Study on the structure, acidic properties of V–Zr nanocrystal catalysts in oxidative dehydrogenation of propane

•The property of the catalysts is illustrated both on the surface and in the bulk.•V-doped catalysts generate Brønsted acid which affects the PODH reaction greatly.•The aggregation of vanadium species influences the catalytic performance.•The method of preparation makes the dispersion of V-doped species well. A series of V-doped zirconia nanocrystal (the molar ratio of V/Zr varying from 0.001 to 0.15) were prepared via hydrothermal method and performed in oxidative dehydrogenation of propane. It was found that vanadium was highly dispersed on the surface and in the bulk of ZrO2. The distribution of the vanadium species, the valence states and the aggregation state of V species on the surface, as well as the acid properties of the catalysts including kinds, number and strength were detected by the various characteristic methods. The correlation between the V content and the surroundings of the different V species has been studied. The function of acid properties, especially Brønsted acid in the catalytic performance has been discussed. Oxidative dehydrogenation reactions were carried out in a continuous flow fixed bed reactor and ZrV0.01 catalyst showed good conversion and selectivity with a yield of propylene of 21.3%.