基于密度泛函理论的S掺杂碳载体负载Pt催化剂对氧还原反应的影响  

Effects of the S-Doped Carbon Supported Pt Catalyst on Oxygen Reduction Reaction by Density Functional Theory

作　　者：叶蔚甄 任强 王春璐 曲亚坤 YE Weizhen;REN Qiang;WANG Chunlu;QU Yakun(SINOPEC Research Institute of Petroleum Processing Co.,Ltd.,Beijing 100083,China)

机构地区：[1]中石化石油化工科学研究院有限公司,北京100083

出　　处：《石油学报（石油加工）》2024年第4期931-941,共11页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：中国石油化工股份有限公司科技开发项目(421086-4)基金资助。

摘　　要：采用密度泛函方法对比研究了Pt/C催化剂中碳载体掺S前后对氧还原反应(ORR)的影响。从电荷分布、态密度及d带中心等性质出发,分析了金属-载体间相互作用,研究了ORR各物种在催化剂上的吸附并计算了ORR过电势。结果表明:S掺杂使得碳载体表面发生了电子转移,S上的电子转移到邻近的C原子上,负载Pt纳米颗粒后,Pt金属上的电子转移给了碳载体;Pt在S掺杂碳载体上的吸附更强,形成了Pt—C键和Pt—S键,Pt纳米颗粒的分散度和稳定性得到了提升;掺S使得催化剂d带中心下降,对ORR各中间体的吸附减弱,ORR过电势降低,表明掺S能提高催化剂的催化活性。The effects of S-doped and un-doped carbon supported Pt catalysts on oxygen reduction reaction(ORR)were studied by density functional theory.The metal-support interaction was analyzed from three aspects:charge distribution,density of states and d-band center.Moreover,the adsorption of ORR intermediates on catalysts was studied,and the overpotential of ORR was calculated.The results show that S-doping caused electrons transfer on the surface of carbon carrier,and the electrons on S were transferred to adjacent C atoms.After loading Pt particles,the electrons on Pt metal were transferred to carbon carrier.This also suggests that the adsorption of Pt on S-doped carbon carrier is stronger,thus forming the Pt—C and Pt—S bonds,and further enhancing the dispersion and stability of Pt nanoparticles.Then S-doping lowers d-band center of the catalyst,thus weakening the adsorption of ORR intermediates,and decreasing the overpotential of ORR,which indicates that the catalytic activity of catalyst can be improved by doping S.

关 键 词：S掺杂 Pt基催化剂 氧还原反应 密度泛函理论 态密度 d带中心 过电势 

分 类 号：O641[理学—物理化学]