The performances and structure evolution processes of Pt-based catalysts for selective hydrogen combustion under propene-rich conditions

Selective hydrogen combustion (SHC) is a potential technology to improve the energy efficiency and per-pass conversion of light alkane dehydrogenation processes. Exploring SHC catalysts with high selectivity and stability are essential for successful process integration. In the present study, the kinetic behaviour and active sites evolution processes of Pt-based catalysts were investigated. It was found that highly selective hydrogen combustion could be achieved over Sn modified Pt-based catalysts in presence of both propane and propene (over 98%). The stability tests, kinetic study and catalyst’s structure characterization revealed that the existence of oxygenated species was the reason for accelerated coking reactions. The formation of graphitized cokes serving as additional unselective active sites and the oxidation of tin in PtSn alloy phases were identified as main factors leading to catalytic selectivity loss during long-run tests under propene-rich condition.