Development Of Reaction Force Field For Fe-O-H System And Its Application In The Water Splitting Reaction

In recent years,with the increasing demand for clean energy such as hydrogen energy in human society,the research on the heterogeneous catalytic reaction mechanism for hydrogen production by hydrogenation and carbon dioxide reduction has received increasing attention.First-principles method based on density functional theory(DFT)can analyze the electronic structure and catalytic activity of catalytic materials from the perspective of thermodynamics.In the study of the kinetics of the catalytic reaction,the DFT method is limited by the scale of the research system and the setting of the reaction conditions,making it impossible to accurately obtain the kinetic characteristics such as the reaction pathway,intermediate products,and active site changes.As a new generation of force field method,ReaxFF reaction force field can handle larger systems and condensed phases under limited computer resources.Based on the ReaxFF reactive force field method,the chemical reaction process in a reactive molecular system can be simulated without pre-defining the chemical reaction path,the kinetic parameters of the catalytic reaction can be more closely and truly studied.In this study,the development of the ReaxFF force field of Fe-O-H system is taken as the main line,involving the detailed process and method of force field development.The developed Fe-O-H reaction force field was used to study the surface hydrolysis of Fe2O3 and to form Dynamics cognition.The first chapter of this paper mainly introduces the basic principle of ReaxFF force field and its various applications,related parameters,relevant theories involved,and briefly summarizes the force field development process.In the second chapter,the development of the force field of the Fe-O-H system is described in detail.Based on the first-principles calculations,the training set required for the development of the force field has been prepared,parameters was fitted,and finally obtained the force field potential function file.In the third chapter,we simulate the process of adsorption and desorption of water at the surface of Fe2O3 under different external conditions.The accuracy of the force field potential function of the Fe-O-H system is verified.In the fourth chapter,the work of the thesis is reviewed and summarized.