Researchers have successfully synthesized a trimetallic catalyst, Cu92Sb5Pd3, which shows remarkable catalytic performance in converting carbon dioxide to carbon monoxide with high selectivity and activity. By alloying copper with antimony and palladium single atoms, the electronic structure of the catalyst is finely tuned to enhance CO production and suppress the competing hydrogen evolution reaction.
The catalyst was synthesized using a unique co-reduction method in pure ethanol solution, eliminating the need for complexants and potential contaminants. Characterization techniques such as inductively coupled plasma atomic emission spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy confirmed the successful incorporation of Sb and Pd atoms into the Cu matrix.
Further analysis using extended X-ray absorption fine structure measurements revealed the coordination environment of the Sb and Pd atoms, indicating their dispersed single-atom nature in the alloy. Operando X-ray absorption spectroscopy studies showed the electronic interaction between the Cu matrix and the dopants under reaction conditions, revealing electron-deficient states in the Cu matrix.
The CO2 reduction performance of Cu92Sb5Pd3 was evaluated through electrochemical measurements, showing high selectivity towards CO production with minimal hydrogen evolution. The catalyst displayed stable and durable performance over long-term testing, outperforming noble metal catalysts in terms of selectivity and activity.
Theoretical simulations further supported the experimental findings, suggesting that the synergistic effects of Sb and Pd single atoms on the Cu base enhance the CO2 reduction performance. Overall, the study provides a promising design strategy for developing efficient and selective electrocatalysts for carbon dioxide conversion.
