Surface Water as an Initial Proton Source for the Electrochemical CO Reduction Reaction on Copper Surfaces

Autor: Feng Shao, Zhaoming Xia, Futian You, Jun Kit Wong, Qi Hang Low, Hai Xiao, Boon Siang Yeo
Rok vydání: 2022
Předmět:
Zdroj: Angewandte Chemie (International ed. in English).
ISSN: 1521-3773
Popis: Herein, we used in situ electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) and density functional theory (DFT) calculations to study the CO reduction reaction (CORR) on Cu single-crystal surfaces under various conditions. Coadsorbed and structure-/potential-dependent surface species, including *CO, Cu-Oad, and Cu-OHad, were identified using electrochemical spectroscopy and isotope labeling. The relative abundance of *OH follows a 'volcano' trend with applied potentials in aqueous solutions, which is yet absent in absolute alcoholic solutions. Combined with DFT calculations, we propose that the surface H2O can serve as a strong proton donor for the first protonation step in both the C1 and C2 pathways of CORR at various applied potentials in alkaline electrolytes, leaving adsorbed *OH on the surface. This work provides fresh insights into the initial protonation steps and identity of key interfacial intermediates formed during CORR on Cu surfaces.
Databáze: OpenAIRE