Oxidase-inspired selective 2e/4e reduction of oxygen on electron-deficient Cu

Development of low-cost and efficient (electro)catalysts with tunable 2e/4e oxygen reduction reaction (ORR) selectivity toward energy conversion, biomimetic catalysis and biosensing has attracted growing interest. Herein, we reported that carbon nanohybrids with O- or N-coordinated Cu (Cu-OC or Cu-NC) showed the superior activity for 2e and 4e electrocatalytic ORR with the selectivities of 84.0% and 97.2%, respectively. Experimental evidences demonstrated that the strong electron-rich O-doped carbon in Cu-OC donated electrons to Cu2+, weakening the binding strength of H2O2 at Cu-O centers and facilitating the 2e ORR pathway for selective production of H2O2. However, the poor electron-donor ability of the N-doped carbon in Cu-NC made Cu-N sites more electron-deficient due to the reduced electron transfer from N-doped carbon to Cu2+, promoting 4e ORR by enhancing adsorption of O2 and the ORR intermediates. The high 4e ORR activity of Cu-NC rendered its potential for application in Zn-air battery and oxidase...