Efficient hydrogen production on MoNi4 electrocatalysts with fast water dissociation kinetics

• Published in: Nature communications Vol. 8; no. 1; pp. 15437 - 8
• Main Authors: Zhang, Jian, Wang, Tao, Liu, Pan, Liao, Zhongquan, Liu, Shaohua, Zhuang, Xiaodong, Chen, Mingwei, Zschech, Ehrenfried, Feng, Xinliang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.05.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 639/301/299/886; 639/638/675; 639/638/77/886; Chemical Sciences; Electrolytes; Energy; Humanities and Social Sciences; Hydrogen; Hydrogen production; Kinetics; multidisciplinary; Nickel; or physical chemistry; Platinum; Science; Science (multidisciplinary); Theoretical and; Japan; Germany
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms15437

Various platinum-free electrocatalysts have been explored for hydrogen evolution reaction in acidic solutions. However, in economical water-alkali electrolysers, sluggish water dissociation kinetics (Volmer step) on platinum-free electrocatalysts results in poor hydrogen-production activities. Here we report a MoNi 4 electrocatalyst supported by MoO 2 cuboids on nickel foam (MoNi 4 /MoO 2 @Ni), which is constructed by controlling the outward diffusion of nickel atoms on annealing precursor NiMoO 4 cuboids on nickel foam. Experimental and theoretical results confirm that a rapid Tafel-step-decided hydrogen evolution proceeds on MoNi 4 electrocatalyst. As a result, the MoNi 4 electrocatalyst exhibits zero onset overpotential, an overpotential of 15 mV at 10 mA cm −2 and a low Tafel slope of 30 mV per decade in 1 M potassium hydroxide electrolyte, which are comparable to the results for platinum and superior to those for state-of-the-art platinum-free electrocatalysts. Benefiting from its scalable preparation and stability, the MoNi 4 electrocatalyst is promising for practical water-alkali electrolysers. In water-alkali electrolyzers, sluggish water dissociation kinetics on platinum-free electrocatalysts result in poor hydrogen-production activities. Here the authors report a MoNi 4 electrocatalyst which reduces the kinetic energy barrier of water dissociation, leading to improved hydrogen-production performance.