Surface iodine and pyrenyl-graphdiyne co-modified Bi catalysts for highly efficient CO_(2) electroreduction in acidic electrolyte

CO_(2) electroreduction to formic acid/formate would contribute to alleviating the energy and climate crisis.This work reports a Bi-based catalyst derived from the in-situ electroreduction of Bi_(2)O_(2)CO_(3) modified with iodine and pyrenyl-graphdiyne(PGDY)on the surface for efficient electroreduction of CO_(2) in acidic electrolyte,with a high partial current density of 98.71 mA·cm^(-2) and high Faradaic efficiency(FE)>90%over the potential range from^(-1).2 to-1.5 V vs.reversible hydrogen electrode(RHE),as well as the long-term operational stability over 240 h without degradation in H-type cell.Experimental results and density function theory calculations show that the synergistic effect of surface iodine and PGDY is responsible for this active and extremely stable process of CO_(2) electroreduction via lowering the energy barriers for formation of*OCHO intermediate,suppressing the competitive HER by enhancing the concentration of both K+and CO_(2) at reaction interface,as well as preventing the dissolution and re-deposition of active Bi atoms on surface during catalytic reaction.This work provides new insight into designing highly active and stable electrocatalysts for CO_(2) reduction.