Two-dimensional porphyrin covalent organic frameworks with tunable catalytic active sites for the oxygen reduction reaction.

Four novel two-dimensional porphyrin COFs (M-TP-COF, M = H2, Co, Ni and Mn) with donor-acceptor dyads were fabricated and served as electrocatalysts for the oxygen reduction reaction (ORR). The ORR catalytic activity of M-TP-COF was tuned by changing the M atom in the center of the porphyrin backbone. The experimental structure-function relationship was in accordance with the results of density functional theory calculations based on the O2-O2*-OOH*-O*-OH*-OH- route.