Nanoconfined Molecular Catalysts in Integrated Gas Diffusion Electrodes for High-Current-Density CO2 Electroreduction

Molecular catalysts are promising catalysts to electrochemically convert CO2 into CO with high selectivity. However, achieving industrial-level current density remains challenging due to the limitation of charge- and mass-transport in gas diffusion electrode. Herein, a novel gas diffusion electrode architecture by confining highly dispersed cobalt(II) phthalocyanine (CoPc) molecules into -graphene oxide (GO) nanosheets (denoted as CoPc@GO) is designed. Benefiting from the accelerated CO2 diffusion and charge transport in the nanoconfined structure, the designed electrode achieves a high CO partial current density of 481.65 +/- 12.50 mA cm(-2) and a cathode energy efficiency over 64% for CO. The experimentally measured CO2 transport dynamics and molecular dynamics simulation confirm the accelerated CO2 diffusion, while theoretical calculations reveal the decreased energy barrier of the CO2 activation in the confined space. This study paves a new way for electrode architecture design that would accelerate the implementation of CO2 electrolysis technology.