Combined effects of sea urchin-like structure and mixed Cu+/Cu0 states on promoting C2 formation in electrocatalytic CO2 reduction

• Published in: Frontiers of chemical science and engineering 2024-03, Vol.18 (3), Article 30
• Main Authors: Shan, Mengqing, Lu, Dongsheng, Dong, Jiatong, Yan, Shen, Han, Jinyu, Wang, Hua
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Catalysis for a sustainable future; Chemical reduction; Chemistry; Chemistry and Materials Science; Copper oxides; Efficiency; Electrocatalysts; Electron transfer; Industrial Chemistry/Chemical Engineering; Nanotechnology; Oxidation; Raman spectra; Research Article; Synergistic effect
• ISSN: 2095-0179; 2095-0187
• DOI: 10.1007/s11705-024-2393-5

Surface engineering and Cu valence regulation are essential factors in improving the C 2 selectivity during the electrochemical reduction of CO 2 . Herein, we present a sea urchin-like CuO/Cu 2 O catalyst derived from rhombic dodecahedra Cu 2 O through one-step oxidation/etching method where the mixed Cu + /Cu 0 states are formed via in situ reduction during electrocatalysis. The combined effects of the morphology and the mixed Cu + /Cu 0 states on C–C coupling are evaluated by the Faradaic efficiency of C 2 and the C 2 /C 1 ratio obtained in an H-cell. R-CuO/Cu 2 O exhibited 49.5% Faradaic efficiency of C 2 with a C 2 /C 1 ratio of 3.1 at −1.4 V vs. reversible hydrogen electrode, which are 1.5 and 3.2 times higher than those of R-Cu 2 O, respectively. Using a flow-cell, 68.0% Faradaic efficiency of C 2 is achieved at a current density of 500 mA·cm −2 . The formation of the mixed Cu + /Cu 0 states was confirmed by in situ Raman spectra. Additionally, the sea urchin-like structure provides more active sites and enables faster electron transfer. As a result, the excellent C 2 production on R-CuO/Cu 2 O is primarily attributed to the synergistic effects of the sea urchin-like structure and the stable mixed Cu + /Cu 0 states. Therefore, this work presents an integrated strategy for developing Cu-based electrocatalysts for C 2 production through electrochemical CO 2 reduction.