Impregnação do ácido 12-fosfotúngstico em sílica - Parte I: determinação de parâmetros de impregnação, caracterização e avaliação da atividade catalítica

Abstract

Catalyst based on Kegging-type heteropolyacids (H 3PW 12O 40 - HPA), supported on SiO 2 (H 3PW), were prepared by the impregnation method under different thermal treatment conditions. The materials were characterized by different instrumental techniques and used as catalysts in the methyl esterification reactions of stearic acid. Using the catalyst with 15% of HPA, conversions higher than 60% were obtained after 2 h of reaction at 65 °C. Recovery studies using hot-filtration with ethanol at 75 °C showed satisfactory activity for two additional reaction cycles.