A controllable design method for porous structures based on computer simulation

Abstract

The present invention provides a method for controllable design of porous structures based on computer simulation, comprising the following steps: (1) constructing a preliminary porous structure based on the type and function of the target structure; (2) establishing a calculation model based on physical processes and chemical reactions; (3) quantitatively characterizing the target performance of the porous structure obtained in step (1), and using the calculation model obtained in step (2) to perform simulation calculations to obtain simulation results; (4) performing targeted adjustment and optimization on the porous structure obtained in step (1) according to the simulation results obtained in step (3) to obtain an optimized porous structure, and performing simulation calculations in step (3) again; (5) when the simulation results obtained in step (3) reach an optimal solution, the porous structure obtained in step (4) is the porous structure with the best target performance, and is saved to guide the subsequent processing and preparation of the porous structure. The method realizes controllable design of the porous structure based on the target performance of the porous structure.

Description

Technical Field

[0001] The invention belongs to the technical field of computer-aided engineering, and relates to a structural design method, in particular to a controllable design method of a porous structure based on computer simulation. Background Art

[0002] The synthesis of porous structures such as molecular sieve catalysts and adsorbents has always been a research hotspot in the field of materials chemistry, and has broad application prospects in many fields such as catalysis, adsorption, separation and sensors. At present, molecular sieve catalysts are mostly synthesized by hydrothermal method, and their specific synthesis method will be optimized according to the purpose of synthesizing molecular sieves.

[0003] The most critical feature of porous molecular sieve catalysts and adsorbents during use is their unique pore structure. At present, most of the pore structures of molecular sieve catalysts obtained by hydrothermal synthesis methods are random pore structures. In recent years, there are also some methods for synthesizing mesoporous molecular sieves with ordered pore structures. For example, CN1693203A discloses a method for preparing and regulating the ordered pore structure of mesoporous molecular sieves, wherein the method uses GEM16-6-16 surfactant as a structure-directing agent and ethylamine as a pH buffer, and synthesizes mesoporous materials with highly ordered different pore structures by changing the ratio of co-solvent ethanol / water, such as two-dimensional hexagonal mesoporous MCM-41, three-dimensional cubic MCM-48, layered structure MCM-50 and hollow sphere structure materials. CN107416858A discloses a MCM-22 molecular sieve with controllable pore structure and a preparation method thereof, which can realize the regulation of micropores, mesopores and total specific surface area.

[0004] For the preparation of porous structures such as molecular sieve catalysts or adsorbents, current research is basically focused on new methods and mechanisms for the synthesis of molecular sieves. Although there are some methods for regulating mesoporous channels, the obtained structures are basically random channel structures, and none of them involve pre-design and regulation of channel connectivity, channel size changes, distribution of functional sites, etc., especially there is no targeted optimization design for the performance of the channels. Therefore, the diffusion process in the channel is affected, and the channel structure (including the distribution of functional sites) cannot be controlled in advance according to the function of the target structure, so as to obtain high-performance, high-efficiency porous structures such as catalysts and adsorbents.

[0005] It can be seen from this that how to provide a controllable design method for porous structures based on computer simulation, starting from the target performance of the porous structure, and controlling the optimization of the pore structure according to the simulation results, so as to achieve the best target performance, and realize that each local pore structure is obtained through controllable design optimization, and avoid uncontrollable random structures, has become an urgent problem that technical personnel in this field need to solve. Summary of the invention

[0006] The object of the present invention is to provide a controllable design method for a porous structure based on computer simulation. The controllable design method for a porous structure starts from the target performance of the porous structure and controllably optimizes the pore structure according to the simulation results, thereby achieving the best target performance and realizing that each local pore structure is obtained through controllable design optimization, thereby avoiding uncontrollable random structures.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for controllable design of a porous structure based on computer simulation, and the method for controllable design of a porous structure comprises the following steps:

[0009] (1) Construct a preliminary porous structure based on the type and function of the target structure;

[0010] (2) Establish computational models based on physical processes and chemical reactions;

[0011] (3) quantitatively characterizing the target performance of the porous structure obtained in step (1), and performing simulation calculations using the calculation model obtained in step (2) to obtain simulation results;

[0012] (4) According to the simulation results obtained in step (3), the porous structure obtained in step (1) is adjusted and optimized to obtain an optimized porous structure, and the simulation calculation of step (3) is performed again;

[0013] (5) When the simulation result obtained in step (3) reaches the optimal solution, the porous structure obtained in step (4) is the porous structure with the best target performance, which is saved to guide the subsequent processing and preparation of the porous structure.

