Electro- and Photocatalytic Generation of H2 Using a Distinctive CoII “PN3P” Pincer Supported Complex with Water or Saturated Saline as a Hydrogen Source

Abstract

Efficient electrocatalytic production of H2 from mixed water/acetonitrile solutions was achieved using three new CoII complexes supported by the neutral pincer ligand bis(diphenylphosphino)-2,6-di(methylamino)pyridine (“PN3P”). At −1.9 V vs. Fc/Fc+, these catalysts showed 96 % Faradaic efficiency with added water or saturated aqueous saline at rates of up to 316 L(mol cat)−1(cm2)−1 h−1 using a glassy carbon working electrode. The complex [Co(κ3-2,6-{Ph2PNMe}2(NC5H3)Br2] (1) was also able to photocatalytically reduce water to hydrogen in the presence of a Ru(bpy)32+ photosensitizer and a reductant.