H 2 and O 2 Activation—A Remarkable Insight into Hydrogenase

This article summarizes the development of a range of organometallic, biomimetic analogues of [NiFe]hydrogenases and their employment in a new generation of H 2 ‐ O 2 fuel cells. It begins with a summary of O 2 ‐sensitive and O 2 ‐tolerant enzyme chemistry before detailing the properties and functionality of our biomimetic complexes, including: the first ever fully functional model, selective H 2 and O 2 activation, and the first catalyst using only common metals. These systems are centered on Ni–Fe, Ni–Ru, Ir–Ir, and Rh–Rh cores and use a range of ligands that all follow a set of design principles described herein.