镍钴双金属化合物作为高效的硫氧化催化剂并辅助超低能耗电化学制氢

Nickel-cobalt bimetallic compounds as efficient catalysts for sulfion oxidation reaction to produce hydrogen with ultralow energy consumption

本工作通过简便快捷的电沉积法在泡沫镍基底上超快速制备镍钴双金属化合物(Ni-Co@NF)作为高效的硫离子氧化反应(Sulfion oxidation reaction,SOR)催化剂。并将基于Ni-Co@NF催化的SOR反应代替电化学析氧半反应(Oxygen evolution reaction,OER)与析氢反应(Hydrogen evolution reaction,HER)耦合,成功构建新型低能耗耦合制氢反应体系。通过分析催化材料的X射线衍射谱图、扫描电镜图片和X射线光电子能谱图可知:镍钴双金属呈纳米片状结构成功负载在泡沫镍基底上。随后Ni-Co@NF的SOR性能测试显示其具有较高的SOR本征活性,仅需要0.347V vs.RHE的超低电势即获得100mA·cm^(-2)的电流密度。除此之外,Ni-Co@NF催化材料不仅具有最低的Tafel斜率(77m V·dec^(-1))和最小的电化学阻抗,还拥有良好的催化稳定性。以上结果均证实Ni-Co@NF具有优异的SOR电催化性能。同时,我们在实际电化学制氢的双电极系统中对比了阳极SOR和OER的电势,进一步证明了使用SOR代替OER可以有效降低整体电化学制氢的能耗。

In this work,Nickel-cobalt bimetallic compounds as efficient catalysts for sulfion oxidation reaction(SOR)are rapidly prepared on a foamed nickel substrate by a simple and fast electrodeposition method.The SOR catalyzed by Ni-Co@NF is used to replace the electrochemical oxygen evolution reaction(OER)and coupled with the hydrogen evolution reaction(HER)to successfully construct a novel hydrogen production reaction system with ultra-low energy consumption.The results of the X-ray diffraction spectrum,the scanning electron microscopy images and X-ray photoelectron spectrogram of Ni-Co@NF show that the nano flake nickelcobalt bimetallic compounds are successfully loaded on the foam nickel substrate.The SOR catalytic performance test demonstrates that the Ni-Co@NF displays high intrinsic activity and only needs a very low potential of 0.347 V vs.RHE to attain the current density of 100 mA·cm^(-2)Besides,Ni-Co@NF owns the lowest Tafel slope(77 mV·dec^(-1)),the smallest electrochemical impedance and good stability.The above results all confirm that the Ni-Co@NF possesses the efficient electrocatalytic performance for SOR.Meanwhile,we compare the reaction potential of SOR and OER in the two-electrode system for actual electrochemical hydrogen production.This result further indicates that using the SOR to substitute the OER can eficiently decrease the energy consumption of the electrochemical hydrogen production.