Liu Dongmei, Xu Hui, Wang Cheng, Shang Hongyuan, Yu Rui, Wang Yuan, Li Jie, Li Xingchi, Du Yukou
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Renai Road, Suzhou 215123, P. R. China.
Inorg Chem. 2021 Apr 19;60(8):5882-5889. doi: 10.1021/acs.inorgchem.1c00295. Epub 2021 Apr 2.
Developing high-performance and cost-efficient catalysts toward oxygen evolution reaction (OER) is an important but daunting task due to the sluggish kinetics hindered by the four-electron transfer process. Herein, an advanced class of ultralow Ru-doped NiCo-MOF hollow porous nanospheres (denoted as Ru@NiCo-MOF HPNs) has been reported in this work. Benefiting from the high porosity and large surface area of the metal-organic frameworks (MOFs) and optimized electronic properties by Ru doping, the as-prepared Ru@NiCo-MOF HPNs exhibit superior performance for water oxidation with the overpotential of only 284 mV to reach a current density of 10 mA·cm in alkaline electrolyte, as well as a small Tafel slope of 78.8 mV·dec, outperforming the NiCo-MOF HPNs (358 mV) and commercial RuO catalyst (326 mV). The incorporation of Ru in NiCo-MOF HPNs enables a stable OER activity for at least 39 h. Moreover, we have probed the interaction between the content of Ru and OER performance, impressively, Ru@NiCo-MOF HPNs with 13.5 atom % Ru doping (denoted as Ru@NiCo-MOF-4) exhibited the highest OER activity with the excellent mass activity of 310 mA·mg at an overpotential of 284 mV. Besides, a two-electrode cell with Ru@NiCo-MOF-4 as the anode and commercial Pt/C catalyst as the cathode also demonstrated outstanding electrocatalytic overall water splitting performance with a cell potential of merely 1.57 V to deliver a current density of 10 mA·cm.
由于四电子转移过程阻碍了动力学，开发用于析氧反应（OER）的高性能且经济高效的催化剂是一项重要但艰巨的任务。在此，本文报道了一类先进的超低Ru掺杂NiCo-MOF中空多孔纳米球（记为Ru@NiCo-MOF HPNs）。受益于金属有机框架（MOFs）的高孔隙率和大表面积以及Ru掺杂优化的电子性质，所制备的Ru@NiCo-MOF HPNs在碱性电解质中表现出优异的析氧性能，过电位仅为284 mV时即可达到10 mA·cm的电流密度，以及78.8 mV·dec的小塔菲尔斜率，优于NiCo-MOF HPNs（358 mV）和商业RuO催化剂（326 mV）。在NiCo-MOF HPNs中掺入Ru可实现至少39小时的稳定析氧活性。此外，我们探究了Ru含量与析氧性能之间的相互作用，令人印象深刻的是，Ru掺杂量为13.5原子%的Ru@NiCo-MOF HPNs（记为Ru@NiCo-MOF-4）在284 mV的过电位下表现出最高的析氧活性，质量活性高达310 mA·mg。此外，以Ru@NiCo-MOF-4作为阳极和商业Pt/C催化剂作为阴极的双电极电池也展示出出色的电催化全水解性能，电池电位仅为1.57 V时即可提供10 mA·cm的电流密度。
