Molecular cobalt electrocatalyst for proton reduction at low overpotential

Linear trimetallic Co(III)/Co(II)/Co(III) cobalt complexes with bridging acyl-alkoxy ligands are electrocatalysts for the reduction of tosic acid in acetonitrile. The -OCMe2CH2COMe complex appears to operate homogeneously, and at a modest onset overpotential of 175 mV. A turnover frequency of ca. 80 s(-1) was observed at an overpotential of 300 mV.