Applied Catalysis A: General, Vol.131, No.1, 43-54, 1995
Importance of a Quasi-Stable V4O9 to Synthesize a Highly Crystalline Vohpo4-Center-Dot-0.5H(2)O
The organic solvent method to synthesize a highly crystalline VOHPO4 . 0.5H(2)O was investigated. Firstly, reduction of V2O5 in alcohols was studied. It was clear that there existed a quasistable V4O9 state after reduction with isobutyl alcohol. When a mixture of isobutyl alcohol and benzyl alcohol was used, the reduction was relatively rapid and difficult to control. Secondly, pure, uniform and rose-shaped precursor VOHPO4 . 0.5H(2)O was obtained by the dehydration-condensation of V4O9 and ortho-H3PO4 when ortho-H3PO4 was added dropwise. The balance in rates between addition of ortho-H3PO4 and the dehydration-condensation was important to prepare a uniform precursor.
Keywords:PHOSPHORUS OXIDE CATALYSTS;MALEIC-ANHYDRIDE;VANADYL PYROPHOSPHATE;SELECTIVE OXIDATION;N-BUTANE;PHASE;BUTENE