A water soluble electro-catalyst for generating hydrogen based on a cobalt(III) complex supported by 1,10-phenanthroline

•Reaction of 1,10-phenanthroline (phen), Co(NO3)2·6H2O and tetracyanoethylene affords a complex, [(phen)3Co(CN)2]·NO3 1.•1 can electrocatalyze hydrogen evolution both from acetic acid and aqueous buffer.•This provides a method for water reduction catalysis using coordinatively saturated complexes in purely aqueous media.