Oxidation of Toluene by Air in the Presence of Oxygen Compounds on Vanadium Catalysts

Abstract

Addition of 10 - 30 vol.% of C₁ - C₄ alcohols, acetone, acetic acid or acetic anhydride to toluene increases several times the yield of benzaldehyde. The effect of these compounds over V₂O₅-K₂SO₄ catalysts supported on SiO₂ is positive at molar ratio K₂SO₄ : V₂O₅ < 0.5. At the ratio K₂SO₄ : V₂O₅ ≥ 0.5 the effect is more complex and depends on the conditions used. In the case of V : Ag : K catalyst with the molar ratio 1 : 0.3 : 0.3, added compounds increase the yield of benzaldehyde, except 2-propanol. No effect of these additives was observed over H₉PV₆Mo₆O₄₀ catalyst supported on SiO₂.