Glycerol Conversion to Lactic Acid with Unsupported Copper Salts and Bulk Cupric Oxide in Aqueous Alkali Media.

Glycerol conversion to lactic acid (LA) was investigated in aqueous alkali over eight unsupported copper compounds (CuBr, CuBr, CuCl, CuCl, CuF, Cu(NO),CuO, and CuO) for studying the effects of anion and valence. Powder X-ray diffraction and scanning electron microscopy measurements indicated that these copper compounds were reduced to metallic copper with different morphologies. Divalent copper compounds exhibited much better performances than the corresponding univalent species, ascribed to their greater reduction heat and higher local reaction temperature.

Cyclodehydration of 1,4-butanediol over Zr-Al Catalysts: Effect of Reaction Medium.

The conversion of 1,4-butanediol (BDO) to tetrahydrofuran (THF) in aqueous phase is desirable because BDO production technology is shifting to bio-based aqueous fermentation routes. In this study, liquid-phase cyclodehydration of BDO to THF was studied in two reaction media (pure BDO and aqueous BDO feeds) at 200-240 °C using ZrO-AlO (ZA) mixed oxides, which were made with a co-precipitation method and were characterized with XRD, BET, SEM/EDX, pyridine and n-butylamine adsorptions. The maximum acidity and the largest surface area occurred at Zr/Al atomic ratios of 1/1 (ZA11) and 1/3 (ZA13), respectively.

Propylene Polymerization Catalyzed by Metallocene /Methylaluminoxane Systems on Rice Husk Ash.

Silica generated from agricultural waste is more cost effective and environmentally friendly than silica from traditional commercial processes. In this study, spherical silica particles with a diameter of around 120 nm were fabricated from rice husk ash (RHA), and were used to support two bridged zirconcene complexes ((I) MeSi(Ind)ZrCl and (II) CH(Ind)ZrCl ) for catalyzing propylene polymerization to produce polypropylene (PP) in a temperature range of 40-70 C and in a solution methylaluminoxane (MAO) range of 0.1-0.

Aqueous-Phase Hydrogenolysis of Glycerol over Re Promoted Ru Catalysts Encapuslated in Porous Silica Nanoparticles.

Activity improvement of Ru-based catalysts is needed for efficient production of valuable chemicals from glycerol hydrogenolysis. In this work, a series of Re promoted Ru catalysts encapuslated in porous silica nanoparticles (denoted as Re-Ru@SiO₂) were prepared by coating silica onto the surface of chemically reduced Ru-polyvinylpyrrolidone colloids, and were used to catalyze the conversion of glycerol to diols and alcohols in water. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) were used to characterize these nanoparticles.

Constrained Geometry Organotitanium Catalysts Supported on Nanosized Silica for Ethylene (co)Polymerization.

Supported olefin polymerization catalysts can prevent reactor-fouling problems and produce uniform polymer particles. Constrained geometry complexes (CGCs) have less sterically hindered active sites than bis-cyclopentadienyl metallocene catalysts. In the literature, micrometer-sized silica particles were used for supporting CGC catalysts, which might have strong mass transfer limitations.