Modulating intramolecular electron and proton transfer kinetics for promoting carbon dioxide conversion.

A novel pentagon-heptagon paired azulene group that possesses a large dipole moment is immobilized onto a porphyrin. The as-prepared azulene iron porphyrin exhibits a narrower bandgap and higher electrocatalytic CO reduction activity than the pristine iron porphyrin. The maximum CO faradaic efficiency reaches 99.9%, which is the state-of-the-art value among molecular catalysts.