Intracellular biosynthesis of Au and Ag nanoparticles using ethanolic extract of Brassica oleracea L . and studies on their physicochemical and biological properties

Article history: Received 28 April 2014 Revised 29 September 2014 Accepted 11 October 2014 Available online 3 February 2015 High-surface-area mesoprous powders of γ-Al2O3 doped with Cu, Cr, and V ions were prepared via a modified sol–gel method and were investigated as catalysts for the oxidation of chlorinated organic compounds. The composites retained high surface areas and pore volumes comparable with those of undoped γ-Al2O3 and the presence of the transition metal ions enhanced their surface acidic properties. The catalytic activity of the prepared catalysts in the oxidation of 1,2-dichloroethane (DCE) was studied in the temperature range of 250–400°C. The catalytic activity and product selectivity were strongly dependent on the presence and the type of dopant ion. While Cuand Cr-containing catalysts showed 100% conversion at 300°C and 350°C, V-containing catalyst showed considerably lower conversion. Furthermore, while the major products of the reactions over γ-alumina were vinyl chloride (C2H3Cl) and hydrogen chloride (HCl) at all temperatures, Cuand Cr-doped catalysts showed significantly stronger capability for deep oxidation to CO2. © 2015 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.