摘要
This study demonstrates that embedding sub-nanometer Bi oxide atomic clusters onto Cu-based nanoparticles enables precise control over product selectivity in the electrocatalytic CO2 reduction reaction (ECR) through synergistic oxygen vacancy (OV) engineering. At 1.0 at.% Bi loading, Bi clusters generate a high density of surrounding OVs. These OVs act as dynamic OH− reservoirs during water dissociation, promoting the regeneration of active Cu sites for CO2 activation and significantly enhancing CH4 yield and selectivity (up to 42 %). Increasing the Bi loading to 2.0 wt% maintains sub- nm clusters while incorporating metallic Bi atoms into the Cu surface. This metallic Bi further accelerates water dissociation, elevating surface OH− concentration and shifting selectivity toward formic acid. A combination of characterization reveals a localized synergistic mechanism: Bi clusters and their associated OVs stabilize adsorbed oxygen species (Oads) from CO2 dissociation and facilitate water activation, while simultaneously regenerating adjacent metallic Cu active sites. This cooperative interaction, underpinned by strong sub-nanometer confinement effects, not only tailors product distribution (CH4 vs. HCOOH) but also drastically improves catalyst durability. The findings provide essential theoretical insights and practical pathways for designing efficient Cu-based nanocatalysts via atomic cluster engineering and vacancy control for enhanced ECR performance.
•Incorporation of sub-nanometer Bi cluster boosts the CO2 electrochemical reduction to CH4 performance of Cu2O nanoparticle.•This material delivers the CH4 selectivity of ∼42 % at 1.2 V vs. RHE.•It shows a degradation less than 5.0 % in the stability test up to 7 h.