Atomically dispersed Pt in ordered PtSnZn intermetallic with Pt−Sn and Pt−Zn pairs for selective propane dehydrogenation

With the surge of shale gas, propane dehydrogenation becomes increasingly important to synthesize propylene. Herein, a new type of ordered PtSnZn intermetallic clusters (∼0.9 nm) supported on Al 2 O 3 was synthesized by a stepwise approach including electrostatic adsorption and temperature-programmed reduction. The structure of the PtSnZn clusters results from a kinetically controlled process, and Pt atoms in the PtSnZn clusters are well isolated by Sn and Zn with Pt−Sn and Pt−Zn pairs. The PtSnZn/Al 2 O 3 catalyst exhibits excellent catalytic performance for propane dehydrogenation, which achieves ∼100% propylene selectivity and keeps a high propane conversion (>40%) during stability testing. The catalytic performance of PtSnZn/Al 2 O 3 is also significantly higher than that of Pt/Al 2 O 3 , PtSn/Al 2 O 3 , and PtZn/Al 2 O 3 . Experiments and theoretical calculations indicate that the Sn 5p and Zn 4s orbitals are hybridized with Pt 5d by forming Pt−Sn and Pt−Zn pairs, which leads to the d band center of Pt deviating from Fermi level (−2.81 eV). The shift of the Pt d band center significantly decreases the adsorption energy of propylene and prohibits further dehydrogenation, resulting in high propylene selectivity and stability.