A study group headed by Profs. Xinhe Bao, Guoxiong Wang, and Dunfeng Gao from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has suggested a new strategy for energy- and carbon-efficient acidic CO2 electrolysis.
Using customized catalyst microenvironments, researchers achieved acidic CO2 electrolysis to CO with high energy efficiency and high CO2 utilization efficiency at current industrial densities.
At 500 mA cm-2, they achieved CO Faradaic efficiency as maximum as 95% in optimal reaction conditions, and the equivalent total cell energy efficiency was 39%. Compared with alkaline electrolysis, the CO2 loss was decreased by 86%, and the single-pass CO2 utilization efficiency was as high as 85%.
Furthermore, they have shown that the co-existence of K+ and H+ played a significant role in stabilizing the initial *CO2 intermediate, which leads to increased CO formation with theoretical calculation findings.
They also arranged an acid/alkaline tandem CO2 electrolysis system, establishing carbon-efficient CO2 conversion to multicarbon products (C2+) through a CO2-CO-C2+ route.
“This work provides new insights into tuning catalyst microenvironments for carbon-efficient CO2 electrolysis towards practical application,” concluded Prof. Wang.
Journal Reference:
Li, H., et al. (2023). Tailoring acidic microenvironments for carbon-efficient CO2 electrolysis over a Ni–N–C catalyst in a membrane electrode assembly electrolyzer. Energy & Environmental Science. doi.org/10.1039/d2ee03482d.