“…However, the homogeneous catalytic process is generally unaccepted as a preferential alternative, as recovery and reuse of the expensive metals are difficult and most of the reactions do not proceed without the use of expensive ligands. Heterogeneous catalysts (noble metal catalysts such as Au,, , Pd, Pt,, and Ru, , ) have many advantages over their homogeneous counterparts, including easy removal from reaction mixtures and recyclability. Ru catalysts, especially those supported on high‐surface‐area heterogeneous catalyst supports, are recognized as promising catalysts for the catalytic hydrogenation of nitro compounds because of their high catalytic activity and low cost , , .…”