Bismuth oxide nanoflakes grown on defective microporous carbon endows high-efficient CO₂ reduction at ampere level

Carbon dioxide electroreduction is a green technology for artificial carbon sequestration, which is being delayed from industrialization due to the lack of efficient catalysts at high current conditions. Herein, the Bi₂O₃ nanoflakes were uniformly grown on a defective porous carbon (PC). This self-assembling Bi₂O₃/PC catalyst was applied to drive CO₂ electroreduction at 1.0 A, 1.5 A and 2.0 A while the Faradaic efficiency of formate reaches 91.50 %, 86.30 % and 84.22 %, respectively. Density functional theory calculations revealed the intrinsic defect of carbon is able to give electron to Bi through O bridge, which increased the electron aggregation of Bi and lowered the generation energy barrier of *OCHO intermediate. Additionally, the unique 3D network of staggered Bi₂O₃ enhances the CO₂ adsorption and favors the electron transportation. By integrating all above advantages into a solid electrolyte-type cell, we are able to produce pure formic acid in a rate of 15.48 mmol h^-1 at ampere current.