Cobalt Schiff-base complexes for electrocatalytic hydrogen generationElectronic supplementary information (ESI) available. CCDC 1549635 and 1549636. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7dt01750b

Two cobalt( iii ) complexes containing inexpensive Schiff-base ligands have been found to be active for proton reduction at low overpotentials. The dinitro and tetranitro derivatized Schiff-base complexes show catalytic activity at −0.96 V and −1.1 V vs. Fc + /Fc, respectively, resulting in overpotentials of 120 mV and 280 mV. Foot-of-the-wave analysis is used to examine the kinetic properties of these complexes, yielding a theoretical TOF max of up to 4100 s −1 . Experimental TOFs of 7 s −1 and 3 s −1 are observed. Catalytic Tafel plots are also presented in order to benchmark the relationship between turnover frequency and overpotential. Two cobalt( iii ) complexes containing inexpensive Schiff-base ligands have been found to be active for proton reduction at low overpotentials.