[0014] The method provided by the present invention can realize controllable optimization design of various complex multi-level pore structures, and the obtained porous structure parameters are stable, and it has very strong repeatability in the subsequent porous structure preparation process, and its optimal target performance can be well guaranteed. At the same time, according to the change of actual operating conditions, the pore structure can also be conveniently regulated and designed again, so that it can achieve the optimal target performance under the new operating conditions.

[0015] Preferably, the porous structure in step (1) has a non-functional matrix or is entirely composed of functional components.

[0016] Preferably, the overall shape of the porous structure in step (1) includes any one of a cuboid, a cube, a sphere or an irregular shape.

[0017] Preferably, the characteristic parameters set in the construction process of the porous structure in step (1) include any one or a combination of at least two of porosity, pore size, pore size distribution, pore opening and closing, pore connection topology, content of functional sites, distribution of functional sites or distribution of doping components. Typical but non-limiting combinations include a combination of porosity and pore size, a combination of pore size and pore size distribution, a combination of pore size distribution and pore opening and closing, a combination of pore opening and closing and pore connection topology, a combination of pore connection topology and content of functional sites, a combination of content of functional sites and distribution of functional sites, or a combination of distribution of functional sites and distribution of doping components.

[0018] Preferably, the physical process in step (2) includes any one of diffusion, adsorption or desorption, or a combination of at least two of them. Typical but non-limiting combinations include a combination of diffusion and adsorption, a combination of adsorption and desorption, or a combination of diffusion, adsorption and desorption.

[0019] Preferably, the chemical reaction in step (2) comprises any one of a combination reaction, a decomposition reaction, a replacement reaction, a double decomposition reaction, a substitution reaction, an addition reaction, an elimination reaction, a pericyclic reaction, a rearrangement reaction or a redox reaction, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of a combination of a combination reaction and a decomposition reaction, a combination of a replacement reaction and a double decomposition reaction, a combination of a substitution reaction and an addition reaction, a combination of an elimination reaction and a pericyclic reaction, or a combination of a rearrangement reaction and a redox reaction.

[0020] Preferably, the simulation parameters set in the computational model of step (2) during the establishment process include any one or a combination of at least two of the mass, atomic composition, equivalent diameter of atoms or molecules of each component, reaction temperature, reaction pressure, initial conditions, boundary conditions, chemical reaction path, chemical reaction network, energy transfer or conversion path. Typical but non-limiting combinations include the combination of the mass, atomic composition, equivalent diameter of atoms or molecules of each component, reaction temperature, reaction pressure, initial conditions, boundary conditions and chemical reaction path, the combination of the mass, atomic composition, equivalent diameter of atoms or molecules of each component, reaction temperature, reaction pressure, initial conditions, boundary conditions and chemical reaction network, or the combination of the mass, atomic composition, equivalent diameter of atoms or molecules of each component, reaction temperature, reaction pressure, initial conditions, boundary conditions and energy transfer or conversion path.

[0021] Preferably, the target parameters obtained after quantitative characterization of the target performance in step (3) include any one or a combination of at least two of the reaction performance of each component in the porous structure, diffusion performance, time-space yield of the product, product selectivity, conversion rate of the reactant, adsorption rate or adsorption amount. Typical but non-limiting combinations include a combination of the reaction performance and diffusion performance of each component in the porous structure, a combination of diffusion performance and time-space yield of the product, a combination of time-space yield of the product and product selectivity, a combination of product selectivity and conversion rate of the reactant, a combination of conversion rate of the reactant and adsorption rate, or a combination of adsorption rate and adsorption amount.

