Propane oxidative dehydrogenation over low temperature rare earth orthovanadate catalysts prepared by peroxyl method

Abstract

The high purity rare earth orthovanadates were prepared by the peroxyl method, and found to be a kind of the low temperature catalysts for propane oxydehydrogenation effectively at 320 degrees C. The catalytic performances of LnVO(4) (Ln=Y, Ce similar to Yb) were much better than those of rare earth orthovanadate catalysts and also slightly exceeded that of magnesium orthovanadate Mg-3(VO4)(2) reported in literatures. LnVO(4) (Ln=Y, Ce-Yb) were tetragonal active phases which could stabilize the existence of active sites for propane oxydehydrogenation. The catalysts with a small amount of LnVO(3) reduced from LnVO(4) (Ln=Dy similar to Yb) under reaction atmosphere exhibited better redox properties and catalytic performances possibly due to the existence of biphasic synergy catalysis. LaVO4 was monoclinic unstable active phase, although its bulk structure did not change after reaction, it could not stabilize the existence of surface active sites, leading to the remarkable deactivation of LaVO4 catalyst.