The Micro-kinetic Study In The Process Of Chemical Reaction And Structure Optimization

In addition to the traditional chemical experiment methods,numerical calculation and simulation is another important and essential method in modern chemical science research.This paper focuses on the micro-dynamics simulation and calculation in the process of chemical reaction and cluster structure optimization,and the mainly narrated research contents focus on three aspects.In the first part,a kinetic Monte Carlo method based on the graph isomorphism theory is proposed,and a continuous change cell matrix is used to record and express the surface topography of the lattice surface,which is combined with the digital matrix expression of the primitive reaction.This method can quickly deal with the key problems of reaction channel selectivity of chemical reaction,which has the advantages of easy realization,high numerical efficiency and strong universality,and can be used to simulate reaction networks and selectivity of heterogeneous reactions catalyzed by different kinds of lattice surfaces.By using this method,the reaction of CO oxidation on the surface of Nano porous gold(Nano porous Gold,abbreviated NPG)is simulated.Through numerical experiments,it is found that the most important factor determining the catalytic oxidation reaction path is the partial pressure ratio of CO to O2,the greater the ratio,the more favorable to the tri-molecule reaction,The secondary factor affecting the catalytic oxidation reaction path is temperature,the lower the temperature,the more favorable to the tri-molecule reaction.The most important factor influencing the CO2 generation efficiency is the temperature of reaction environment,the higher the temperature,the higher the CO2 efficiency.The second study is to compare the efficiency of three kinds of surfactants used in oil production in petrochemical industry by using molecular dynamics method,and further study the influence of substrate polar and water phase flow on the formation and expansion of water molecule channel.The numerical simulation results show that the performance of SDBS surfactants is better than that of DTAB and OP-10 surfactants,and the substrate polarity plays a key role in the formation and expansion of water molecular channels,and the flow of water phase will suppress the formation and expansion of water molecule channels to different extents.The third study focuses on the calculation of the ligand layer structure and the gold-sulfur skeleton structure of a kind of sulfur-alcohol ligand-protected gold nano clusters.A kind of genetic algorithm based on molecular force field is developed,which can quickly search the structure of nano-cluster ligand,and it is better than the general L-J sorting algorithm.The comparison results show that the genetic algorithm based on the Molecular force field is 7-9 times more efficient than the conventional L-J sorting algorithm.The structure model of Au22(SR)18 clusters is predicted by using the method of "decomposition-assembly",combining molecular mechanics calculation,density functional theory calculation and molecular orbital analysis.From the angle of molecular orbital analysis,the source of electron stability of the cluster is discussed,and the electron distribution in the cluster shows the characteristics of "super atom"electron structure.