Understanding the Effect of the Exchange-Correlation Functionals on Methane and Ethane Formation over Ruthenium Catalysts  

交换关联泛函近似方法对Ru催化剂上甲烷和乙烷形成的影响

作　　者：Chen Chen Minzhen Jian Jin-Xun Liu Wei-Xue Li 陈晨;简敏珍;刘进勋;李微雪(中国科学技术大学化学物理系,合肥230026)

机构地区：[1]Department of Chemical Physics,School of Chemistry and Materials Science,University of Science and Technology of China,Hefei 230026,China

出　　处：《Chinese Journal of Chemical Physics》2022年第4期619-628,I0017-I0037,I0149,共32页化学物理学报（英文）

基　　金：This work was supported by the Key Technologies R&D Program of China(No.2018YFA0208603);the National Natural Science Foundation of China(No.22172150 and No.91945302);the Chinese Academy of Sciences Key Project(QYZDJ-SSW-SLH054);the Start-up Funds of University of Science and Technology of China(No.KY2060000171);the National Natural Science Foundation of Anhui province(No.2108085QB62);USTC Research Funds of the Double First-Class Initiative(No.YD2060002012);K.C.Wong Education(No.GJTD-2020-15);highPerformance Computational Resources provided by the University of Science and Technology of China(http://scc.ustc.edu.cn)and Hefei Advanced Computing center.

摘　　要：Density functional theory(DFT)has been established as a powerful research tool for heterogeneous catalysis research in obtaining key thermodynamic and/or kinetic parameters like adsorption energies,enthalpies of reaction,activation barriers,and rate constants.Understanding of density functional exchangecorrelation approximations is essential to reveal the mechanism and performance of a catalyst.In the present work,we reported the influence of six exchange-correlation density functionals,including PBE,RPBE,BEEF+vdW,optB86b+vdW,SCAN,and SCAN+rVV10,on the adsorption energies,reaction energies and activation barriers of carbon hydrogenation and carbon-carbon couplings during the formation of methane and ethane over Ru(0001)and Ru(1011)surfaces.We found the calculated reaction energies are strongly dependent on exchange-correlation density functionals due to the difference in coordination number between reactants and products on surfaces.The deviation of the calculated elementary reaction energies can be accumulated to a large value for chemical reaction involving multiple steps and vary considerably with different exchange-correlation density functionals calculations.The different exchange-correlation density functionals are found to influence considerably the selectivity of Ru(0001)surface for methane,ethylene,and ethane formation determined by the adsorption energies of intermediates involved.However,the influence on the barriers of the elementary surface reactions and the structural sensitivity of Ru(0001)and Ru(1011)are modest.Our work highlights the limitation of exchange-correlation density functionals on computational catalysis and the importance of choosing a proper exchange-correlation density functional in correctly evaluating the activity and selectivity of a catalyst.

关 键 词：Density functional exchange-correlation approximation Adsorption energy Reaction energy Activation barriers Structural sensitivity 

分 类 号：O641.1[理学—物理化学] O621.251[理学—化学]