Efficient electrocatalytic reduction of CO 2 to CO enhanced by the synergistic effect of N,P on carbon aerogel.

A metal-free catalyst, N,P-codoped carbon aerogel, was used to realize the high efficiency reduction of CO 2 to CO. Therein, the pyridinic N acts as the active center to activate and reduce CO 2 and the atom of P acts as the "transition atom" of the proton to reduce the free energy barrier from *CO 2 to *COOH.