Synthesis, characterization, and sulfur tolerance of Pt-MoOxcatalysts prepared from Pt-Mo alloy precursors

Novel Pt-MoΟ x catalytic systems were prepared by the oxidation-reduction of Pt-Mo alloy precursors with different metal contents. According to XRD, SEM, and TEM data, oxidation at 550 °C led to the destruction of initial alloys and the formation of molybdenum oxide and metallic platinum particles. As evidenced by TPR H 2 , adsorption measurements, and in situ XRD analysis, during reduction in the presence of Pt, molybdenum oxide can trap hydrogen already at ambient temperature with the formation of molybdenum oxide hydroxide or molybdenum bronzes. In contrast to initial alloys, the oxidized systems showed significant catalytic activity in toluene hydrogenation. The results suggested that both metallic platinum and molybdenum oxide contribute to this activity. The sulfur resistance test revealed that Pt-MoO x systems had an enhanced tolerance to sulfur contained in the feed.