Trends in selective hydrogenation

Abstract

In spite of being commercialized for well over a century, hydrogenation is still a subject of intensive research and development. A patent landscape analysis showed high growth rates for topics related to climate change, bio-renewables, low waste and recyclability. The current paper describes trends, providing examples on the effect of structure sensitivity, on novel intermetallic active phases and on discoveries initiated by modelling. Due to increased processing costs and a negative environmental impact of undesirable by-products, the present focus favours high selectivity over activity. A relatively new class of materials showing an exponential growth in publications, these are the so-called intermetallics. These materials are defined as compounds formed by at least two metals, with – at least partly – ordered crystal structures which are different from the ones of the constituting elements. Non-metallic active phases formed by interaction of a metal ion and a (reducible) support may have a superior hydrogenation performance compared to the corresponding zero-valent metals. Aided by Density Functional Theory modelling (DFT) new, often intermetallic catalysts like Ni5Ga3 were identified which sparked a great number of follow-up studies.