Tuning the local coordination environment of silver(I) coordination networks with counterions for enhanced electrocatalytic CO2 reduction

This study is led by Prof. Yujie Xiong (Anhui Normal University) and Prof. Tingting Kong (Anhui Normal University). Since the local coordination environment of the active site has a great influence on its performance in electrocatalytic CO₂ reduction by adjusting the intrinsic kinetics of CO₂ activation and intermediate stabilization, it is imperative to elucidate the mechanism of this influence in order to rationally design highly efficient catalysts; however, due to the complex interactions between the multiple factors involved in the system, it is challenging to establish a well-defined structure-performance relation challenging.

Recently, Prof. Yujie Xiong, Prof. Tingting Kong, and Prof. Xiaofeng Cui reported two examples of iso-structural ion-intercalated silver(I)-based coordination networks (AgCNs) with well-defined structures and investigated the effect of different intercalated ions on the electrocatalytic CO₂ reduction performance. The experimental results show that AgCNs-BF₄ has better CO₂ electroreduction performance than AgCNs-ClO₄. AgCNs-BF₄ achieves the highest Faraday efficiency of CO₂ to CO conversion (87.1%) at −1.0 V (vs. RHE) with a higher partial current density, whereas AgCNs-ClO₄ is only 77.2% at the same applied potential. Spectroscopic characterizations and theoretical calculation show that the presence of BF₄^- is more favorable for stabilizing the COOH* intermediate by weakening the hydrogen bonds, which accounts for the higher activity of AgCNs-BF₄.