Catalytic Synthesis of Hydroquinone by Using Rh on Al2O3 Via Different Rout

Abstract

The catalytic synthesis of hydroquinoneutilize benzene as the starting material. The manufacture of hydroquinone by oxidation of phenol and 1,2- diisopropylbenzene. The first route begin with Friedel-Crafts alkylation of petroleum –derived benzene to afford cumene. Subsequent Hock-type, air oxidation of the cumene leads to formation of acetone and phenol. The phenol is oxidized by using 70%hydrogen peroxide either in the presence of transition metal or in formic acid solution where formic acid is the actual oxidant. The generated catechol and hydroquinone mixture is separated into its pure components by distillations. The second synthesis way, which is also manufactured, is the reaction with propene and benzene to1,4-diisopropylbenzene, which reacts afterwards to the hydroquinone. Nevertheless there are more than this two synthetic routes benzene reacts to nitrobenzene by using HNO3and H2SO4 and after that to the corresponding aniline. Next, benzoquinone is synthesized by a route employing stoichiometric amounts of MnO2 to oxidize aniline, followed by iron catalyzed reduction to the corresponding hydroquinone. While benzene is a volatile carcinogen derived from non-renewable fossil fuel feed stocks, an alternative way to hydroquinone has been elaborated. Glucose is nonvolatile, nontoxic, and derived from renewable plant polysacharrides and plays an important role for these benzene free 3-dehydroshikimic acid (DHS). Shikimicacid as well as quinic acid are known for the hydroquinone Synthesis. In this work the starting material for the hydroquinone synthesis using catalyzed by Rh/Al2O3,Rh/C, Pt/C, or Pd/c. The Rh on Al2O3 catalyst showed the best results (59% yield)