Electrocatalytic reduction reaction of carbon dioxide (CO₂RR) provides an attractive way to convert carbon dioxide (CO₂) to carbon monoxide (CO) from which more complex carbon-based fuels and feedstocks can be synthesized. As CO₂ is a thermodynamically stable molecule, tremendous efforts have been made in recent years to find suitable catalysts for electrocatalytic CO₂RR. It is recently reported that the electrocatalytic reduction reaction of carbon dioxide can be significantly enhanced by the use of a sharp-tip electrode. However, the experimentally observed rate enhancement is many orders of magnitudes smaller than what would be expected from an energetic point of view. Dr. Huijun Jiang, Prof. Zhonghuai Hou and Prof. Yi Luo in USTC proposed a novel reaction-diffusion kinetic model to resolve above mentioned mechanistic problem. The experimentally observed sharp-tip enhanced reaction and the maximal producing rate of carbon monoxide under different electrode potentials were well-reproduced. Remarkably, it was found that the optimal CO₂RR performance shows a strong dependence on the interaction between CO₂ and the local electric field, on the adsorption rate of CO₂, but not on the reaction barrier. Two new strategies to further enhance the reaction rate ware also proposed. The findings highlight the importance of kinetics in modeling electrocatalytic reactions.

http://onlinelibrary.wiley.com/wol1/doi/10.1002/anie.201708825/abstract