Hydrogenation of naphthalene to decalin catalyzed by Pt supported on WO3 of different crystallinity at low temperature

Two tungsten oxides (WO3-500 and WO3-900) were prepared at different calcination temperatures by using ammonium mettungstate as tungsten source. The physicochemical properties of WO3 before and after Pt loading were systematically characterized by XRD, SEM, TEM, XPS, H2-TPR, and NH3-TPD. The influence of the crystallization degree of WO3 on the hydrogenation of naphthalene was studied under low-temperature reaction conditions. Compared with the WO3-900 support, WO3-500 obtained by calcination at lower temperature exhibited a lower crystallization degree with a large amount of W5+ species, which resulted in strong interactions with Pt. The strong interaction between W species and Pt contributed to the high acidic strength. The Pt/WO3-500 catalyst demonstrated excellent catalytic performance for naphthalene hydrogenation to decalin at low reaction temperature (70°C) with full conversion and 100% decalin selectivity. Under identical conditions, conversion and decalin selectivity were only 26.7% and 1.7% over the Pt/WO3-900 catalyst. Combining the characteristics of the catalysts and their catalytic results, we revealed the promoting role of oxygen defects in WO3-supported Pt catalysts in the hydrogenation of naphthalene to decalin, which will provide theoretical guidance for designing efficient WO3-supported Pt catalysts for hydrogenation reactions.