Polymers with intrinsic microporosity (PIMs) for targeted CO2 reduction to ethylene

Abstract

CO₂ reduction offers an attractive alternative green synthetic route for ethylene, especially where CO₂ could be sourced from industrial exhausts and in combination with green power sources. However, practical applications are currently limited due to the unfortunately low selectivity of cathode materials towards ethylene. This work uses polymers with intrinsic microporosity (PIMs) to improve the performance of copper gas diffusion electrodes for CO₂ reduction to ethylene. We report an improved selectivity and activity towards ethylene with the addition of a thin PIMs layer, which is seen as improved Faradaic efficiency, increased stability and a shift in the reduction to lower overpotential. This improvement is highly dependent on the thickness of the added polymer layer, with too thick a layer having a detrimental impact on the hydrophobicity of the gas diffusion layer. With a compromise in loading, PIMs can be used to enhance the activity and selectivity of catalysts for targeted CO₂ reduction to ethylene.

Keywords: Carbon dioxide; Electrochemistry; Ethylene; Gas diffusion electrode; Polymers with intrinsic microporosity; Triphasic interface.