Enhanced PtIn Catalyst via Ce-Assisted Confinement Effect in Propane Dehydrogenation

Abstract

The PtIn nanoalloys with high surface energy are generally in a metastable state during harsh reaction conditions, and the ordered alloy structure is not conducive to exposure of surface Pt active sites. Herein, a strategy for restructuring the unfavorable PtIn alloy structure via heteroatom (Ce) doping is applied to advance an isolated Ptδ+ confined by the InCeO x nanoislands supported on SiO2. The as-synthesized catalyst with optimizing PtIn(Ce) ternary components exhibits ∼92.2% selectivity toward propylene and a stable propane conversion of ∼67.1% at 550 °C (k d of 0.010 h–1). As demonstrated by the comprehensive characterizations, the introduced proper amount of Ce species leads to the reorganization of the disadvantaged PtIn nanoalloy structure into the robustness of the isolated Ptδ+ site confined by the InCeO x nanoislands via inhibiting the In0 species generation. The introduced Ce species modulate the electronic interaction between Pt, In, and carrier, stimulating the capability to activate reactive molecules and at the same time acting as spatial physical barriers to restrict the migration of the isolated Ptδ+ species. This work proposed a facile and efficient strategy to promote the capability against sintering and coking of the Pt-based catalyst in propane dehydrogenation.