Co掺杂Pt(111)面水煤气变换反应机理的理论研究  

Theoretical Study on the Water Gas Shift (WGS) Reaction Mechanism of the Co-doped Pt (111) Surface

作　　者：丁浩然 姚陈忠[1] DING Haoran;YAO Chenzhong(Department of Applied Chemistry,Yuncheng University,Yuncheng 044000,China)

机构地区：[1]运城学院应用化学系,山西运城044000

出　　处：《忻州师范学院学报》2022年第2期15-18,43,共5页Journal of Xinzhou Teachers University

基　　金：NSFC-山西煤基低碳联合基金(U1810110)。

摘　　要：水煤气变换(WGS)是化工生产过程中的一个重要反应,近年来由于燃料电池行业的兴起,低温WGS反应催化剂的研发成为目前研究的热点之一。本文采用密度泛函理论对Pt(111)面催化WGS反应进行了系统研究。结果显示,H_(2)O的解离是WGS反应的关键步骤。低温时,WGS的主要反应路径为羧酸盐路径,即CO+2H_(2)O→CO+2OH+2H→COOH+OH+H_(2)→CO_(2)+H_(2)O+H_(2);高温反应时,反应路径主要为氧化还原路径:CO+2H_(2)O→CO+2OH+2H→CO+O+H_(2)O+H_(2)→CO_(2)+H_(2)O+H_(2)。表面掺杂Co后,由于Pt的电负性大于Co, Co原子的电荷向Pt原子转移。因此,Co掺杂可降低H_(2)O解离的能垒,从而提高WGS反应活性。Water-gas shift(WGS) is an important reaction in the chemical process.Low-temperature WGS reaction has become a hot topic due to the development of fuel cell industry now.In this paper, WGS reaction was systematically investigated on Pt(111) surface by using density functional theory.The results show that the dissociation of H_(2)O is a key pathway involved in the WGS reaction.At low temperature, the main reaction pathway of WGS is CO+2 H_(2)O → CO+2 OH+2 H → COOH+OH+H_(2)→ CO_(2)+H_(2)O+H_(2);The main reaction path at high temperature is CO+2 H_(2)O → CO+2 OH+2 H → CO+O+H_(2)O+H_(2)→ CO_(2)+H_(2)O+H_(2).Bader charge shows that the charge of Co atom transfers to Pt atom on Co-Pt(111) surface, because the electronegativity of Pt is larger than that of Co.In general, the energy barrier of H_(2)O dissociation decreases after Co doped Pt(111) surface, and the activity of WGS reaction increases.

关 键 词：WGS Pt(111) CO掺杂 DFT 反应机理 

分 类 号：TQ426[化学工程] O643.3[理学—物理化学]