Synthesis, characterisation and catalytic applications of sol–gel derived silica–phosphotungstic acid composites

摘要: Abstract Phosphotungstic acid (HPWA)–silica composites were synthesised upto 80 wt.% HPWA loading both by conventional impregnation and sol–gel incorporation techniques. The samples characterised BET, XRD, NMR, FT-IR TG. A comprehensive study on the effect of acidity has been performed using pyridine adsorption, NH3 TPD a catalytic test reaction. containing 50 wt.% showed best overall performance. Although, acidic properties impregnated catalysts superior to their counterparts, stability measurements (XRD, reaction) before after washing with H2O/EtOH mixture have unambiguously proved that derived are more suitable for purposes heterogeneous catalysis.