Efficient water oxidation catalyzed by homogeneous cationic cobalt porphyrins with critical roles for the buffer base

Significance Efficient and scalable catalysts that mediate the interconversion of electrical and chemical energy are essential to the future world economy. Central to this challenge are robust systems that can split water into its elements, hydrogen and oxygen, with minimal cost. In this article, we describe the discovery and characterization of an efficient, single-site homogeneous water oxidation catalyst based on a cationic cobalt-porphyrin system. Important roles of the buffer base in this catalysis are also described. Our results shed light on the design of next-generation water oxidation catalysts using earth-abundant transition metals and redox active ligand systems.