Arachis hypogaea derived activated carbon/Pt catalyst: reduction of organic dyes

Activated carbon from agro waste groundnut (Arachis hypogaea) shell was prepared by chemical activation and used as support for dispersion of 5% platinum nanoparticles. The Pt nanoparticles were obtained by the reduction in hydrogen gas medium. The synthesized groundnut activated carbon/platinum catalyst was characterized by various techniques such as X-ray powder diffraction, electron microscopies and X-ray photoelectron spectroscopy. The catalytic behaviour of the synthesized catalyst was investigated by exploring it as catalyst for the reduction of various classes of dyes; namely, triphenylmethane dyes such as Malachite green, phenol red and bromophenol blue, xanthene dyes: rose bengal, rhodamine 6G, rhodamine B, thiazine dye: methyelene blue, azo dye: congo red and 4-nitrophenol by sodium borohydride in aqueous medium. Under suitable reaction conditions, for all tested dyes, cationic dyes were reduced at a faster rate than anionic dyes. The rate of reduction on the structure of dye and nature of catalyst was employed

Cu and Fe oxides dispersed on SBA-15:a Fenton type bimetallic catalyst for N,N-diethyl-p-phenyl diamine degradation

A bimetallic oxidation catalyst has been synthesized via wet impregnation of copper and iron over a mesoporous SBA-15 silica support. Physicochemical properties of the resulting material were characterized by XRD, N2 physisorption, DRUVS, FTIR, Raman, SEM and HRTEM, revealing the structural integrity of the parent SBA-15, and presence of highly dispersed Cu and Fe species present as CuO and Fe2O3. The CuFe/SBA-15 bimetallic catalyst was subsequently utilized for the oxidative degradation of N,N-diethyl-p-phenyl diamine (DPD) employing a H2O2 oxidant in aqueous solution

Preparation of mesoporous stannosilicates SnTUD-1 and catalytic activity in levulinic acid esterification

The direct synthesis of SnTUD-1 with different Si:Sn ratios (100, 50 and 25) by using non-surfactant template triethanolamine (TEA). It functioned as a structure-directing agent and assisted to graft the Sn ions into the TUD-1 silica layer. The physicochemical properties of these materials were examined with XRD, N2 sorption, DR UV–Vis, NH3-TPD, 29Si-NMR, HRTEM, XPS and pyridine adsorbed FT-IR studies, which indicated highly interconnected mesoporous structure with wormhole like morphology. Sn4+ ions were mainly tetrahedrically coordinated with silica; while increase of loading lead to the formation of nanocrystalline SnO2 with different sizes. Materials showed acidity in the range of 0.13–0.31 mmol/g. Synthesized catalysts were tested in the esterification of levulinic acid (LA) with various aliphatic alcohols and exhibited excellent activity. The catalyst was recycled five times without loss of its activity. © 2019 Elsevier Inc