Jia Mingwen, Choi Changhyeok, Wu Tai-Sing, Ma Chen, Kang Peng, Tao Hengcong, Fan Qun, Hong Song, Liu Shizhen, Soo Yun-Liang, Jung Yousung, Qiu Jieshan, Sun Zhenyu
State Key Laboratory of Organic-Inorganic Composites , College of Chemical Engineering , Beijing University of Chemical Technology , Beijing 100029 , P. R. China . Email:
Graduate School of EEWS , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea . Email:
Chem Sci. 2018 Nov 6;9(47):8775-8780. doi: 10.1039/c8sc03732a. eCollection 2018 Dec 21.
The development of highly selective, low cost, and energy-efficient electrocatalysts is crucial for CO electrocatalysis to mitigate energy shortages and to lower the global carbon footprint. Herein, we first report that carbon-coated Ni nanoparticles supported on N-doped carbon enable efficient electroreduction of CO to CO. In contrast to most previously reported Ni metal catalysts that resulted in severe hydrogen evolution during CO conversion, the Ni particle catalyst here presents an unprecedented CO faradaic efficiency of approximately 94% at an overpotential of 0.59 V, even comparable to that of the best single Ni sites. The catalyst also affords a high CO partial current density and a large CO turnover frequency, reaching 22.7 mA cm and 697 h at -1.1 V ( the reversible hydrogen electrode), respectively. Experiments combined with density functional theory calculations showed that the carbon layer coated on Ni and N-dopants in carbon material both play important roles in improving catalytic activity for electrochemical CO reduction to CO by stabilizing *COOH without affecting the easy *CO desorption ability of the catalyst.
开发高选择性、低成本且节能的电催化剂对于CO电催化以缓解能源短缺和降低全球碳足迹至关重要。在此，我们首次报道负载在N掺杂碳上的碳包覆Ni纳米颗粒能够实现CO高效电还原为CO。与大多数先前报道的在CO转化过程中导致严重析氢的Ni金属催化剂不同，此处的Ni颗粒催化剂在0.59 V的过电位下呈现出约94%的前所未有的CO法拉第效率，甚至与最佳的单Ni位点相当。该催化剂还具有高的CO分电流密度和大的CO周转频率，在 -1.1 V（可逆氢电极）下分别达到22.7 mA cm和697 h。实验与密度泛函理论计算相结合表明，包覆在Ni上的碳层和碳材料中的N掺杂剂在通过稳定COOH来提高电化学CO还原为CO的催化活性方面都起着重要作用，而不影响催化剂的CO容易脱附的能力。
