Effect of Ⅲ B metals (Sc, Y, La and Ce) on active components regulation of VPO catalyst in n-butane selective oxidation

Abstract

Vanadium phosphorus oxide (VPO) catalyst has been modified by the Ⅲ B elements (Sc, Y, La, Ce) have been prepared. Those catalysts were tested in n-butane selective oxidation, and it was shown that Y-VPO catalyst has the highest maleic anhydride (MA) yield among the studied catalysts. The VPO catalyst was characterized by a series of techniques. As evidenced by property characterization in conjunction with catalytic performance, we found that the presence of rare earth metals alters the phase composition of VPO catalyst. And then, the acidity of VPO catalyst was adjusted. Finally, the change of acidity could impact the n-butane activation process, which affected the n-butane conversion. Moreover, the rare earth metals also modulated the ratio of lattice oxygen and surface oxygen and then the MA selectivity.