Metalloporphyrins and related metallomacrocycles as electrocatalysts for use in polymer electrolyte fuel cells and water electrolyzers

Metal complexes of N-4-macrocycles such as porphyrins and phthalocyanines have been studied for several decades as alternatives to Pt catalysts in polymer electrolyte fuel cells (PEFCs) and polymer electrolyte membrane (PEM) water electrolyzers. This review mainly describes the recent development of these catalysts for use in anode and cathode of PEFCs and PEM water electrolyzers. Performance of the developed catalysts and strategies of the development are summarized. This review aimed to discuss the advantages and disadvantages of the metallomacrocycle-based catalysts compared to conventional Pt electrocatalysts, and to emphasize their functions that the Pt catalyst does not have. (C) 2017 Elsevier B.V. All rights reserved.