期刊
ACS CATALYSIS
卷 8, 期 1, 页码 673-677出版社
AMER CHEMICAL SOC
DOI: 10.1021/acscatal.7b03864
关键词
surface density; Mn valence state; manganese ferrite; oxygen reduction reaction; nanoparticles
资金
- Singapore Ministry of Education [RG3/17, MOE2015-T2-1-020]
- Singapore National Research Foundation under Campus for Research Excellence and Technological Enterprise (CREATE) programme
- Callahan Faculty Endowment fund from Oregon State University
The bulk chemistry has been successfully used as a descriptor for oxygen reduction reaction (ORR) activities of various metal oxides. However, as the size of oxides becomes small, the bulk chemistry may not be sufficient to describe the activities. Here, we report a systematic study on Mn-substituted ferrite MnxFe3-xO4 (x = 0.5-2.5) nano particles and the roles of surface Mn in determining their ORR activities. Gradual Mn substitution induced changes in Mn valence and crystal structure. However, there is no remarkable correlation that can be found between their bulk chemistry and ORR activities. Instead, the surface Mn density and valency were found to play dominant roles in determining the ORR. This work shows that, at a small particle size, the bulk chemistry of oxides may not be the descriptor for their electrochemical properties. Due to the significantly high surface/bulk ratio, the surface chemistry has to be carefully characterized to interpret the activities of oxide nanoparticles.
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