Hydrogen and oxygen evolution reactions catalyzed by transition metal carbonyls

Abstract This work reports the activity of the transition metal carbonyl complexes hexarhodium hexadecacarbonyl (Rh 6 (CO) 16 ), tetrairidium dodecacarbonyl (Ir 4 (CO) 12 ), triruthenium dodecacarbonyl (Ru 3 (CO) 12 ), triosmium dodecacarbonyl (Os 3 (CO) 12 ) and tungsten hexacarbonyl W(CO) 6 towards the hydrogen evolution reaction and the oxygen evolution reaction in an acid medium (0.5 mol L − 1 H 2 SO 4 ), measured by the rotating disk electrode technique with cyclic and linear sweep voltammetry, and up to 3000 consecutive measurements for each reaction. Rh 6 (CO) 6 displayed the best performance for the hydrogen evolution reaction, reaching an overpotential of 74.6 mV at a geometrical current density of 10 mA cm − 2 , while Ir 4 (CO) 12 exhibited an outstanding performance for the oxygen evolution reaction, achieving an overpotential of 207.3 mV at a geometrical current density of 10 mA cm − 2 . The results are indicative of the potential use of these materials as electrodes in water splitting devices that work under acidic conditions, such as polymer electrolyte membrane electrolyzers and acidic photoelectrochemical water splitting cells. Graphical abstract