Stabilizing the isolated Pt sites on PtGa/Al2O3 catalyst via silica coating layers for propane dehydrogenation at low temperature

Catalytic conversion of propane to propylene can be achieved by non-oxidative propane dehydrogenation (PDH) by Pt-based catalysts under 550–700 °C. In this work, we report a strategy to decrease the Pt loading amount to only 0.1 wt% for obtaining a stable catalyst via silica coating for high PDH activity at a temperature as low as of 450 °C. The as-prepared 2.5%Si@PtGa/Al2O3 catalyst shows outstanding catalytic activity (propylene productivity rate 0.5 mol/gcat.·h) close to its equilibrium conversion (24.5%) with much better stability (deactivation constant: 0.007 h−1) at 450 °C. The interface between catalyst and silica coating changes the strong metal-support interaction (SMSI) to immobilize the Ga oxide clusters, further tightly anchoring the Pt catalytic sites for PDH process. Moreover, the electronic state of Pt is also influenced by the silica coating layers. This work demonstrates a new method to harnessing the metal-support interaction in catalysis. [Display omitted] •The dehydrogenation of propane was studied over ultra-low Pt loading catalyst.•Ga is an efficient co-catalyst to obtain highly dispersed Pt sites.•Catalyst stability is significantly enhanced by coating silica layers for PDH at 450 °C.•The electronic structure of the active metals can be adjusted through the regulation of metal-support interface.