题 目：Octahedral gold-silver nanoframes with rich crystalline defects for efficient methanol oxidation manifesting a CO-promoting effect
作 者：Likun Xiong1,2, Zhongti Sun1,2, Xiang Zhang1,2, Liang Zhao 1,2, Peng Huang1,2, Xiwen Chen1,2, Huidong Jin1,2,Hao Sun1,2, Yuebin Lian1,2, Zhao Deng 1,2, Mark H. Rümmerli1,2, Wanjian Yin1,2, Duo Zhang3,4,
Shuao Wang3,4 & Yang Peng 1,2
单 位：1 Soochow Institute for Energy and Materials Innovations, College of Energy, Soochow University, Suzhou 215006, P. R. China.
2 Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Suzhou, P. R. China.
3 State Key Laboratory of Radiation Medicine and Protection,School of Radiation Medicine and Protection,Soochow University, Suzhou 215123, P. R. China.
4 Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou, P. R. China.
Three-dimensional bimetallic nanoframes with high spatial diffusivity and surface heterogeneity possess remarkable catalytic activities owing to their highly exposed active surfaces and tunable electronic structure. Here we report a general one-pot strategy to prepare ultrathin octahedral Au3Ag nanoframes, with the formation mechanism explicitly elucidated through well-monitored temporal nanostructure evolution. Rich crystalline defects lead to lowered atomic coordination and varied electronic states of the metal atoms as evidenced by extensive structural characterizations. When used for electrocatalytic methanol oxidation, the Au3Ag nanoframes demonstrate superior performance with a high specific activity of 3.38 mA cm?2, 3.9 times that of the commercial Pt/C. More intriguingly, the kinetics of methanol oxidation on the Au3Ag nanoframes is counter-intuitively promoted by carbon monoxide. The enhancement is ascribed to the altered reaction pathway and enhanced OH?co-adsorption on the defect-rich surfaces, which can be well understood from the d-band model and comprehensive density functional theory simulations.