Preparation, Characterization And Property Of New Precursors Of V-P-O Catalyst For N-Butane Oxidation To Maleic Anhydride

In this paper,precursor,VOHPO₄ · 0.5H₂O,has been prepared by reducing VOPO₄ · 2H₂O with alcohols; VOHPO₃ · 1.5H₂O and VOPO₄ · 2H₂O prepared and has been characterized though a combination of techniques including XRD,IR,SEM,TG etc.Precursor,VOHPO₄ · 0.5H₂O,has been prepared by reducing VOPO₄ · 2H₂O with 1- and 2-C_4-10 straight chain alcohols;Benzyl alcohol;Cyclohexanol;3-Methyl-3-enanthol and mixed alcohol of 1-pentanol+2-pentanol(50%v), Isobutanol etc.Precursors prepared from 1- alcohols comprise VOHPO4 · 0.5H₂O crystals for which the [220] reflection is virtually the only feature of the diffraction pattern,this exhibits [220] plane preferred orientation;whereas precursors prepared from 2-alcohols give VOHPO₄ · 0.5H₂O crystals for which the [001 ] reflection is the dominent feature of the diffraction pattern,this shows [001] plane preferrred orientation.Precursors prepared from Benzyl alcohol; Cycloheanol;3-Methyl-enanthol are the same as 2-alcohol. Precursor prepared from isobutanol gives VOHPO₄ · 0.5H₂O crystal for which reflection is not the feature of diffraction pattern.Precursor , VOHPO₄ · 0.5H₂O,prepared from 1-alcohol are activated in mixed gas of air + n-butane, resultants are (VO)₂P₂O₇ and amorphous phase; Precursor, VOHPO₄ · 0.5H₂O prepared fromV₂O₅/isobutanol /H₃PO₄ is activated at the same as condition of activation,resultants consist of (VO)₂P₂O₇ phase ,a samall quantity of VOPO₄ and amorphous phase; Precursor , VOHPO₄ · 0.5H₂O,prepared from 2-alcohol is trartformed ,under the activationcondation ,topotactically to VOPO₄ phase , amorphous phase;and a little (VO)₂P₂O₇ phase ; Precursor , VOHPO₄ · 0.5H₂O,prepared from 1-alcohol are activated in air , resultants are amorphous phase ,vanadium phosphous mica,VOPO₄ and (VO)₂P₂O₇. Precursor , VOHPO₄ · 0.5H₂O,prepared from 1-...