Modular O2 electroreduction activity in triphenylene-based metal–organic frameworks† †Electronic supplementary information (ESI) available: Materials and methods. CVs of the MOFs under N2. CVs of Cu3(HITP)2 deactivating. CVs of the trigonal MOFs on ITO. % current retained during potentiostatic ORR. RRDE data. Faradaic efficiencies. Koutecky–Levich data. ORR exchange current densities. ORR [O2] order data. pH-dependent redox activity of the hexagonal MOFs. Redox inactivity of the trigonal MOFs. S

Electrically conductive layered metal–organic frameworks, regardless of the metal or chelating atom identity, exhibit phase-dependent catalytic activity for O 2 electroreduction. Triphenylene ligands hexasubstituted with amino or phenol groups afford two phases of electrically conductive layered two-dimensional metal–organic frameworks upon reaction with various metals. Regardless of the identity of the metal or chelating atom, π-stacking within the MOF layers is essential to achieve high electrical conductivity, redox activity, and catalytic activity.