Preferential orientation of VOHPO4 center dot 0.5H(2)O prepared by reducing VOPO4 center dot 2H(2)O with alcohol

VOHPO4 . 0.5H(2)O was prepared by reducing VOPO4. 2H(2)O with various alcoh ols and then calcinated in n-butane/air to produce the final catalysts. The preferential orientation of VOHPO4.0.5H(2)O and the influence of the prefe rential exposition of the plane of the final catalysts on catalytic oxidati on of n-butane to maleic anhydride (MA) were investigated. VOHPO4 . 0.5H(2) O with rose-like or twist agglomerated type structure prepared by reducing VOPO4 . 2H(2)O with primary alcohol orientates preferentially the (220) pla ne, the final catalyst contains only (VO)(2)P2O7 phase, the (020) plane is preferential exposition. VOHPO4 . 0.5H(2)O with platelet type structure pre pared by reducing VOPO4 . 2H(2)O with secondary alcohol orientates preferen tially the (001) plane, the final catalyst is composed of (VO)(2)P2O7, VOPO 4 and amorphous phase, and the exposition of the (020) plane of (VO)(2)P2O7 is less. The XRD patterns of VOHPO4 . 0.5H(2)O prepared from cyclohexanol, benzyl alcohol and 3-methyl-3-enanthol are similar to that prepared from s econdary alcohol. VOHPO4 . 0.5H(2)O derived from V2O5/isobutanol/H3PO4 (ord inary method) has no the preferential orientation of the plane. The results show that the catalytic properties of the final catalyst prepared from 1-o ctyl alcohol for the oxidation of n-butane to MA are superior to that of th e catalyst derived from 2-octyl alcohol and ordinary method.