Preparation, Solid‐state Characteristics, and Catalytic Properties of Promoted Vanadium Phosphate Materials

Abstract

Abstract The syntheses of transition metal promoted (M = Co, Cr, Fe, Mo) supported vanadium phosphate (VPO) catalysts (TiO 2 (anatase), γ‐Al 2 O 3 ) and their characterization by N 2 ‐adsorption, X‐ray diffractometry (XRD), FTIR‐spectroscopy and determination of V‐valence state is reported. The catalytic properties were checked in the heterogeneous catalytic ammoxidation of 2, 6‐dichlorotoluene to the corresponding nitrile. The catalyst samples were prepared by synthesis of the precursor compound VOHPO 4 · 0.5 H 2 O, impregnation using various metal salt solutions and mixing with the support materials. The characterization revealed increased surface areas for all the promoted samples in comparison to the basic materials. XRD showed the formation of (VO) 2 P 2 O 7 after calcinations as well as patterns of support materials (anatase, γ‐Al 2 O 3 ). The formation of crystalline proportions of mixed oxides were not observed. The catalytic ammoxidation runs revealed a significant effect of the promoter metals on the catalytic properties by an increase of yield by ca. 20 % compared to bulk VPO. Almost complete conversion of 2, 6‐dichlorotoluene and 81 % yield of nitrile were observed using a 25 %VPCoO/γ‐Al 2 O 3 catalyst.