Tailoring of single copper atoms anchored on N, P co-doped carbon for electrochemical CO2 reduction

The electrochemical CO₂ reduction reaction (CO₂RR) is a promising strategy to convert the greenhouse gas CO₂ into valuable products using electricity as a feedstock. This study presents the development of single-atom copper catalyst anchored on a nitrogen and phosphorus co-doped carbon matrix designed for CO₂RR. The impact of carbonization temperature on the structural properties of the electrocatalysts, such as porosity and the electronic environment, was systematically examined, revealing its influence on the selectivity towards C₁ and C₂₊ products. Increased microporosity was associated with an enhanced hydrogen evolution reaction (HER), whereas mesoporosity contributed to improved CO₂ reduction reaction activity. Aberration-corrected transmission electron microscope evidenced that P addition improved the dispersion of Cu, whether in the form of single atoms or clusters. Moreover, phosphorus doping suppressed HER and promoted the formation of products such as methane, ethylene, and ethanol. The coexistence of Cu⁺, Cu⁰, and copper single atoms was identified as key to facilitating C-C bond formation. This study emphasizes the critical balance between textural and electronic properties in optimizing catalytic performance and provides valuable insights for designing advanced electrocatalysts for CO₂ valorization.