Electrochemistry of and Electrocatalysis by Low-Symmetry N 4 Macrocycles

The introduction of efficient and affordable catalysts for three seemingly simple electrochemical reactions could improve very much the sustainability of our energy supply: reduction of protons to hydrogen gas (the hydrogen evolution reaction, HER), water oxidation, and selective reduction of oxygen to water (the oxygen reduction reaction, ORR). 1–6 Platinum group metals (PGM) are outstanding catalysts for all these reactions, but being rare and expensive prevents their utility for large scale operations. 7 Within the search for catalysts based on earth abundant 1 st row transition metals, we now introduce two different molecular catalysts: Co(III) complexes of corroles, with very different in size meso -C substituents (C 6 F 5 >> CF 3 >> H), as well by newly synthesized and fully characterized Co(II), Cu(II) and Ni(II) monoazaporphyrins (MAzP) with meso -CF 3 substituents. All the catalyst were adsorbed on carbon supports with very different porosity (Vulcan