Cu complexes that catalyze the oxygen reduction reaction

The oxygen reduction reaction (ORR) is employed in a large number of systems such as fuel cells and air batteries. Currently, the catalyst with the lowest overpotential for the ORR is the enzyme laccase. Laccase only functions at a very narrow pH range, and its large size prevents high current densities. Using copper based catalysts to mimic the ORR activity is an area with many spectroscopic results, but relatively few electrochemical studies. This review catalogs the various copper based ORR catalysts and their activities.

► Mulitcopper oxidases are some of the most efficient oxygen reduction catalysts.
► Coordination chemistry mimics of these enzymes feature nitrogenous ligands.
► Carbon supported Cu complexes of both diamino triazole and tris pyridyl amine are effective ORR catalyst.
► ORR efficacy of Cu complexes in base is better than in acid.