Pt–ZnO<sub><i>x</i></sub> Interfacial\nEffect on the Performance of Propane Dehydrogenation and Mechanism\nStudy

Bimetallic Pt-based catalysts, for example, PtZn and\nPtSn catalysts,\nhave gained significant attention for addressing the poor stability\nand low selectivity of pristine Pt catalysts over propane dehydrogenation\n(PDH). However, the structures of the active sites and the corresponding\ncatalytic mechanism of PDH are still elusive. Here, we demonstrate\na spatially confined Pt–Zn<i><sub>m</sub></i>O<sub><i>x</i></sub>@RUB-15 catalyst (where “<i>m</i>” is the mole ratio of Zn/Pt and RUB-15 is a layered silica),\nwhich exhibited high catalytic activity, ultrahigh selectivity (>99%),\nand resistance to coking at 550 °C for PDH. Significantly different\nfrom the preliminary studies over the PtZn catalysts, through the\nassistance of quasi-<i>in situ</i> X-ray photoelectron spectroscopy\n(XPS), <i>in situ</i> Fourier transform infrared spectroscopy\n(CO-FTIR), <i>in situ</i> X-ray absorption spectroscopy\n(XAS), and CO titration, we discovered that the active sites for PDH\nwere the Pt–ZnO<sub><i>x</i></sub> interfaces, characterized\nby a structure of Pt<sup>δ+</sup>–Zn<sup>2+</sup>–O–Si.\nDensity functional theory (DFT) calculations showed that Pt atoms\npositioned at Pt–ZnO<sub><i>x</i></sub> interfaces\nwith coordinatively unsaturated ZnO<sub><i>x</i></sub> sites\nfacilitate the C–H bond breaking of propane while concurrently\nsuppressing deep dehydrogenation processes. This study suggests that\nengineering the interfaces of Pt–metal oxides under spatially\nconfined conditions holds promise for developing highly efficient\nPt-based catalysts for light alkane dehydrogenation.