Copper/Cobalt-Loaded Carbon Nanostructures as Catalysts for Electrochemical CO 2 Reduction

作者：Zhaoxing Wu, Zhengxiong Wu, Yulai Zhao, Linxi Hou · 发表于：ACS Applied Nano Materials · 年份：2024 · DOI：10.1021/acsanm.4c00869 · 被引用次数：12 · 研究领域：CO2 Reduction Techniques and Catalysts、Ionic liquids properties and applications、Electrocatalysts for Energy Conversion

The electrochemical reduction of CO 2 to produce high-value multicarbon products represents a challenging yet highly desirable process, particularly due to the inefficient C–C coupling observed in current electrocatalysts. In this study, Cu 2+ and Co 2+ were introduced into ZIF-8 as precursors to synthesize a series of Co- and CuCo-doped carbon nanostructure materials with varying Co-to-Cu ratios. X-ray diffraction and X-ray photoelectron spectroscopy (XPS) analyses confirmed the successful doping of metal Co in the form of Co–N x, while Cu was partly doped as nanoparticles attached to the carbon substrate surface and partly as single atoms forming Cu–N x . Transmission electron microscopy and energy-dispersive X-ray spectroscopy analyses revealed uniform distribution of elemental Co and Cu on the carbon substrate, with Cu loaded as nanocluster on the surface. Linear sweep voltammetry tests indicated that Cu/CoCu-N x -C composites exhibited enhanced reactivity toward CO 2 reduction compared to other samples. At −0.19 V (vs RHE), the Faradaic efficiencies (FEs %) of C 2 H 4, C 2 H 6, CH 4, CO, and H 2 over Cu/CoCu-N x -C were 29.7, 8.6, 20.2, 9.8, and 31.5%, respectively. The influence of Co and Cu doping modes on the selectivity of electrocatalytic reduction products was investigated. Results showed that Cu/CoCu-N x -C exhibited a higher FE of C 2 compared to Cu/Cu–N x -C, with nearly 10 times higher C 2 current density. Mechanistic insights from acid-etching experiments and ...