Density Functional Theory Study On Local Chemical Environment Affecting Catalytic Process

Catalytic conversion of energy is one of the effective means to solve the energy crisis.Density Functional Theory（DFT）calculation can deeply understand the reaction mechanism,reveal the underlying physical and chemical reasons,and plays a more and more significant role in screening and designing catalysts.However,many efforts are urgently needed in the cognition of the catalytic interface and relevant calculation methods to better understand and analyze the experimental phenomena.In this paper,the local environmental factors affecting the catalytic reactions were explored from various aspects.The effects of catalyst surface structure,electronic structure and coordination environment,electrolyte cations and solution environment on the catalytic reactions were studied,and the treatment method of solvent in DFT simulation were proposed.The conclusions obtained are as follows:The reaction of CO₂ reduction to methanol on Cu/Zn O was studied.It was found that the surface coordination environment can affect the configuration of reaction intermediates and reaction path.This work also proves that the Cu/Zn O interface structure with kink defects and exposed heterointerface are the active sites,and optimal path is reverse water gas shift（RWGS）+CO hydrogenation.The work function,orbitalwise coordination number and surface coordination unsaturation are combined as a descriptor for surface adsorption energy.The descriptor can well describe the adsorption energy of different adsorbates on different crystal facets of different transition metals.In this way,the catalytic performance of the material is directly related to its intrinsic properties,which can significantly save the DFT calculation cost.The possible influence of cations on electrocatalytic reaction was studied through the ab-initio molecular dynamics simulation and the derivation of the ideal gas model.We draw the conclusion that there will be a large density of cations at the solid-liquid interface in the reduction reactions and part of oxidation reactions,which indicates the possible strong cation effect in the catalytic process.An explicit and implicit hybrid solvent model based on ab-initio molecular dynamics（AIMD）simulation is developed to explore the possible effect of hydrogen bond network on chemical reactions in aqueous solution.The problem of entropy divergence of water in MD is solved using force covariance matrix.