Nanoporous Metal-Organic Framework-Based Ellipsoidal Nanoparticles For The Catalytic Electroreduction Of Co2

Electroreduction of carbon dioxide (CO2) to carbon monoxide (CO) is a promising strategy to reduce the superfluous CO2 in the atmosphere while simultaneously generating renewable fuel and crucial raw materials for industrial manufacturing. Here, we report a hierarchical nanoporous catalyst with ellipsoidal morphology to achieve efficient CO production from CO2. By retaining the micropores of the metal-organic framework (MOF) precursor to enhance CO2 concentration in the gas-diffusion electrode (GDE) and fabricating mesopores during pyrolysis to assist mass transfer, the nanoporous catalyst delivers 200 mA cm(-2) current density at -0.30 V versus the reversible hydrogen electrode (RHE) and near-unity Faradaic efficiency toward CO (FECO) of 98.7% under ambient conditions. It also achieved 645 mA cm(-2) CO partial current density (j(CO)) at -0.53 V vs RHE with 86% FECO, allowing a turnover frequency (TOF) of 159 s(-1) normalized to electrochemically active surface area (ECSA). Electrocatalytic generation of CO and O-2 from CO2 and water was observed at a cell voltage of only 1.40 V, just slightly above the equilibrium voltage of 1.34 V. Furthermore, the nanoporous catalyst continually delivers CO at 100 mA cm(-2) at -0.6 V vs RHE for 8 h with FECO greater than 98%.