Nanorods-assembled CeVO4 hollow spheres as active catalyst for oxidative dehydrogenation of propane

Abstract CeVO 4 hollow sphere nanostructures have been prepared by a simple hydrothermal synthesis method. HRTEM investigation indicates that the CeVO 4 hollow spheres are assembled by small single crystal nanorods. Through a plus post annealing treatment at 500 °C, the CeVO 4 hollow spheres have more Ce 4+ species (Ce 4+ /(Ce 4+  + Ce 3+ ) is ca. 5%) in the surface compared with the as-prepared sample (ca. 1%) based on the XPS results. No CeO 2 and V 2 O 5 phases were examined by both XRD and Raman spectroscopy, which indicates that Ce 3+ –Ce 4+ /V 5+ –V 4+ coexist in the annealed CeVO 4 hollow spheres, confirmed by the existence of V 4+ detected by XPS. At 500 °C, the nanorods assembled CeVO 4 hollow spheres exhibits a rather very high selectivity (ca. 70%) for propylene in oxidative dehydrogenation (ODH) reaction of propane. The presence of Ce 4+ , which induces additional V 4+ in these hollow sphere nanostructures, is critical for the enhancement of selectivity of the catalyst.