Vapor phase acylation of phenol with ethyl acetate over H3PO4/TiO2-ZrO2

ZrO2-TiO2 mixed oxides with a Ti and Zr molar ratio of 1/1 were prepared with and without surfactant by the sol-gel method. Catalysts containing 5-35% H3PO4 were prepared using these mixed oxides and the catalytic performance of each material for vapor phase acylation of phenol to 2-hydroxy acetophenone (2-HAP) was determined. During the reaction of phenol with ethyl acetate, 2-HAP was found to be the major product, when 4-hydroxy acetophenone was not detected in the product stream; phenylacetate (PA) and alkylated products were the minor products. In the best experimental conditions, the alkylated products were less than 0.5%. This reaction may represent an environmentally friendly alternative to use the ethyl acetate as the acylating reagent. The feed molar ratios of phenol/ethyl acetate were varied over a wide range (1-0.1), and the optimum feed ratio of phenol/ethyl acetate was 1:3. Space velocity employed in phenol acylation reported as WHSV (phenol) = 1.35 h(-1). The acylation reactions were carried out in the temperature range of 473-673 K and the optimum H3PO4 content for acylation was 15 wt.% H3PO4. (c) 2006 Elsevier B.V. All rights reserved.