Zhang Wuzhengzhi, Zhu Nannan, Ding Lianchun, Hu Yan, Wu Zhengcui
Anhui Laboratory of Molecule-Based Materials (State Key Laboratory Cultivation Base), The Key Laboratory of Functional Molecular Solids, Ministry of Education, Key Laboratory of Electrochemical Clean Energy of Anhui Higher Education Institutes, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, P. R. China.
Inorg Chem. 2021 Dec 20;60(24):19356-19364. doi: 10.1021/acs.inorgchem.1c03183. Epub 2021 Nov 29.
It is an ongoing pursuit for researchers to precisely control the catalyst's surface for high-performance CO electrochemical reduction (COER). In this work, CuO mesoporous nanosheets (CuO MNSs) with rough edges decorated by small Ag nanoparticles (Ag NPs) with a tunable amount of Ag were synthesized on a Cu foil at normal atmospheric temperature through two-step solution-phase reactions for COER to CO. In this special Ag NPs/CuO MNSs heterostructure, the mesoporous CuO NSs with rough edges favored gas infiltration, while decorated Ag NPs expanded the active sites for CO molecule adsorption. Ag NPs endowed Ag NPs/CuO MNSs with good electrical conductivity and promoted the adsorbed CO molecules to obtain electrons from the catalyst. Especially, the Ag-CuO interface stabilized the *COOH intermediate with strong bonding, which is important in boosting COER to CO. The optimal Ag/CuO can catalyze COER to CO with a Faradaic efficiency of 91.2% and a partial current density of 10.5 mA cm at -0.7 V. Moreover, it exhibited prominent catalytic stability, retaining 97.8% of the initial current density and 97.6% of the original Faradaic efficiency for CO after 12 h of testing at -0.7 V. Notably, the Faradaic efficiency of CO on Ag/CuO can retain over 80% in the potential area from -0.6 to -0.9 V, embodying its high selectivity for CO. This work develops precious metal/metal oxide heterostructures with a low precious metal loading for efficacious COER to CO and beyond.
精确控制催化剂表面以实现高性能的一氧化碳电化学还原（COER）是研究人员一直以来的追求。在这项工作中，通过两步溶液相反应在常温下于铜箔上合成了边缘粗糙且装饰有可调银含量的小银纳米颗粒（Ag NPs）的氧化铜介孔纳米片（CuO MNSs），用于将COER转化为CO。在这种特殊的Ag NPs/CuO MNSs异质结构中，边缘粗糙的介孔CuO NSs有利于气体渗透，而装饰的Ag NPs扩展了CO分子吸附的活性位点。Ag NPs赋予Ag NPs/CuO MNSs良好的导电性，并促进吸附的CO分子从催化剂获取电子。特别是，Ag-CuO界面通过强键稳定了*COOH中间体，这对于促进COER转化为CO很重要。最佳的Ag/CuO可以在-0.7 V下以91.2%的法拉第效率和10.5 mA cm的分电流密度催化COER转化为CO。此外，它表现出显著的催化稳定性，在-0.7 V下测试12小时后，保留了初始电流密度的97.8%和CO原始法拉第效率的97.6%。值得注意的是，Ag/CuO上CO的法拉第效率在-0.6至-0.9 V的电位区域内可以保持超过80%，体现了其对CO的高选择性。这项工作开发了具有低贵金属负载量的贵金属/金属氧化物异质结构，用于高效地将COER转化为CO及其他应用。
