Catalytic Hydrogenation Of Benzoic Acid In Binary Solvent Mixture

Abstract

Hydrogenation of benzoic acid was carried out using different ruthenium catalyst at 493 K and hydrogen pressure of 6.89 MPa. A binary solvent consisting of 1, 4-dioxane and water was used for the hydrogenation. The dioxane-water composition of 1:1 gave 100% conversion using 5% Ru/C catalyst and 86% selectivity to cyclohexane carboxylic acid for hydrogenation of benzoic acid. Binary solvent was also observed to increase selectivity of benzoic acid hydrogenation towards cyclohexane carboxylic acid with catalysts like 5% Ru/C, 1%Ru-6%Re/C, 5%Ru/Al2O3 and 5%Ru/TiO2. The binary solvent has higher hydrogen solubility and also reduced the hydrogenolysis products like toluene and methyl cyclohexane.