| 摘要 |
<p>Catalyst for gaseous phase oxidation of o-xylene for phthalic anhydride production consists of a support impregnated with a silicate enamel and coated with a catalyst layer based on titanium and vanadium oxides. The support may be beads of fused refractory material bonded with a (boron silicate) coating of fusion point 800-1200 degrees C e.g. 20-60 wt.% SiO2, 3-15% Al2O3, 0.5-16% CaO, 1-15% K2O and Na2O and 2-40% B2O. Air and o-xylene are in molar ratio 69-130 and are heated at 360-445 degrees C. The catalyst has high activity and gives high yields with improved selectivity and is mechanically stronger than known catalysts.</p> |
