Water-splitting electrocatalytic properties and computational characterization of a symmetrically substituted porphyrazine

The porphyrazine 2,7,12,17-tetra-tert-butyl-5,10,15,20-tetraaza- 21H,23H-porphine was studied regarding its electrocatalytic water-splitting activity in a wide pH range. Two different methods were employed to manufacture electrodes based on this compound: a solution-based method and a catalyst ink- -based one. The most catalytically active electrode was obtained using the catalyst ink-based method. In 1 mol L-1 KOH solution it displays an H2 evolution reaction overpotential of 0.6 V and a Tafel slope of 0.15 V dec-1. Statistical analysis revealed a significant correlation between the pH and the O2 evolution reaction overpotential. Quantum chemical calculations were performed to obtain a more detailed understanding of the porphyrazine?s properties.