Zhu Jiawei, Chen Zitao, Xie Minghao, Lyu Zhiheng, Chi Miaofang, Mavrikakis Manos, Jin Wanqin, Xia Younan
The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, Jiangsu, 211816, China.
Angew Chem Int Ed Engl. 2019 May 27;58(22):7244-7248. doi: 10.1002/anie.201901732. Epub 2019 Mar 26.
We report a highly active and durable water oxidation electrocatalyst based on cubic nanocages with a composition of Ir Pd , together with well-defined {100} facets and porous walls of roughly 1.1 nm in thickness. Such nanocages substantially outperform all the water oxidation electrocatalysts reported in literature, with an overpotential of only 226 mV for reaching 10 mA cm at a loading of Ir as low as 12.5 μg cm on the electrode in acidic media. When benchmarked against a commercial Ir/C electrocatalyst at 250 mV of overpotential, such a nanocage-based catalyst not only shows enhancements (18.1- and 26.2-fold, respectively) in terms of mass (1.99 A mg ) and specific (3.93 mA cm ) activities, but also greatly enhanced durability. The enhancements can be attributed to a combination of multiple merits, including a high utilization efficiency of Ir atoms and an open structure beneficial to the electrochemical oxidation of Ir to the active form of IrO .
我们报道了一种基于立方纳米笼的高活性且耐用的析氧电催化剂，其组成为铱钯，具有明确的{100}晶面以及厚度约为1.1 nm的多孔壁。这种纳米笼在析氧电催化剂方面的性能显著优于文献中报道的所有同类催化剂，在酸性介质中，当电极上铱的负载量低至12.5 μg cm 时，达到10 mA cm 的过电位仅为226 mV。当与商业铱碳（Ir/C）电催化剂在250 mV过电位下进行对比时，这种基于纳米笼的催化剂不仅在质量活性（1.99 A mg ）和比活性（3.93 mA cm ）方面分别提高了18.1倍和26.2倍，而且耐久性也大大增强。这些增强可归因于多种优点的结合，包括铱原子的高利用效率以及有利于将铱电化学氧化为活性形式IrO 的开放结构。
