子表面反应物在铁基催化剂表界面扩散机制研究

项目名称： 子表面反应物在铁基催化剂表界面扩散机制研究

项目编号： No.21506053

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 有机化学

项目作者： 沈祥建

作者单位： 郑州大学

项目金额： 21万元

中文摘要： 介质在催化剂表界面的传递是十分普遍的，但在实际高温高压反应条件下，由于催化剂表界面结构演变具有显著性（时间尺度快），并发生在分子层面上（空间尺度小），现有动态现场原位实验技术只能捕捉到十分有限的反应信息，无法取得全面实时的动态信息，更无法跟踪介质尤其是子表面反应物在催化剂表界面相间的扩散路径。本项目拟通过密度泛函理论计算结合分子动力学模拟方法来探索反应物在不同铁基催化剂表界面相间的扩散，重点研究影响子表面反应物碳氢原子或基团等在催化剂表界面扩散过程中的关键性热力学和动力学因素，尝试提出含子表面反应物参与的新反应机制并验证其适用性。大尺度分子动力学方法模拟子表面反应物在催化剂表界面的扩散过程，不但为深入研究铁基FTO反应展示重要的热力学信息和强劲的动力学模拟依据，还为动态现场原位实验提供精确的微观解释，并进一步加深理解介质在催化剂表界面的传递机制。

中文关键词： 子表面反应物；铁基催化剂；扩散机制；密度泛函理论；分子动力学模拟

英文摘要： Mass transfer on the surface/interface of catalyst is very general, however, under real high temperature and high pressure reaction conditions, current Operando experimental techniques only capture very limited reaction information, without obtaining full and in-time dynamical information, thus it is hard to track the diffusion pathways of subsurface reactants on surface/interface of catalyst. It is mainly due to the obvious catalyst surface/interface structural evolution (fast in time-scale) and reacting on the molecular level (small in space-scale). In the present proposal, we will investigate reactants diffusing on the surface/interface of different iron-based catalysts by method of combining density functional theory (DFT) calculation with molecular dynamics (MD) simulation. Some significant thermal and dynamical effects about subsurface reactants, ex., carbon hydrogen atoms or groups and so on, will be emphasized so that we will propose a new reaction mechanism containing subsurface reactants and further to validate its application. Simulating such diffusion process about subsurface reactants on the surface/interface of catalysts by using a large-scale molecular dynamics method, it would not like to only demonstrate important thermal information and powerful dynamical evidences on deeply studying the iron-based FTO reaction, but also to provide precise microscopic explanations for some Operando experiments, as well as further to enhance the understanding of mass transfer mechanism on the surface/interface of catalysts.

英文关键词： subsurface reactants;iron-based catalyst;diffusion mechanism;density functional theory;molecular dynamics simulation