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Abstract
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Natural cellulose was extracted from Sesbania sesban plant by acid hydrolysis. A novel bio-microhybrid catalyst was prepared by coordinative anchoring of iron (III) meso-tetraphenylporphyrin complex Fe(TPP)Cl on the natural polymer, cellulose (PSAC). This biomimetic hybrid was characterized by thermogravimetric analysis (TGA), FT-IR, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and scanning electron microscopy (SEM). TGA analysis of PSACs showed their high thermostability. The amount of porphyrin loading on the cellulose was determined by ICP-AES. Each gram of heterogeneous catalyst contained 117 μmol Fe(TPP)Cl complex. SEM images of PSACs showed the fibril morphology of this composite material, with fibril sizes of 6-15 μm. This biopolymer material was used as a renewable and recoverable heterogeneous catalyst in the oxidation of sulfides to related sulfones, and of alcohols to related aldehydes or ketones. This system was performed in water as a green solvent by using meta-chloroperoxy benzoic acid (m-CPBA) as an oxidant. The effects of different factors, such as various oxidants, temperature, amount of catalyst, amount of oxidant and reaction time, on the yield of the reactions were considered. The oxidation of alcohols and sulfides occurred with high conversion rate and selectivity under the catalytic activity of this separable catalyst. The practical reusability of this catalyst was confirmed by its recycling.
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