Mesoporous Silica SBA-15 Supported Pt-Ga Nanoalloys as an Active and Stable Catalyst for Propane Dehydrogenation

Propane dehydrogenation is one of the most admired technologies for propylene production. However, the development of an active and stable catalyst presents a significant challenge. In this study, Pt-Ga/SBA-15 catalysts were prepared via coimpregnation, followed by H-2 reduction, and applied in propane dehydrogenation. The Pt-Ga/SBA-15 catalyst with a Ga/Pt molar ratio of 1 exhibited a high propane conversion of up to 60% and high selectivity toward propylene of 98.2% at 550 degrees C for 10 min, with a propane conversion of 51.6% and propylene selectivity of 99.5% after reaction for 25 h. The physicochemical properties characterized using N-2 physisorption, XRD, TEM, XPS, CO chemisorption, and in situ CO-DRIFT spectroscopy reveal that the Pt-Ga alloy nanoparticles were formed on the SBA-15 support after direct reduction with H-2. The study of coke formation via temperature-programmed oxidation showed that a large amount of coke was deposited over the support of spent Pt-Ga/SBA-15 catalyst, indicating coke mobility from the active sites to the supports and its contribution to catalyst stability. The activities of spent catalysts could be almost completely recovered via reduction regeneration, during which Pt-Ga alloy retains the original geometrical and electronic structure well. The dilution of Pt ensembles due to the addition of Ga, e.g., Pt-Ga alloy formation, plays an important role in enhancing the catalytic performance for propane dehydrogenation.

Automated summary

In this study, Pt-Ga/SBA-15 catalysts were prepared and showed high activity and stability for propane dehydrogenation. The formation of Pt-Ga alloy played an important role in enhancing the catalytic performance.