Surface reconstruction via dissolution-reprecipitation of commercial alumina support to improve propane dehydrogenation performance
Abstract
Precise control of porous alumina microstructures is always challenging due to the complexity and diversity of alumina crystalline phases and surface properties. In this study, we developed a universal top-down synthetic approach to construct a novel alumina layer on the surface of commercial alumina through a diffusion-dominated dissolution-reprecipitation process. During the reconstruction, the original nanoparticles transformed into a layer of rod-like structured alumina, resulting in a 58% reduction in total acidity and a sevenfold increase in the coordinatively unsaturated pentacoordinate aluminum sites (Al3+ penta). Such kind of alumina-supported PtSn catalyst exhibited significantly improved reactivity in propane dehydrogenation, with propane conversion increasing from an initial 36.6% to 42.7% and the deactivation rate reducing from 0.028 h-1 to 0.011 h-1 at 590 ℃ with a WHSV of 9.4 h-1. These results demonstrated the feasibility of surface reconstruction on commercial alumina and provided essential insights for the development of industrial catalysts.