[0022] In the present invention, the reaction performance refers to the ability of the porous structure to transform substances at the functional site when there is no mass transfer limitation, which can be characterized by the ratio of the number of effective actions of the reaction components occurring at the functional site per unit time to the total number of actions; the diffusion performance refers to the ability of the porous structure to provide component molecules with diffusion and reach the functional site at the molecular level, which can be characterized by the ratio of the number of molecules acting with the functional site per unit time to the total number of molecules diffused into (or diffused out of) the outer surface of the porous structure; the time-space yield of the product can be characterized by the number of product components diffused from the outer surface of the porous structure per unit volume per unit time; the selectivity of the product can be characterized by the percentage of the number of a certain specified target product obtained after the reaction to the number of a certain specified reactant consumed; the conversion rate of the reactant can be characterized by the percentage or fraction of a certain reactant converted; the adsorption rate can be characterized by the amount of adsorbate adsorbed per unit time.

[0023] In the present invention, the target parameter can be used to characterize the target performance of the entire or local porous structure.

[0024] Preferably, the adjustment optimization in step (4) is based on the principle of diffusion-reaction coupling coordination.

[0025] Preferably, the direction of the adjustment and optimization in step (4) is to achieve any one of maximization, maximization, minimization or minimization of the target performance in step (3).

[0026] In the present invention, in step (5), the porous structure with the best target performance is saved as a data file through a program, and the file format can be specifically set according to the subsequent processing and preparation requirements of the porous structure.

[0027] As a preferred technical solution of the present invention, the controllable design method of porous structure comprises the following steps:

[0028] (1) constructing a preliminary porous structure based on the type and function of the target structure; the porous structure has a non-functional matrix or is entirely functional components, and the overall shape includes any one of a cuboid, a cube, a sphere or an irregular shape; the characteristic parameters set in the porous structure during the construction process include any one of porosity, pore size, pore size distribution, pore opening and closing, topological structure of pore connection, content of functional sites, distribution of functional sites or distribution of doping components, or a combination of at least two of them;

[0029] (2) establishing a computational model based on physical processes and chemical reactions; the physical process includes any one of diffusion, adsorption or desorption or a combination of at least two of them; the chemical reaction includes any one of combination reaction, decomposition reaction, replacement reaction, metathesis reaction, substitution reaction, addition reaction, elimination reaction, pericyclic reaction, rearrangement reaction or redox reaction or a combination of at least two of them; the simulation parameters set in the computational model during the establishment process include any one of the mass of each component, atomic composition, equivalent diameter of atoms or molecules, reaction temperature, reaction pressure, initial conditions, boundary conditions, chemical reaction path, chemical reaction network, energy transfer or conversion path or a combination of at least two of them;

[0030] (3) quantitatively characterizing the target performance of the porous structure obtained in step (1), and performing simulation calculations using the calculation model obtained in step (2) to obtain simulation results; the target parameters obtained after the quantitative characterization of the target performance include any one or a combination of at least two of the reaction performance, diffusion performance, time-space yield of the product, selectivity of the product, conversion rate of the reactant, adsorption rate or adsorption amount of each component in the porous structure;

[0031] (4) Based on the principle of diffusion-reaction coupling coordination, the porous structure obtained in step (1) is adjusted and optimized according to the simulation results obtained in step (3) to obtain an optimized porous structure, and the simulation calculation of step (3) is performed again; the direction of the adjustment and optimization is to achieve any one of maximization, maximization, minimization or minimization of the target performance in step (3);

[0032] (5) When the simulation result obtained in step (3) reaches the optimal solution, the porous structure obtained in step (4) is the porous structure with the best target performance, which is saved to guide the subsequent processing and preparation of the porous structure.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The present invention starts from the target performance of the porous structure and performs controllable optimization of the pore structure according to the simulation results, thereby achieving the best target performance, realizing that each local pore structure is obtained through controllable design optimization, and avoiding uncontrollable random structure;

