文摘
The catalytic efficiency of takovite鈥揳luminosilicate鈥揷hromium catalysts obtained by adsorption of Cr3+ ions from aqueous solutions by a takovite鈥揳luminosilicate nanocomposite adsorbent is reported. The adsorbent was synthesized by the coprecipitation method. The catalytic activity of the final Cr鈥揷atalysts depended on the amount of adsorbed chromium. (Z)-cyclooctene conversion up to 90% with total selectivity for the epoxide was achieved when the oxidation was carried out with hydrogen peroxide, at room temperature. After five consecutive runs, the catalysts maintained high activity, although after the sixth reuse, the epoxide yields strongly decreased to 35%. The catalysts were also efficient for cyclohexane oxidation, reaching up to 18% conversion, with cyclohexanone/cyclohexanol selectivity close to 1.2. On the whole, their use as catalysts gives a very interesting application for the solids obtained by adsorption of a contaminant cation such as Cr3+.
Keywords:
takovite鈭抋luminosilicate nanocomposite; chromium; adsorption; catalytic oxidation