Catalysts Screening And Mechanism Exploration Based On Density Functional Theory

In the past ten years,density functional theory（DFT）had a rapid development in heterogeneous field,which could provide a deep insight for a reaction at molec-ular level.By combing with reaction mechanism and microkinetic model,the re-activity under a reaction condition can be obtained.Then,by constructing the lin-ear relationship,a full catalytic reaction can be reduced to one or a few determining parameters that were known as“descriptors”.This leads to a better understanding of catalytic reaction,which finally fulfills the computational design of catalysts.The first part of this paper describes a probability-based computational screen-ing study,which to some extent,eliminates the errors of screening process com-pared to traditional ones.The activity and selectivity of propane dehydrogenation（PDH）were constrained by an approximately linear relationship,which indicates the selectivity will decline with the rise of activity.Via a probability analysis,the adsorption energy of propene can serve as a descriptor for the whole performance of propane dehydrogenation.After our screening process and mechanism explora-tion,Pt₃In was found to have a considerable improvement in the propylene selec-tivity compared with pure Pt,while own a little activity loss.The first dehydro-genation step was found to be the rate-controlling step on most of the facets.The adsorption energies of propylene that play a key role in selectivity and activity were correlated with the d-band center,which can be used to tune a more precise PtIn ratio for PDH reaction in the future.The complex propane dehydrogenation reaction can be reduced to one or a few determining parameters,which facilitates the screening process for propane dehy-drogenation.Inspired by this,the second part of this paper tried to develop the relationship between ionization energy and adsorption energy to have a better un-derstanding of surface oxidation.Considering the similarity between ionization energy（IE）and oxidation reaction that they all contain the processes of losing electrons,the ionization energy was found to be correlated with the adsorption energy of O*and OH*on various catalyst materials.A bond formation scheme was then provided to interpret the corresponding physical insights:the numerical value of ionization energy of surface atoms determines its position of d band and the position of d band determines the filling of antibonding state after adsorbate-surface interaction.This descriptor has been extended to various oxides,metal,N-graphene and zeolites.More interestingly,this descriptor even doesn’t need any calculations of electronic structures.A framework for rationalizing activity trends of oxidation has been established,which enables the rational design of catalysts for selective oxidation of methane to methanol using this simple and universal descriptor.Our descriptor and model enable the computational design of catalysts for oxidation reaction in the future.