangle; Step S143, repeating step S142, when the preset and required number of primary holes is reached, the operation of generating the primary hole in the center of the growth area is completed.

4. The method for optimizing the construction of the porous carbon support catalyst layer oxygen reduction reaction according to claim 2, characterized in that: In step S21, platinum Pt particles are constructed in each porous carbon particle, specifically including the following operations: Step S211, pre-defining random numbers x1 and x2 in the range of 0 to 1, and initial distribution probabilities p0 and p1 of platinum Pt lattice growth in the primary pores and secondary pores of the porous carbon particles; Step S212, Pt growth seeds are randomly distributed on the carbon surface of the porous carbon particle, and all lattices at the carbon surface interface are assigned random numbers; when the random number x1 / x2 of the lattice is not greater than p0 / p1, the lattice is a Pt growth point, and then the original growth point generated is expanded according to the required Pt particle diameter, thereby obtaining Pt particles of a predetermined diameter on the surface of the porous carbon particle; Step S213, repeating step S212 to generate multiple Pt particles on the surface of the porous carbon particles until the area ratio of the Pt particles in the primary pores and secondary pores of the porous carbon particles reaches a preset primary pore area ratio ε Pt1 and the preset secondary hole area ratio ε Pt2 , and the total area content reaches ε Pt When , step S212 is stopped, and finally a structure in which a platinum catalyst is loaded on the surface of a porous carbon support is obtained.

5. The method for optimizing the construction of the porous carbon support catalyst layer oxygen reduction reaction according to claim 2, characterized in that: Step S31 includes the following operations: Step S311, multiple parameters are predefined, including a random number x3 in the range of 0 to 1, the initial distribution probability p2 of the ionomer seeds in the secondary pores, and the growth probability p2 of the ionomer seeds in each direction. α ; α represents the growth direction; Step S312, randomly distributing ionomer seeds on the carbon-secondary pore and Pt-secondary pore interfaces, and all lattices at the interfaces are assigned random numbers; When the random number x3 of the lattice is not greater than p2, the lattice is an ionomer seed; Step S313, each ionomer seed is separated into two groups according to the determined probability p. α Grow towards adjacent grid points, that is, reallocate a random number x to all grid points adjacent to the α direction of the seed; If the random number x is less than p α , then the grid points become the growth stages, and the shape of the ionomer skeleton is determined by setting different probabilities p in each direction. α to control; Step S314, continue to generate multiple new ionomer seeds and define their growth until the ionomer content in the secondary pores of the porous carbon support reaches ε ion2 , and finally a structure in which the platinum catalyst is loaded on the surface of the porous carbon support and the ionomer is loaded in the secondary pores is obtained.

6. The method for optimizing the construction of the porous carbon support catalyst layer oxygen reduction reaction according to claim 2, characterized in that: The step S51 specifically includes the following steps: Step S511, pre-define a random number x4 in the range of 0 to 1 and an initial distribution probability p3 of ionomer lattice growth in a hole; Step S512, randomly distributing ionomer growth seeds on the carbon surface of the primary pores, and all lattices at the carbon surface interface are assigned random numbers; When the random number x4 of the lattice is not greater than p3, the lattice is the growth point of the ionomer; Step S513, expanding the generated original growth points to obtain ionomers with a predetermined area ratio, and finally obtaining a structure in which a platinum catalyst is loaded on the surface of the porous carbon support, ionomers are loaded in the secondary pores, a water film is loaded in the primary pores, and ionomers are loaded in the primary pores; The structure in which platinum catalyst is loaded on the surface of the porous carbon carrier, ionomer is loaded in the secondary pores, water film is loaded in the primary pores and ionomer is loaded in the primary pores is the porous carbon carrier catalytic layer.

7. The method for optimizing the construction of a porous carbon support catalyst layer for oxygen reduction reaction according to any one of claims 1 to 6, characterized in that: For the porous carbon support catalyst layer obtained in step S5, when the platinum Pt particles in the primary pores of the porous carbon support catalyst layer are all covered by a layer of water film, in order to simulate the oxygen reduction reaction of oxygen in the porous carbon support catalyst layer, at least one of the following operations is included: First operation: If the oxygen reduction reaction of oxygen in the porous carbon support catalyst layer needs to be simulated, it is the diffusion process of oxygen in the pores in the porous carbon support catalyst layer, and the diffusion process follows the following formula (1): ▽(D P ▽(C g ))=0, formula (1); Among them, D p and C g , respectively represent the oxygen diffusion rate and concentration in the pore, D p =4×10 -6 m 2 s -1 ; Second operation: If the oxygen reduction reaction of oxygen in the porous carbon support catalyst layer needs to be simulated, it is the diffusion process of oxygen in water or ionomer in the porous carbon support catalyst layer. The diffusion process in water or ionomer follows the following formulas (2) and (3) respectively: ▽(D W ▽(C W ))=0, formula (2); ▽(D I ▽(C I ))=0, formula (3); Among them, D W and D I , are the diffusivities of oxygen in water and ionomer, respectively; C W and C I , are the oxygen concentrations in the ionomer and water, respectively; The third operation: if the oxygen reduction reaction of oxygen in the porous carbon support catalytic layer needs to be simulated, it is the process of electrochemical reaction of oxygen on the surface of active Pt nanoparticles, which follows the following chemical reaction formula (4): Where, F represents the Faraday constant; C ref and are the reference and local oxygen concentrations, respectively; I ref represents the reference current density; α c represents the transfer coefficient; η represents the overpotential, k represents the reaction rate constant; T represents temperature; R represents the gas constant.

8. A computer-readable storage medium, characterized in that: The method comprises a program or an instruction, and when the program or the instruction is executed on a computer, the method for optimizing the construction of the oxygen reduction reaction of the porous carbon support catalytic layer as claimed in any one of claims 1 to 7 is realized.

9. A computer program product comprising instructions, characterized in that When the computer program product is run on a computer, the computer is enabled to execute the method for optimizing the construction of the oxygen reduction reaction of the porous carbon support catalytic layer according to any one of claims 1 to 7.

10. A computer system, characterized in that: comprising a memory, and one or more processors communicatively connected to the memory; The memory stores instructions that can be executed by the one or more processors, and the instructions are executed by the one or more processors so that the one or more processors implement the optimized construction method for the oxygen reduction reaction of the porous carbon support catalytic layer as described in any one of claims 1 to 7.

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