摘要
利用水合肼氧化反应(HzOR)取代缓慢的析氧反应(OER)是一种可以在海水裂解中长期产生氢气并抑制不利的析氯反应(ClER)的方法.然而,很少有催化剂能够满足在双电极系统中同时呈现出优异的析氢反应(HER)和HzOR以达到较低的电池电压的要求.在此,我们报道了双金属Ni_(4)Mo/Ni_(4)W纳米合金作为双功能催化剂,该催化剂对HER(-7 mV,10 mA cm^(-2))和HzOR(-16 mV,10 mA cm^(-2))具有显著的催化活性.在1.0 mol L^(-1)KOH/2.0 molL^(-1)NaCl/0.1 mol L^(-1)N_(2)H_(4)电解液中,双电极系统需要34,295和548 mV的低电池电压就能达到10,100和200mAcm^(-2).密度泛函理论计算表明,Ni-Mo/W耦合不仅可以降低水解离的自由能和氢的吸附/脱附,而且可以优化吸附水合肼中间体的脱氢动力学.
Replacing sluggish oxygen evolution reaction(OER)by hydrazine oxidation reaction(HzOR)is a promising way to produce hydrogen and suppress unfavorable chlorine evolution reaction(ClER)in long-term seawater splitting.However,few catalysts can meet the demand to process outstanding hydrogen evolution reaction(HER)and HzOR simultaneously to achieve relatively low cell voltage in a twoelectrode system.Herein,we report bimetallic Ni_(4)Mo/Ni_(4)W nanoalloys as bifunctional catalysts with remarkable catalytic activity towards both HER(-7 mV at 10 mA cm^(-2))and HzOR(-16 mV at 10 mA cm^(-2)).Surprisingly,low cell voltages of 34,295 and 548 mV are required to achieve 10,100 and 200 mA cm^(-2) in a two-electrode system with ideal stability in 1.0 mol L^(-1) KOH/2.0 mol L^(-1) NaCl/0.1 mol L^(-1) N_(2)H_(4) electrolyte.Density functional theory calculations disclose that the Ni-Mo/W coupling can not only reduce the free energy of water dissociation as well as hydrogen adsorption/desorption,but also optimize the dehydrogenation kinetics of adsorbed intermediates.
作者
王珂宇
梁晨
易致远
徐放
王一兴
雷林峰
庄林洲
徐至
Keyu Wang;Chen Liang;Zhiyuan Yi;Fang Xu;Yixing Wang;Linfeng Lei;Linzhou Zhuang;Zhi Xu(State Key Laboratory of Chemical Engineering,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)
基金
supported by the National Key R&D Program of China(2021YFB3801301)
the National Natural Science Foundation of China(22075076,22005098 and 22208092)。
