Remote p-d Orbital Hybridization via First/Second-layer Coordination of Fe Single Atoms with Heteroatoms for Enhanced Electrochemical CO2-to-CO Reduction

d–p orbital hybridization induced by S/N in the coordination layer of pyrrole-type Fe–N 4 can modulate the electronic structure of Fe single atoms, enabling *COOH adsorption and *CO desorption to exclusively furnish CO but suppressing H 2 formation.