[0035] (2) The method provided by the present invention can realize the controllable optimization design of various complex multi-level pore structures. The obtained porous structure parameters are stable and have very strong repeatability in the subsequent porous structure preparation process, and its optimal target performance can be well guaranteed. At the same time, according to the change of actual operating conditions, the pore structure can also be easily regulated and designed again, so that it can achieve the optimal target performance under the new operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is the preliminary porous structure constructed in Example 1;

[0037] Figure 2 is the relationship between the space-time yield and the pore size simulated in Example 1;

[0038] Figure 3 It is the preliminary porous structure constructed in Example 2;

[0039] Figure 4 is the relationship between the reactant conversion rate and the pore size simulated in Example 2;

[0040] Figure 5 is the optimized porous structure constructed in Example 2;

[0041] Figure 6 is the relationship between the product selectivity and the pore size simulated in Example 2;

[0042] Figure 7 D constructed in Example 3 1 =1.23, D 2 =9.85, D 3 =24.63 channel connection method;

[0043] Figure 8 D constructed in Example 3 1 =1.23, D 2 =9.85, D 3 =49.26 channel connection method;

[0044] Fig. 9 D constructed in Example 3 1 =4.94, D 2 =36.95, D 3 =98.52 channel connection method;

[0045] Fig.10 is the porous structure constructed in Example 4;

[0046] Fig.11 In Example 4, D is maintained 1The relationship between the time-space yield of the target product and the porosity when the porosity remains unchanged;

[0047] Fig.12 In Example 4, D is maintained 1 The relationship between the conversion rate of reactants and the porosity when the reaction rate is constant;

[0048] Fig.13 In Example 4, D is maintained 2 With D 3 The relationship between the time-space yield of the target product and the porosity when the porosity remains unchanged;

[0049] Fig.14 In Example 4, D is maintained 2 With D 3 The relationship between the conversion rate of reactants and the porosity when the reaction rate is constant;

[0050] Fig.15 In Example 4, D is maintained 1 With D 2 The space-time yield of the target product changes with the pore size D 3 The changing relationship of

[0051] Fig.16 In Example 4, D is maintained 1 With D 2 When the reactant conversion rate is constant, the pore size D 3 of the changing relationship. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0053] The construction program of the porous structure in the following embodiments is a parallel computing program based on a CPU platform, and the specific calculation process includes the following steps:

[0054] (1) Based on the type and function of the porous structure to be constructed, provide the total volume, porosity, and overall geometric shape and parameters of the pore structure, such as cube (side length), cuboid (length, width, height), sphere (radius or diameter), or other shapes (corresponding description parameters);

[0055] (2) Based on the complexity of the pores and the actual conditions of different pore structures, provide parameters describing the pores, such as basic crystal structure, average pore size or precise pore size distribution (pore size and corresponding volume percentage), number (density) and distribution position of functional sites, and the opening and closing of the pores;

[0056] (3) Using a calculation program, first generate the coordinate range of a given shape and volume according to the above parameters, and divide this coordinate range into cuboid or cube meshes of a certain size (the maximum side length of the mesh does not exceed the minimum pore diameter). Then, map the complex pore structure to the mesh according to the parameters, and mark the mesh as belonging to the pore or the solid; all the meshes together constitute the pore structure. The constructed pore structure can be a pore structure formed by arranging and stacking discrete particles (position coordinates), or a structure described by geometric parameters (points, lines, surfaces, and volumes), and finally form a coordinate data file with attribute marks.

[0057] In the following embodiments, the above calculation program is simply referred to as "Program A".

[0058] In the following embodiments, the program for simulating the coupling process of adsorption, reaction, and diffusion of each component in the pore is a parallel calculation program based on the CPU platform. The specific simulation process is as follows:

[0059] Based on the reaction process of the embodiment, provide the path network where the reaction occurs and the energy barrier for each path to occur. According to the chemical reaction collision theory, when two components interact, if their energy parameters meet the conditions for the reaction to occur, the reaction occurs; otherwise, the reaction does not occur. For each reaction that occurs, a reaction "event" is formed in the program, and this event can be coupled with the program and algorithm to realize the simulation of the coupling process of adsorption, reaction, and diffusion.

