A Facile Approach to Alumina-Supported Pt Catalysts for the Dehydrogenation of Propane

The catalytic dehydrogenation of propane is an economically interesting process for the production of propylene due to its high selectivity to the olefin and the coupled generation of hydrogen. The catalysts are usually obtained by depositing the active components from solutions onto a support. Here we show that the direct synthesis of alumina-supported platinum catalysts in a ball mill in a single step provides easy access to efficient catalysts that are comparable in performance to materials obtained by more complex synthesis techniques. This was demonstrated by analysis using XRD, N₂ adsorption, chemical analysis, FTIR spectroscopy, and electron microscopy and by functional characterization of the catalysts in the dehydrogenation of propane to propylene. Although the ball milling procedure was not optimized, the catalysts exhibit a narrow Pt particle size distribution around 2 nm and are active at comparatively low reaction temperatures, producing in the steady state at 500 °C approximately 300 g_propylene g_Pt^-1 h^–1. The selectivity remains very high even at temperatures as high as 550 °C. Sintering of Pt under the harsh reaction conditions is not observed. The scalable method saves energy and avoids waste as no solvents and no thermal or reducing pretreatments are required.