Porous Co 3 Mo 3 N can act as a multifunctional electrocatalyst for OER, ORR, and HER -Co 3 Mo 3 N performs better than precious metal catalysts -Cobalt oxide-rich activation surface layer is shown to aid OER activity -Better ORR and HER performance of Co 3 Mo 3 N is due to Co and Mo d-states ll www.cell.com/the-innovation