A new use for modified sugarcane bagasse containing adsorbed Co2+and Cr3+ : catalytic oxidation of terpenes.

Abstract

This study describes the applicability of two chemically modified sugarcane bagasses containing eitheradsorbed Co2+or Cr3+ions as heterogeneous catalysts for the autooxidation of monoterpenes. The mainobjective was to investigate new uses for these adsorbent materials which had been previously employedfor treatment of aqueous solutions or effluents containing metals such as Co2+and Cr3+. The adsorptionefficiency of Co2+and Cr3+on SCB2 and EB was evaluated by adsorption isotherms and other techniquessuch as XRD, ICP-AES and TGA. Catalytic activity of the four new catalysts, SCB2-Co, SCB2-Cr, EB-Co, andEB-Cr, were assessed in the oxidation reaction of _-citronellol(1), (+)-limonene(2), and (−)- _-pinene(3)in a free solvent system. Results obtained demonstrated that these materials were promising catalysts forthe oxidation of monoterpenes. Reactant conversion ranged from 49 to 78% as determined by GC analysisand a combined selectivity up to 59% for the oxidation products was achieved.