Creation of intrinsic defects on ZIF-8 particles to facilitate electrochemical reduction of CO 2 over Fe single-atom catalyst

The fabrication of various defects on the surface of metal single-atom catalysts can improve their electrochemical CO 2 reduction reaction (CO 2 RR) ability, and the current mainstream research focuses on the defect modification of heteroatom doping, while there are fewer studies on intrinsic defects on carbon substrates. Herein, a series of catalysts with both Fe-N 4 sites and intrinsic defects were synthesized on the ZIF-8 surface by pyrolytic etching at a suitable temperature under ammonia atmosphere. Electrochemical tests in an H-cell showed that the catalyst achieved CO Faradaic efficiency (FE CO ) of 96.9 % and CO partial current density (J CO ) of 9.088 mA cm - 2 at -0.6 V. Through further studies, we introduced a " 585 " ring structure to describe these intrinsic defects and found that these intrinsic defects on the carbon-based surface can act as active sites to promote CO 2 RR along with the Fe-N 4 sites. This work provides a reference for the study of intrinsic defect-modified single atomic materials.