标题: Electro-synthesis of tungsten carbide containing catalysts in molten salt for efficiently electrolytic hydrogen generation assisted by urea oxidation
作者: Fan, JH (Fan, Jinhang); Dou, YP (Dou, Yanpeng); Jiang, R (Jiang, Rui); Du, KF (Du, Kaifa); Deng, BW (Deng, Bowen); Wang, DH (Wang, Dihua)
来源出版物: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 卷: 46 期: 28 页: 14932-14943 DOI: 10.1016/j.ijhydene.2020.07.193 出版年: APR 21 2021
摘要: Energy-efficient production of hydrogen through urea electrolysis is still challenging due to the lack of satisfactory catalysts for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) in urea containing solution. In this study, Ni-WxC/C (x = 1,2) composite with high activity for urea electrocatalysis was prepared by direct electro-reduction of affordable feedstock of NiO-CaWO4-C in molten CaCl2-NaCl at 873-973 K. The addition of graphite in precursor decreases the particle size of Ni. Introducing WxC into Ni particles can reduce the overpotential for UOR. As a result, the obtained Ni-WxC/graphite composite exhibits high current density for urea oxidation, which is about 11-folds and 52-folds higher than that of Ni/graphite and Ni (@1.53 V vs. RHE), respectively. After changing the carbon source from graphite to CNTs, the anodic current density was further increased by 43%, reaching 50.31 mA cm(-2). Moreover, the cathodic catalyst WxC/CNTs obtained by the same preparation process exhibits high performance towards HER, with a low onset potential of 131.5 mV and a Tafel slope of 69.5 mV dec(-1). Assembling an electrolyzer using Ni-WxC/CNTs as anode and WxC/CNTs as cathode can yield a current density of 10 mA cm(-2) at merely 1.65 V in 1 M KOH/0.33 M urea aqueous solution, with excellent long-term electrochemical durability. The environmental-friendly production process uses affordable feedstocks for the synthesis of efficient catalysts toward urea electrolysis, promising an energy-saving hydrogen production as well as waste treatment. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
作者关键词: Hydrogen evolution reaction; Molten salt electrolysis; Ni-WxC/C; Urea oxidation reaction
地址: [Fan, Jinhang; Dou, Yanpeng; Jiang, Rui; Du, Kaifa; Deng, Bowen; Wang, Dihua] Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430072, Peoples R China.
通讯作者地址: Wang, DH (通讯作者)，Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430072, Peoples R China.
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