Catalytic Efficiency of Palladium (II) Supported on Castor Oil Based Micelle Templated Silica for Peroxide Promoted Catalytic Wet Oxidation of Phenols

Abstract

This work reports on the catalytic efficiency of the micelle templated silica based supported palladium catalysts. The supports were prepared by one-pot co-condensation of organoaminesilanes and tetraethoxysilane with 1:4 and 1:9 loading ratios in presence of castor oil template. The supports and supported catalysts were characterized by acid titration, Atomic Absorption Spectroscope, Diffuse Reflectance Infrared Fourier Transform Spectroscopy and porosimeter. The loading of amino groups for the prepared materials ranged from 2.08 to 4.105 mmol g-1 while the loading of palladium ranged from 1.05 to 1.73% w/w. The presence of absorption bands at around 3600-3100 cm-1 reveals that the organoaminesilyl groups are successfully incorporated in each silica matrix prepared. The pore size distribution of these materials ranges from 2 to 20 nm with an average pore diameter of about 8 nm. The surface area of 3-aminopropyl functionalized micelle templated silica prepared by castor oil template is 428 m2 g-1 and a pore volume of 1.1024 cm3 g-1. The catalytic efficiencies range from 34.09 to 58.33% depending on the type of template used, organosilane to tetraethoxysilane ratio and, temperature at which the reaction was carried. The present investigation concludes that the catalysts are active on the oxidation of a mixture of phenols at 27°C and 70°C using hydrogen peroxide oxidant.