Cai Weizheng, Chen Rong, Yang Hongbin, Tao Hua Bing, Wang Hsin-Yi, Gao Jiajian, Liu Wei, Liu Song, Hung Sung-Fu, Liu Bin
School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore.
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China.
Nano Lett. 2020 Jun 10;20(6):4278-4285. doi: 10.1021/acs.nanolett.0c00840. Epub 2020 May 13.
Catalytic water splitting driven by renewable electricity offers a promising strategy to produce molecular hydrogen, but its efficiency is severely restricted by the sluggish kinetics of the anodic water oxidation reaction. Amorphous catalysts are reported to show better activities of water oxidation than their crystalline counterparts, but little is known about the underlying origin, which retards the development of high-performance amorphous oxygen evolution reaction catalysts. Herein, on the basis of cyclic voltammetry, electrochemical impedance spectroscopy, isotope labeling, and in situ X-ray absorption spectroscopy studies, we demonstrate that an amorphous catalyst can be electrochemically activated to expose active sites in the bulk thanks to the short-range order of the amorphous structure, which greatly increases the number of active sites and thus improves the electrocatalytic activity of the amorphous catalyst in water oxidation.
由可再生电力驱动的催化水分解为生产分子氢提供了一种很有前景的策略，但其效率受到阳极水氧化反应缓慢动力学的严重限制。据报道，非晶态催化剂在水氧化方面表现出比其晶态对应物更好的活性，但对于其潜在原因知之甚少，这阻碍了高性能非晶态析氧反应催化剂的开发。在此，基于循环伏安法、电化学阻抗谱、同位素标记和原位X射线吸收光谱研究，我们证明，由于非晶态结构的短程有序性，非晶态催化剂可以被电化学激活以暴露出本体中的活性位点，这大大增加了活性位点的数量，从而提高了非晶态催化剂在水氧化中的电催化活性。
