Manipulating dehydrogenation kinetics through dual-doping Co3N electrode enables highly efficient hydrazine oxidation assisting self-powered H2 production

• Published in: Nature communications Vol. 11; no. 1; pp. 1853 - 13
• Main Authors: Liu, Yi, Zhang, Jihua, Li, Yapeng, Qian, Qizhu, Li, Ziyun, Zhu, Yin, Zhang, Genqiang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 15.04.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/299; 639/638/77/886; 639/925/357; Catalysis; Catalysts; Catalytic activity; Dehydrogenation; Doping; Electric potential; Electric power; Electrodes; Electronic devices; Energy efficiency; Evolution; Fuel cells; Humanities and Social Sciences; Hydrazine; Hydrazines; Hydrogen evolution reactions; Hydrogen production; Kinetics; multidisciplinary; Nanotechnology; Nanowires; Oxidation; Oxygen evolution reactions; Reaction kinetics; Room temperature; Science; Science (multidisciplinary); Splitting; Voltage; Water splitting
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-15563-8

Replacing sluggish oxygen evolution reaction (OER) with hydrazine oxidation reaction (HzOR) to produce hydrogen has been considered as a more energy-efficient strategy than water splitting. However, the relatively high cell voltage in two-electrode system and the required external electric power hinder its scalable applications, especially in mobile devices. Herein, we report a bifunctional P, W co-doped Co 3 N nanowire array electrode with remarkable catalytic activity towards both HzOR (−55 mV at 10 mA cm −2 ) and hydrogen evolution reaction (HER, −41 mV at 10 mA cm −2 ). Inspiringly, a record low cell voltage of 28 mV is required to achieve 10 mA cm −2 in two-electrode system. DFT calculations decipher that the doping optimized H* adsorption/desorption and dehydrogenation kinetics could be the underlying mechanism. Importantly, a self-powered H 2 production system by integrating a direct hydrazine fuel cell with a hydrazine splitting electrolyzer can achieve a decent rate of 1.25 mmol h −1 at room temperature. While facile hydrazine oxidation could replace the sluggish H 2 O oxidation reaction in renewable H 2 production, few bifunctional catalysts exist. Here, authors explore a dual-doping strategy for Co 3 N nanowires that bestows bifunctionality toward both hydrazine oxidation and H 2 evolution catalysis.