Preparation of vanadium phosphate catalyst precursors for the selective oxidation of butane using alpha,omega-alkanediols

Vanadium phosphate catalyst precursors were prepared from V2O5 and H3PO4 or VOPO4 center dot 2H(2)O using alpha,omega-alkanediols (1,4-butanediol, 1,5-pentanediol and 1,6-hexanediol) as both the reducing agent and the solvent. A series of layered VOHPO4 center dot HO(CH2)(n)OH (n=4-6) materials intercalated with alpha,omega-alkanediols were obtained. The performance for butane oxidation of the final catalysts formed via the in situ transformation of the VOHPO4 center dot HO(CH2)(n)OH precursors under reaction conditions is described. The final catalysts derived from the alkanediol intercalated materials were found to exhibit relatively low selectivities to maleic anhydride and comprised of V-V (VOPO4) phases with an amorphous V-IV phase. However, when a crystalline ((VO)-O-IV)(2)P2O7 phase is present, with small amounts of V-V phases, as with materials prepared with 1,4-butanediol, the specific and intrinsic catalytic activity are higher. (C) 2011 Elsevier B. V. All rights reserved.Chemistry, AppliedChemistry, PhysicalEngineering, ChemicalSCI(E)EI0ARTICLE152-5718