期刊
CARBON
卷 156, 期 -, 页码 389-398出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.carbon.2019.09.059
关键词
-
资金
- CONICYT-Chile [Fondecyt-1160949, PFB-27]
At the heart of the mechanism and efficiency of oxygen reduction is the identification of active sites in graphene-based electrocatalysts ranging from carbon blacks to heat-treated phthalocyanines. Distinction between the transfer of two or four electrons points to O-2 dissociation as the essential mechanistic clue; here we examine this issue by exploiting the analogy with carbon oxidation, where production of CO vs. CO2 has long been a crucial point. We compare our computational results with experimental evidence on the behavior of graphene as well as its N-, B- and transition-metal-doped counterparts. Electron transfer is revealed to occur readily through a carbene-type site upon oxygen surface rearrangement. Whether adsorbed O-2 dissociates depends on proton transfer occurring before or after the stabilization of a peroxy intermediate; this in turn depends on electron density distribution at and around the active site. A good correlation exists between spin density at the active site and O-2 adsorption energy. (C) 2019 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据