**3.1. Catalyst screening study for hydrogenation of aromatic carboxylic acid**

For catalyst screening study, hydrogenation of benzoic acid was carried out with different supported monometallic catalysts such as Pd, Ru, Re, and Co and bimetallic catalysts such as Ru-Re/C, Ru-Sn/Al<sup>2</sup> O3 , and Pd-Re/C. For hydrogenation of benzoic acid, metal catalysts such as Co and Ru-Co were also used. The selectivity as well as activity for hydrogenation of benzoic acid was found to be dependent on the catalysts used. The results on catalyst screening study for hydrogenation of benzoic acid are discussed below.

## *3.1.1. Hydrogenation of benzoic acid with 5% Pd/C catalyst*

It was observed that the aromatic ring was selectively hydrogenated to give cyclohexane carboxylic acid (CCA) as shown in **Scheme 1**. A 59.7% conversion of benzoic acid (BZA) with 100% selectivity to cyclohexane carboxylic acid was achieved.
