The Adsorption Of CO And O On Transition Metal Catalysts:a DFT Research

The adsorption of CO on transition metal surfaces have great significance when it comes to catalytic process involve CO.Understanding the adsorption behavior of adatoms on metal surfaces would be very useful in understanding a variety of electrochemically and heterogeneously catalyzed reactions.For this reason,a large amount of detailed research has been performed on these processes.For transition metal system,because it contains many electrons,electronic effect is noticeable,using methods including electronic related function calculation is necessary,it can obtain more reliable total energy and geometric configurations.The appearance of molecular simulation means that it is possible to study the mechanism of small molecule adsorption on the transition metal surface from the microscopic perspective,and to design better transition metal catalyst from the macro perspective.In this paper,density function theory was introduced,several reactions that catalyzed by transition metals and studies of transition metal catalyst using DFT(Density Function Theory)method were reviewed,solutions and methods using molecular simulation to design transition metal catalyst were provided.Density function theory were used to calculate the adsorption and oxidation of carbon monoxide on Pd(111),Pd(110),Pd(100),Au(111),Au(110)and Au(100)surfaces.We Adsorption configurations and adsorption energies were analyzed,we found that O adsorb steadily on the three fold hollow site of(111)surfaces,CO can adsorb steadily on low index Pd surfaces,but has little interaction with Au surfaces.Pre-adsorbed O can increase the adsorption energy of CO.Therefore,partly oxidating Pd and Au or loading Pd,Au particle onto oxide support can increase the catalytic oxidation capacity for metal surfaces.First Princple Theory was also used to analysis the formation energy of nAu/Pd(111)(n=1,2,3,4)alloy surfaces and the adsorption energy of O,CO on the surfaces.We found that 1Au/Pd(111)posses the highest surface formation energy,is the most stable surface.And the less the Au/Pd is,the stronger the intraction between O and CO,the more the adsorption energy,thus the higher the reactivity.In the meantime,the design of Au/Pd bimetallic surfaces can restrain CO poisoning.The results of this paper is helpful to design better transition metal catalyst,and has a certain guiding role to the catalyst design of CO oxidation reaction,hydrogen production,fuel cell reaction and automobile exhaust treatment(CO converter).