Engineering Catalytic Microenvironment Enabling Direct Carbonate Electrolysis to Ethylene

The preparation of multicarbon products, such as ethylene (C2H4), is primarily achieved through gas-phase CO2 electrolysis. However, this method faces challenges, including low CO2 utilization and inefficient catalysts. To address these issues, direct carbonate electrolysis can be employed effectively. In this study, we propose a microenvironment-modulated strategy to enhance the efficiency of direct carbonate electrolysis to C2H4 using a Cu catalyst. By incorporating a hydrophobic component, polytetrafluoroethylene (PTFE), on the surface of the Cu catalyst, we achieved a significant improvement in C2H4 selectivity, from 1.07% for the Cu catalyst to 13.48% for the Cu/50% PTFE catalyst at 100 mA cm–2. Furthermore, by optimizing the CO coverage at the catalytic interface with tandem components, notably Ni–N–C, the Faradaic efficiency of C2H4 was boosted to 21.72% at the same current density. Notably, the CO2 gas was almost undetectable at the outlet during a long-term stability test, indicating nearly 100% CO2 utilization. This research underscores the significance of adjusting the catalyst microenvironment at the electrode–electrolyte interface for direct (bi)carbonate electrolysis.