Pt_(3)Co高指数晶面氧还原过程的密度泛函理论研究  

Oxygen Reduction Reaction on Pt_(3)Co High-index Facets by Density Functional Theory

作　　者：刘磊 郭瑞华[1,2,3] 王丽 王艳[5] 张国芳[1] 关丽丽[1,2] LIU Lei;GUO Ruihua;WANG Li;WANG Yan;ZHANG Guofang;GUAN Lili(School of Materials Science and Engineering,Inner Mongolia University of Science&Technology,Baotou 014010,China;Inner Mongolia Key Laboratory of Advanced Ceramic Materials and Devices,Inner Mongolia University of Science&Technology,Baotou 014010,China;Key Laboratory of Green Extraction&Efficient Utilization of Light Rare-Earth Resources,Ministry of Education,Inner Mongolia University of Science&Technology,Baotou 014010,China;School of Chemistry and Chemical Engineering,Inner Mongolia University of Science&Technology,Baotou 014010,China;Baotou Research Institute of Rare Earths,Baotou 014020,China)

机构地区：[1]内蒙古科技大学材料科学与工程学院,包头014010 [2]内蒙古科技大学内蒙古自治区先进陶瓷材料与器件重点实验室,包头014010 [3]内蒙古科技大学轻稀土资源绿色提取与高效利用教育部重点实验室,包头014010 [4]内蒙古科技大学化学与化工学院,包头014010 [5]包头稀土研究院,包头014020

出　　处：《无机材料学报》2025年第1期39-46,I0001-I0005,共13页Journal of Inorganic Materials

基　　金：国家自然科学基金(51864040,51962028,52162010);内蒙古自治区科技计划(2021GG0042);内蒙古自治区高等学校青年科技英才(NJYT22064);内蒙古自治区自然科学基金(2022MS05018,2022LHMS05021)。

摘　　要：Pt_(3)Co催化剂是Pt基合金中氧还原反应(ORR)活性最高的催化剂,合成Pt_(3)Co高指数晶面(HIFs)是一种提高其催化性能的有效策略,但具有最高ORR活性的HIFs尚未明确,并且目前缺乏对Pt_(3)Co HIFs ORR的系统研究。本研究构建了六种不同Pt_(3)Co HIFs,通过从头算分子动力学(AIMD)计算证明了其稳定性,通过密度泛函理论(DFT)计算了六种Pt_(3)Co HIFs的ORR过程中间物*O、*OH、*OOH的结合能(BE),通过d带中心(εd)、Bader电荷及配位数(CN)解释了其在台阶与边缘位点BE不同的原因。同时分析了吸附原子CN与εd的关系,通过ORR自由能台阶图分析了ORR过程中的过电位(η),发现η大小主要与*OH结合能(BE-*OH)有关,其中η最小的晶面为Pt_(3)Co(211),其在台阶处的η达到了0.294 eV。本工作为高ORR活性HIFs催化剂研发提供了一定的理论依据。Pt_(3)Co catalyst is the most active catalyst for oxygen reduction reaction(ORR)in Pt based alloys,in which synthesis of Pt_(3)Co high-index facets(HIFs)is an effective strategy to improve its catalytic performance.However,HIFs possessing the highest ORR activity have not yet been clarified,and at present,there is a lack of a systematic study on the ORR of Pt_(3)Co HIFs.In this study,six different Pt_(3)Co HIFs were constructed,and their stability was proved through ab initio molecular dynamics(AIMD)calculations.Binding energies(BE)of*O,*OH and*OOH intermediates for the six Pt_(3)Co HIFs during ORR process were calculated by density functional theory(DFT),and d-band center(εd),Bader charge and coordination number(CN)were used to explain the different binding energies at terrace and edge sites.Relationship between CN of adsorbed atoms andεd was also analyzed.Overpotential(η)during ORR was analyzed through ORR free energy step diagram,and it revealed that the magnitude ofηwas mainly related to*OH binding energy(BE-*OH).The Pt_(3)Co(211)facet has the smallestη,which at the Pt_(3)Co(211)terrace site reaches 0.294 eV.Therefore,this work provides a sound theoretical basis for the development of high ORR activity HIFs catalysts.

关 键 词：Pt_(3)Co催化剂 高指数晶面 密度泛函理论 氧还原反应 

分 类 号：TM911[电气工程—电力电子与电力传动]