[0060] In the following embodiments, the above simulation process is simply referred to as "Program B".

[0061] Example 1

[0062] This embodiment provides a method for controllable design of a porous structure based on computer simulation. The method for controllable design of the porous structure realizes the regulation and design of the optimal pore diameter by specifying the porosity and the connection mode of the pores. The specific process is as follows:

[0063] (1) Use Program A to construct a porous structure with a porosity ε and including a given pore size distribution. As Figure 1 shown, the overall shape of the porous structure is a cube with a side length of 36.

[0064] (2) The parameters describing the target performance of the porous structure are the pore diameter d and its corresponding volume fraction n. Both the pore diameter d and the volume fraction n can be regulated. When the pore diameter d is regulated to vary within a given reasonable range (0 < d < 10), the pore diameters of all the pores always remain equal. All the parameters in this example are dimensionless values.

[0065] (3) The functional sites in the pore channels are chemically reactive sites, which are uniformly distributed on the inner surface of the porous structure. Reaction processes can occur at these sites, and the reaction process can be simplified as a process where reactant A reacts with the sites to form product B (A → B). Each component can freely enter and exit through the pore openings;

[0066] (4) During the adjustment and optimization process, the value of the pore diameter d is changed for simulation while keeping the total pore volume V and the porosity ε unchanged. The target performance parameter is the space-time yield Y of product B. The optimization goal is to maximize the space-time yield Y of product B. Program B is used to simulate the coupled reaction and diffusion processes of each component in the pore channels, and then the Y values under different pore diameter d distributions are statistically obtained.

[0067] Figure 2 One of the simulation results is given, showing the relationship between Y and the pore diameter d when the porosity ε is 0.234. The results show that when the pore diameter d is 1.5 (dimensionless value), Y reaches the maximum value. At this time, the corresponding pore diameter distribution is the optimal pore structure under the given constraints, and the Y value at this time is much higher than the Y value obtained by simulating a pore structure with a random pore diameter (i.e., the diameter of each pore is a random value within a given range) with the same porosity (see "completely random" in Figure 2 ), thus realizing the controllable optimization design of the porous structure.

[0068] Example 2

[0069] This example provides a method for controllable design of a porous structure based on computer simulation. The method for controllable design of the porous structure realizes the regulation and design of the optimal pore diameter by specifying the porosity and with a random pore connection mode. The specific process is as follows:

[0070] (1) Use program A to construct a porous structure with a porosity ε and a complex pore diameter distribution, as Figure 3 shown. The overall shape of the porous structure is a sphere. The basic structure of the sphere is the SAPO-34 molecular sieve crystal structure (micropore diameter 1.033), with a diameter of 50. On this basis, an internal pore channel structure is constructed, and the pore connection mode is random;

[0071] (2) The parameters describing the target performance of the porous structure are the pore diameter d and its corresponding volume fraction n, and the active site distribution. Both the pore diameter distribution and the active site distribution can be regulated. When the pore diameter d is changed within a given reasonable range (5 < d < 12), the porosity ε is always kept at 0.35 unchanged, and the pore diameters of all pore channels are equal. All parameters in this example are dimensionless values;

[0072] (3) The functional sites in the pores are chemically reactive sites and are evenly distributed on the inner surface of the porous structure. The reaction process occurring at the sites proceeds as follows, where each letter represents a component:

[0073] A+F→D+G

[0074] A+G→D+H

[0075] A+H→D+I

[0076] H+E→F+B

[0077] I+E→F+C

[0078] Among them, A is the reactant, B and C are the target products, and the rest are intermediate components or by-products; each component has its own properties such as mass and radius, and can freely enter and exit from the opening of the channel;

[0079] (4) In the process of adjustment and optimization, the numerical value of the pore size d is changed for simulation, while the overall shape and porosity ε of the porous structure are kept unchanged. The parameter of the target performance is the conversion rate of the reactant A, and the optimization goal is to maximize the conversion rate of A. Program B is used to simulate the reaction and diffusion coupling process of each component in the pore channel, and the connection of the pore channel is regulated according to the coupling coordination of reaction and diffusion and the optimization of local target performance, and then the conversion rate of the reactant A under different pore size d distributions is statistically obtained.

