Effect of Boron Promotion on Coke Formation during Propane Dehydrogenation over Pt/γ-Al2O3 Catalysts

The effect of boron promotion on the performance of 3 wt % Pt/γ-Al2O3 catalysts during propane dehydrogenation was investigated. A series of boron-promoted Pt/XB-γ-Al2O3 catalysts were synthesized, tested, and characterized. The sequential impregnation of 1 wt % boron and 3 wt % platinum decreases the amount of deposited carbon 3-fold, increases the propylene selectivity from 90% to 98%, and enhances the activity after 12 h by 40%. Catalyst characterization and thermodynamic DFT calculations suggest that boron forms a finely dispersed amorphous oxide on the γ-Al2O3 support and on the platinum particles, modifying both the selectivity of the metal sites and the strength and number of acid sites on the support.