Zhou Xianlong, Shan Jieqiong, Chen Ling, Xia Bao Yu, Ling Tao, Duan Jingjing, Jiao Yan, Zheng Yao, Qiao Shi-Zhang
School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA 5005, Australia.
Key Laboratory of Material Chemistry for Energy Conversion and Storage (Ministry of Education), Hubei Key Laboratory of Material Chemistry and Service Failure, Wuhan, National Laboratory for Optoelectronics, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan 430074, China.
J Am Chem Soc. 2022 Feb 9;144(5):2079-2084. doi: 10.1021/jacs.1c12212. Epub 2022 Jan 28.
Copper is the only metal catalyst that can perform the electrocatalytic CO reduction reaction (CRR) to produce hydrocarbons and oxygenates. Its surface oxidation state determines the reaction pathway to various products. However, under the cathodic potential of CRR conditions, the chemical composition of most Cu-based catalysts inevitably undergoes electroreduction from Cu to Cu or Cu species, which is generally coupled with phase reconstruction and the formation of new active sites. Since the initial Cu active sites are hard to retain, there have been few studies about Cu catalysts for CRR. Herein we propose a solid-solution strategy to stabilize Cu ions by incorporating them into a CeO matrix, which works as a self-sacrificing ingredient to protect Cu active species. In situ spectroscopic characterization and density functional theory calculations reveal that compared with the conventionally derived Cu catalysts with Cu or Cu active sites, the Cu species in the solid solution (Cu-Ce-O) can significantly strengthen adsorption of the *CO intermediate, facilitating its further hydrogenation to produce CH instead of dimerization to give C products. As a result, different from most of the other Cu-based catalysts, Cu-Ce-O delivered a high Faradaic efficiency of 67.8% for CH and a low value of 3.6% for CH.
铜是唯一能够进行电催化CO还原反应（CRR）以生成碳氢化合物和含氧化合物的金属催化剂。其表面氧化态决定了生成各种产物的反应途径。然而，在CRR条件下的阴极电势下，大多数铜基催化剂的化学组成不可避免地会经历从Cu到Cu或Cu物种的电还原过程，这通常伴随着相重构和新活性位点的形成。由于初始的Cu活性位点难以保留，关于用于CRR的铜催化剂的研究很少。在此，我们提出一种固溶体策略，通过将Cu离子掺入CeO基体中来稳定Cu离子，CeO基体作为一种自我牺牲成分来保护Cu活性物种。原位光谱表征和密度泛函理论计算表明，与具有Cu或Cu活性位点的传统衍生铜催化剂相比，固溶体（Cu-Ce-O）中的Cu物种能够显著增强*CO中间体的吸附，促进其进一步氢化生成CH而不是二聚生成C产物。结果，与大多数其他铜基催化剂不同，Cu-Ce-O对CH的法拉第效率高达67.8%，对CH的法拉第效率低至3.6%。
