Year: 2026
Type: preprint
Abstract: CO2 electrosorption at metal electrodes is a critical step controlling the subsequent electrochemical reduction process, yet its physicochemical origin remains debated. The field-induced stabilization of adsorbed CO2 – the field effect − is commonly attributed to the interaction between the applied electric field and the adsorption-induced molecular dipole of CO2 . In this study, we employ density functional theory with an applied electric field to re-examine this paradigm by studying CO2 electrosorption on (111) surfaces of Ag, Au, Cu, Ir, Pb, and Pt. We show an electric-field-driven transition between physisorbed and chemisorbed CO2 . Physisorption preserves a near-linear geometry with negligible charge transfer and weak field dependence, whereas chemisorption involves pronounced bending and substantial electron transfer from the metal. Collectively, we demonstrate that the field effect arises from the interaction between the electric field and the interfacial metal–CO2 dipole formed upon charge transfer, rather than the molecular CO2 dipole alone, as conventionally assumed.
Source: ChemRxiv
Institutions: University of Latvia, University of Tartu
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7213893557