Effect of preparation method on the Pt-In modified Mg(Al)O catalysts over dehydrogenation of propane

The Pt-In modified Mg(Al)O catalysts were prepared by co-precipitation, co-impregnation, and successive impregnation methods with Pt and In loading at 0.3 and 0.6 wt.%, respectively. The catalysts were tested in the propane dehydrogenation at 550 degrees C and atmospheric pressure. Pt loading on In-modified Mg(Al)O support prepared by co-precipitation (Pt/Mg(In)(Al)O) exhibited the highest catalytic performances with initial propane conversion and propylene selectivity of 24.2%.and 98.2%, respectively. As revealed by the H-2-TPR and XPS results, the Pt/Mg(In)(Al)O exhibited a stronger metal-support interaction and favorable led to more PtIn alloy formation compared to those obtained by the other methods, which greatly enhanced the catalytic performance and stability. Coke formation was significant reduced on all the prepared bimetallic PtIn catalysts, especially coke on the active metal, which diminished the catalytic deactivation. The catalysts were also characterized by CO chemisorption, transmission electron microscopy (TEM), NH3-temperature program desorption (NH3-TPD).