Zirconia supported phosphotungstic acid as an efficient catalyst for resorcinol tert-butylation and n-heptane hydroisomerization

The alkylation of resorcinol with tert-butanol was carried out using zirconia supported phosphotungstic acid (PTA) as catalyst in liquid phase conditions. Among the different PTA loaded catalysts, the 15% PTA/ZrO2 calcined at 750degreesC was found to be the most active and yielding 4-tert-butyl resorcinol and 4,6-di-tert-butyl resorcinol as the major products under the optimized reaction conditions. In addition to the above, hydroisomerization of n-heptane was studied under vapor phase conditions using bifunctional catalysts comprising Pt, Pd and Pt-Pd clusters on 15% PTA/ZrO2. The catalytic activity of the bimetallic Pt-Pd catalyst is higher than that of the monometallic Pt and Pd catalysts. The catalysts prepared from acetylacetonate complexes were more active than those prepared from amine complexes. Addition of Pd has no beneficial effect on the catalytic performance when the bimetallic catalyst is prepared from acetylacetonate complexes. (C) 2004 Elsevier B.V. All rights reserved.