整体型催化剂的微观结构数值化重构及其在反应-扩散过程多尺度建模中的应用

在研究气固催化反应中扩散时，传统方法一般对催化反应床层进行结构简化，很少涉及催化剂的微观结构以及活性组分分布对反应-扩散的影响，导致数学模型的精确度不高，且不能指导催化剂微观结构的改进。本项目书拟以用于汽车尾气处理、VOCs催化燃烧以及甲烷催化燃烧的贵金属催化剂和多组分六铝酸盐非贵金属催化剂作为研究对象，采用多种现代物理表征手段获取整体型催化剂二维和三维的显微观结构以及表面形貌，利用相位函数或等效孔道网格模型以及概率密度分布函数来重构得到描述催化剂孔道结构的数值化(或离散化)方程，建立整体型催化剂的反应-扩散数学模型，揭示催化剂的微观形貌以及表面组成分布对催化性能的定量信息，从而指导催化剂微观结构以及表面组成的精确设计。本项目书首次将图像数值化技术应用于多组分整体型催化剂微观结构重构，对多组分整体型催化剂微观结构及组分分布和反应-扩散过程之间的构效关系进行精细化模拟具有很强的创新性。

When modeling phenomena within porous catalyst particles, one has to describe a number of simultaneous processes. A fundamental understanding of catalytic reactions, i.e., cleavage and formation of chemical bonds, can only be achieved with the aid of quantum mechanics and statistical physics. An important subproblem is the description of the porous structure of the support and its optimization with respect to minimum diffusion resistances leading to a higher catalyst performance. Another important subproblem is the nanoscale description of the nature of surfaces, surface phase transitions, and change of the bonds of adsorbed species. Due to the complex spatial structure and distribution of active phase, it is difficult to establish a universal reaction-diffusion multi-scale model from molecular level to nanoscale or millimeter scale. In this research plan, by analyzing the characterization results (such as SEM, TEM, XPS, NMR, et al) of catalyst surface and spatial structure; the microstructure of porous catalyst of methane combustion is reconstructed digitally; futhurover a reaction-diffusion multi-scale model is established based on the reconstructed microstructure for the monolithic catalytic reactor. The effects of catalyst microstructure on catalytic performance would be studied based on the multi-scale model, and the research results would be utilized for the precise design of catalyst microstructure.