[0080] like Figure 4 As shown in the results, the conversion rate of reactant A reaches the maximum value when the pore diameter d is 13.1. At this time, the schematic diagram of the cross-section of the porous structure with the best target performance under given constraints is shown in Figure 5 shown.

[0081] Similarly, in this embodiment, if the target performance parameter is the selectivity of product C, and the optimization goal is to maximize the selectivity of C, then after simulation, the relationship between the selectivity of product C and the pore size d is as follows: Figure 6 As shown, the results show that the selectivity of product C reaches a maximum value when the pore size d is 10.4, and the porous structure obtained at this time is the structure with the best target performance under given constraints.

[0082] Example 3

[0083] This embodiment provides a method for controllable design of porous structures based on computer simulation. The method for controllable design of porous structures achieves the controllable design of optimal pore size distribution and pore connection mode by giving a given porosity. The specific process is as follows:

[0084] (1) Using program A to construct porous structures with porosity ε and different pore connection modes;

[0085] (2) The porous structure contains three types of pores with different pore sizes: macropores, mesopores and micropores. The pore connection mode can be adjusted. The parameter describing the pore structure is the pore size D 1 , D 2 , D 3 ,…,D n As well as the corresponding volume proportion n, the distribution of active sites and the connection mode of the pores; a porous structure with an overall cubic shape is constructed, with a side length of 123 and a porosity of 0.36, and all of them contain tertiary pores (pore size D 1 ≤D 2 ≤D 3 ), the connection mode between the channels can be adjusted, and all parameters in this example are dimensionless values;

[0086] (3) The functional sites in the pores are chemically reactive sites and are evenly distributed on the inner surface of the porous structure. The reaction process occurring at the sites can be simplified as A→B+C+D, where A is the reactant, B and C are both target products, and D is the by-product. Each component has its own properties such as mass and radius, and can freely enter and exit the pore opening.

[0087] (4) During the adjustment and optimization process, the overall shape and porosity ε of the porous structure are kept unchanged, and all contain a three-level pore structure (pore size D 1 ≤D 2 ≤D 3 ), regulating the connection mode between the channels and the corresponding pore size; the parameters of the target performance include: (A) the conversion rate of reactant A, (B) the space-time yield of the target product; the optimization goal is to maximize the conversion rate of reactant A while also achieving a large space-time yield of the target product.

[0088] Based on the above steps, this embodiment constructs structures with three different channel connection modes, and their two-dimensional schematic diagrams are as follows: Figure 7 , Figure 8 and Fig. 9 As shown, Figure 7 Structure of D 1 =1.23, D 2 =9.85, D 3 =24.63; Figure 8 Structure of D 1 =1.23, D 2 =9.85, D 3 =49.26; Fig. 9 Structure of D 1 =4.94, D 2 =36.95, D 3 =98.52.

[0089] Program B was used to simulate the reaction and diffusion coupling process of each component in the pores. The pore connection and pore size were regulated according to the coupling coordination of reaction and diffusion and the optimization of local target performance. The conversion rates of reactant A corresponding to the three structures obtained after regulation were 0.4963, 0.4416 and 0.3315 respectively; the time-space yields of the target products were 3.1832, 2.7715 and 3.0969 respectively. The results show Figure 7 If the pore connection mode meets the optimization goal, the porous structure obtained at this time is the structure with the best target performance under given constraints.

