Tackling the activity and selectivity challenges of electrocatalysts towards CO2 reduction reaction via atomically dispersed dual atom catalysts

Atomically dispersed catalysts are widely employed in electrochemical CO2 reduction reaction (CO2RR) owing to maximal atomic utilization and outstanding intrinsic activity. Dual atom catalysts (DACs) can provide dispersed active sites and distinct electronic structure, which is conducive to the catalytic performance. In this work, we explored a series of DACs composed of transition metals or main group metals supported on nitrogen-doped graphene (M2-NC) toward high-performance CO2RR. The radius of metal atom is a key factor determining the stability of M2-NC, that metals (M = Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Sn, Pt, and Bi) with small radius can be steadily anchored. Fe2/Co2/Ru2-NC are screened out to activate CO2 because of the strong interaction between metals d orbitals and CO2 2 pi orbitals. The results show that Fe2/Co2-NC can promote CO2RR to generate HCOOH with limiting potentials (UL) of -0.36 and -0.25 V. Ru2-NC can catalyze the generation of CH3OH and CH4 with UL of -0.28 V. Limited potential difference between CO2RR and hydrogen evolution reaction (HER) show that Fe2/Co2/Ru2-NC can inhibit HER during CO2RR. This work demonstrates Fe2/Co2/Ru2-NC as high-performance CO2RR catalysts and highlights the type of central metal atoms as a vital role for atomically dispersed electrocatalysts.