Xiong Likun, Sun Zhongti, Zhang Xiang, Zhao Liang, Huang Peng, Chen Xiwen, Jin Huidong, Sun Hao, Lian Yuebin, Deng Zhao, Rümmerli Mark H, Yin Wanjian, Zhang Duo, Wang Shuao, Peng Yang
Soochow Institute for Energy and Materials Innovations, College of Energy, Soochow University, Suzhou, 215006, P. R. China.
Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Suzhou, P. R. China.
Nat Commun. 2019 Aug 22;10(1):3782. doi: 10.1038/s41467-019-11766-w.
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 AuAg 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 AuAg nanoframes demonstrate superior performance with a high specific activity of 3.38 mA cm, 3.9 times that of the commercial Pt/C. More intriguingly, the kinetics of methanol oxidation on the AuAg 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.
具有高空间扩散率和表面异质性的三维双金属纳米框架，由于其高度暴露的活性表面和可调节的电子结构而具有显著的催化活性。在此，我们报告了一种通用的一锅法策略来制备超薄八面体金银纳米框架，并通过对时间纳米结构演变的良好监测明确阐明了其形成机制。大量的结构表征表明，丰富的晶体缺陷导致金属原子的原子配位降低和电子态变化。当用于电催化甲醇氧化时，金银纳米框架表现出优异的性能，比活性高达3.38 mA cm，是商业Pt/C的3.9倍。更有趣的是，一氧化碳反直觉地促进了金银纳米框架上甲醇氧化的动力学。这种增强归因于反应途径的改变和富缺陷表面上OH共吸附的增强，这可以从d带模型和综合密度泛函理论模拟中得到很好的理解。