[0090] Example 4

[0091] This embodiment provides a method for controllable design of porous structures based on computer simulation. The method for controllable design of porous structures achieves the controllable design of optimal porosity and pore size distribution by giving a given pore connection mode. The specific process is as follows:

[0092] (1) Use program A to construct complex porous structures, such as Fig.10 As shown, the porous structure has a porosity ε and contains pores with different pore sizes;

[0093] (2) The pore size of the porous structure is D 1 The pores of the primary channel structure are composed of a pore size of D 2 The secondary pore structure is composed of a pore size of D 3 The three-level pore structure, and so on, forms a complex pore structure; the parameter describing the pore structure is the pore diameter D 1 , D 2 , D 3 …D n As well as the corresponding volume proportion n and active site distribution; construct a porous structure with an overall cubic shape, a side length of 246, a porosity adjustable between 0.15-0.5, and a three-level pore (pore size D 1 ≤D 2 ≤D 3 ), the aperture of each level can be adjusted, and all parameters in this example are dimensionless values;

[0094] (3) The functional sites in the pores are chemically reactive sites and are evenly distributed on the inner surface of the porous structure. The reaction process occurring at the sites can be simplified as A→B+C+D, where A is the reactant, B and C are the target products, and D is the by-product. Each component has its own properties such as mass and radius, and can freely enter and exit the pore opening.

[0095] (4) During the adjustment and optimization process, the overall shape and pore connection mode of the porous structure are kept unchanged, and all contain a three-level pore structure (pore size D1 ≤D 2 ≤D 3 ), regulating the porosity ε and the pore size of each level; the parameters of the target performance include (A) the conversion rate of reactant A, and (B) the space-time yield of the target product; the optimization goal is to maximize the conversion rate of reactant A while also achieving a large space-time yield of the target product. Program B is used to simulate the reaction and diffusion coupling process of each component in the pore.

[0096] In this embodiment, when D is maintained 1 =1.23, by adjusting D 2 and D 3 And the corresponding volume proportion n, to achieve the regulation of porosity ε, the results are as follows Fig.11 and Fig.12 As shown, it can be seen that within the reasonable control range of porosity ε, increasing the porosity ε can increase both the conversion rate and the space-time yield.

[0097] In this embodiment, when D is maintained 1 and D 3 When the corresponding volume ratio n remains unchanged, only D is adjusted 2 The size of Fig.13 and Fig.14 As shown, it can be seen that D 2 The size of the hole has almost no effect on the performance.

[0098] In this embodiment, when D is maintained 1 and D 2 When the corresponding volume ratio n remains unchanged, only D is adjusted 3 The size of Fig.15 and Fig.16 As shown, it can be seen that the maximum aperture D is reduced 3 Can make the target performance reach the optimal value, and D 3 The target performance has an optimal value between 4.9 and 12.3.

[0099] Therefore, through the above simulation, a porous structure with optimal target performance under given constraints can be obtained, thereby achieving controllable design of the porous structure.

[0100] In summary, the present invention starts from the target performance of the porous structure, and optimizes the pore structure in a controllable manner according to the simulation results, thereby achieving the best target performance, and realizing that each local pore structure is obtained through controllable design optimization, avoiding uncontrollable random structures; in addition, the method provided by the present invention can realize controllable optimization design of various complex multi-level pore structures, and the obtained porous structure parameters are stable, and have very strong repeatability in the subsequent porous structure preparation process, and its optimal target performance can be well guaranteed. At the same time, according to the changes in actual operating conditions, the pore structure can also be easily regulated and designed again, so that it can achieve the best target performance under new operating conditions.

[0101] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A controllable design method for porous structures based on computer simulation, characterized in that: The controllable porous structure design method comprises the following steps: (1) constructing a preliminary porous structure based on the type and function of the target structure; the overall shape of the porous structure is a sphere or an irregular shape; (2) Establish computational models based on physical processes and chemical reactions; (3) quantitatively characterizing the target performance of the porous structure obtained in step (1), and performing simulation calculations using the calculation model obtained in step (2) to obtain simulation results; the target parameters obtained after the quantitative characterization of the target performance can be used to characterize the target performance of the entire or local porous structure; (4) According to the simulation results obtained in step (3), the porous structure obtained in step (1) is adjusted and optimized to obtain an optimized porous structure, and the simulation calculation of step (3) is performed again; the adjustment and optimization is based on the principle of diffusion-reaction coupling coordination; the direction of the adjustment and optimization is to maximize or minimize the target performance of step (3); (5) When the simulation result obtained in step (3) reaches the optimal solution, the porous structure obtained in step (4) is the porous structure with the best target performance, which is saved to guide the subsequent processing and preparation of the porous structure.

