Mixed-valence Co0/IIOx clusters on silicalite-1 facilitate propane dehydrogenation to propene

Understanding the nature of active sites in heterogeneous catalysts and how to create them purposefully opens up the possibility of tailored catalyst design. Here we report mixed-valence subnanometre CoOx clusters, consisting of a few metallic Co0 atoms on top of Co2+, bound to a silicalite-1 support through lattice oxygen atoms as active species for non-oxidative propane dehydrogenation (PDH) to propene. Compared with commercial-like PtSn/Al2O3 and K-CrOx/Al2O3 catalysts also tested in the present study, as well as other state-of-the-art Pt- or Co-containing PDH catalysts, this system showed high on-stream stability, propene productivity and selectivity at close-to-equilibrium propane conversion. Moreover, it showed durability in a series of PDH/regeneration cycles between 500 and 550 °C. The performance of this catalyst system is industrially attractive in terms of propene production costs, as suggested by our initial techno-economic assessment. Cobalt-based catalysts are regarded as a potentially cheaper alternative to platinum and chromium systems for the non-oxidative dehydrogenation of propane, although they often feature lower performance. Now mixed-valence Co0/IIOx clusters supported on silicalite-1 are identified as a competitive system for this reaction.