Interstitial carbon induces enriched Cuδ+ sites in Cu2O nanoparticles to facilitate CO2 electroreduction to C2+ products
Haoran Wang, Rongbo Sun, Peigen Liu, Haohui Hu, Chen Ling, Xiao Han, Yixiang Shi, Xusheng Zheng, Geng Wu, Xun Hong
Abstract
The electrochemical CO 2 reduction reaction (CO 2 RR) holds significant promise in advancing carbon neutrality. Developing catalysts for the electrochemical CO 2 RR to multi-carbon (C 2+ ) products (e.g., C 2 H 4 ) under industrial-level current density is urgently needed and pivotal. Herein, we report the Cu 2 O nanoparticles doped with interstitial carbon atoms (denoted as C-Cu 2 O NPs) for the conversion of CO 2 to C 2+ products. The interstitial carbon promotes the C-Cu 2 O NPs to possess abundant unsaturated Cu–O bonds, leading to a high-density Cu δ + (0 < δ <1) species. The obtained C-Cu 2 O NPs exhibited significant Faradic efficiency (FE) of C 2+ products approaching 76.9% and a partial current density reaching 615.2 mA·cm −2 under an industrial-level current density of 800 mA·cm −2 . Furthermore, the efficient electrosynthesis of C 2 H 4 achieved an FE of 57.4% with a partial current density of 459.2 mA·cm −2 . In situ electrochemical attenuated total reflection Fourier transform infrared spectroscopy and in situ Raman spectroscopy analyses revealed that C-Cu 2 O NPs stabilized the intermediate *CO and facilitated C–C coupling, leading to increased selectivity towards C 2+ products.