2. The controllable design method of porous structure according to claim 1, characterized in that: The porous structure in step (1) has a non-functional matrix or is entirely composed of functional components.

3. The controllable design method of porous structure according to claim 1, characterized in that: The characteristic parameters set in the porous structure of step (1) during the construction process include any one or a combination of at least two of the porosity, pore size, pore size distribution, pore opening and closing, pore connection topology, functional site content, functional site distribution or doping component distribution.

4. The method for controllable design of porous structure according to claim 1, characterized in that: The physical process in step (2) includes any one of diffusion, adsorption or desorption, or a combination of at least two of them.

5. The controllable design method of porous structure according to claim 1, characterized in that: The chemical reaction in step (2) includes any one of a combination reaction, a decomposition reaction, a replacement reaction, a double decomposition reaction, a substitution reaction, an addition reaction, an elimination reaction, a pericyclic reaction, a rearrangement reaction or a redox reaction, or a combination of at least two thereof.

6. The method for controllable design of porous structure according to claim 1, characterized in that: The simulation parameters set in the computational model of step (2) during the establishment process include any one or a combination of at least two of the mass of each component, atomic composition, equivalent diameter of atoms or molecules, reaction temperature, reaction pressure, initial conditions, boundary conditions, chemical reaction pathways, chemical reaction networks, energy transfer or conversion pathways.

7. The controllable design method of porous structure according to claim 1, characterized in that: The target parameters obtained after quantitative characterization of the target performance in step (3) include any one or a combination of at least two of the reaction performance, diffusion performance, time-space yield of the product, product selectivity, conversion rate of the reactant, adsorption rate or adsorption amount of each component in the porous structure.

8. The method for controllable design of porous structure according to claim 1, characterized in that: The controllable porous structure design method comprises the following steps: (1) constructing a preliminary porous structure based on the type and function of the target structure; the porous structure has a non-functional matrix or is entirely functional components, and the overall shape is a sphere or an irregular shape; the characteristic parameters set in the porous structure during the construction process include any one or a combination of at least two of porosity, pore size, pore size distribution, pore opening and closing, pore connection topology, functional site content, functional site distribution or doping component distribution; (2) establishing a computational model based on physical processes and chemical reactions; the physical process includes any one of diffusion, adsorption or desorption or a combination of at least two of them; the chemical reaction includes any one of combination reaction, decomposition reaction, replacement reaction, metathesis reaction, substitution reaction, addition reaction, elimination reaction, pericyclic reaction, rearrangement reaction or redox reaction or a combination of at least two of them; the simulation parameters set in the computational model during the establishment process include any one of the mass of each component, atomic composition, equivalent diameter of atoms or molecules, reaction temperature, reaction pressure, initial conditions, boundary conditions, chemical reaction path, chemical reaction network, energy transfer or conversion path or a combination of at least two of them; (3) quantitatively characterizing the target performance of the porous structure obtained in step (1), and performing simulation calculations using the calculation model obtained in step (2) to obtain simulation results; the target parameters obtained after the quantitative characterization of the target performance include any one or a combination of at least two of the reaction performance, diffusion performance, spatiotemporal yield of the product, selectivity of the product, conversion rate of the reactant, adsorption rate or adsorption amount of each component in the porous structure; the target parameters obtained after the quantitative characterization of the target performance can be used to characterize the target performance of the entire or local porous structure; (4) Based on the principle of diffusion-reaction coupling coordination, the porous structure obtained in step (1) is adjusted and optimized according to the simulation results obtained in step (3) to obtain an optimized porous structure, and the simulation calculation of step (3) is performed again; the direction of the adjustment and optimization is to maximize or minimize the target performance of step (3); (5) When the simulation result obtained in step (3) reaches the optimal solution, the porous structure obtained in step (4) is the porous structure with the best target performance, which is saved to guide the subsequent processing and preparation of the porous structure.

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