Rare-Earth-Modified Magnesium Aluminate Spinel-Supported PtSn Nanoparticles for Propane Dehydrogenation

Propane dehydrogenation (PDH) is a crucial petrochemical process for propylene production, driven by the high demand for plastics and chemical feedstocks. Although alumina is a common industrial catalyst support, its acidic sites induce strong adsorption of dehydrogenated products (propylene), promoting undesirable cracking and coke formation. To address this issue, rare-earth-modified magnesium aluminate spinel (MAS) supports were synthesized via a urea-assisted hydrothermal method, and PtSn nanoparticles were then deposited on these supports as PDH catalysts. Compared with alumina, the rare-earth-modified MAS exhibited significantly reduced acidity and weakened propylene adsorption capacity, markedly inhibiting coke deposition. Furthermore, incorporating the rare-earth elements enhanced the interaction between the PtSn nanoparticles and the support (e.g., Sm-modified MAS). This stronger interaction promoted better PtSn nanoparticle dispersion, resulting in smaller average Pt cluster sizes, and improved resistance to sintering during both the PDH reaction and oxidation–reduction regeneration cycles. Consequently, the rare-earth-modified MAS-supported PtSn catalyst exhibited notable catalytic activity, long-term stability, and regeneration performance in PDH. Prepared using conventional wetness impregnation on a rare-earth-modified MAS support, this efficient catalyst offers good compatibility with existing industrial PtSn/alumina catalyst preparation protocols and is suitable for large-scale production, and exhibits significant practical prospects in the propane dehydrogenation process.