Deuteration mechanistic studies of hydrogenase mimics

Hydrogen production is key to carbon-free energy production and the use of hydrogenases is an excellent approach for this achievement since they produce hydrogen with extraordinary efficiencies. However, these enzymes have several shortcomings, which may be resolved using hydrogenase mimics. The design and synthesis of these mimics is a very active area of research, and the understanding of the mode of the action of mimics is particularly relevant to the future design of robust and productive catalysts. In this review, we discuss the role of isotopes (mainly deuterium) in disentangling key steps of the mechanisms of H2 activation by mimics of hydrogenases. Through selected examples, we focus on the key aspects of processes that, in many cases, have allowed a better understanding of the mode of action of the natural enzymes, making a valuable contribution to the design of more efficient complexes for the production of hydrogen.