Hydrogenomics: Efficient and Selective Hydrogenation of Stable Molecules Utilizing Three Aspects of Hydrogen

Hydrogen is chemically flexible revealing three aspects; protium (H $$^0$$ ), proton (H $$^+$$ ), and hydride (H $$^-$$ ), which are active toward hydrogenation reactions. While the reactivity of protium is characterized by the potential energy at a catalyst surface, electron transfer is of importance as an additional degree of freedom in the reactions with proton and hydride. A promising strategy is to make full use of these active hydrogen species for hydrogenation of stable molecules and achieve chemical transformation of these molecules, which we call “Hydrogenomics”. By reviewing recent studies on the hydrogenation of hydrocarbon, carbon dioxide, dinitrogen, and so on using these active hydrogen species on model metal surfaces, nanoscale electrocatalysts, and multimetallic polyhydride clusters, we discuss the fundamental concepts behind the reactions and possible control of the efficient and selective hydrogenation reactions.