The complete oxidation of n-Hexane and iso-Octane was studied individually in a fixed bed tubular flow reactor over CuO-CeO2 catalysts synthesized via four different methods namely urea-nitrate combustion method, urea gelation/co-precipitation method, citric acid sol-gel method and co-impregnation method. Laser diffraction was employed in catalysts characterization. The results obtained from th...

Deactivation of cobalt and nickel catalysts in Fischer-Tropsch synthesis and methanation JAVIER BARRIENTOS Akademisk avhandling som med tillstånd av KTH i Stockholm framlägges till offentlig granskning för avläggande av teknologie doktorsexamen fredagen den 23 september kl. " True wisdom comes to each of us when we realize how little we understand about life, ourselves, and the world around us....

Homogeneous catalysts usually show higher catalytic activities than heterogeneous catalysts because of their high dispersion of catalytically active sites. We demonstrate here that heterogeneous catalysts of ionic liquids functionalized on superhydrophobic mesoporous polymers exhibit much higher activities in transesterification to form biodiesel than homogeneous catalysts of the ionic liquids ...

Over the last six years, highly active catalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide have been developed. Initial studies showed that bimetallic aluminium(salen) complexes [Al(salen)]2O formed active catalysts and kinetic studies allowed the catalytic cycle to be determined. The catalysts could be immobilized on silica, allowing them to be used in a gas phase...

Au/CeLaOx mixed oxide catalysts containing 0.5 to 1.0 wt% Au were prepared via coprecipitation with HAuCl4, the appropriate nitrate precursors, and either urea or Na2CO3 as the precipitant. BET surface area measurements for the Au/CeLaOx catalysts varied in the range of 16-107 m/g depending on the precipitant, aging time, and calcination conditions. The catalysts were tested for the selective o...

The catalytic oxidation of sulfur dioxide to sulfur trioxide over several binary (MxOy/TiO2) and ternary (V2O5/MXOY/TiO2) supported metal oxide catalysts was systematically investigated. The supported metal oxide components were essentially 100% dispersed as surface metal oxide species, as confirmed by Raman spectroscopy characterization. The sulfur dioxide oxidation turnover frequencies of the...

The field of asymmetric catalysis has progressed rapidly since the early 1980s, as judged by the increasing number of reports each year and the greater frequency with which enantioselective catalysts are employed in industry.1-3 This intense research effort has greatly expanded the variety of reactions that can be performed with good substrate generality and in a highly enantioselective fashion...

ZnO-supported palladium-based catalysts have been shown in recent years to be both active and selective towards the steam reforming of methanol, although they are still considered to be less active than traditional copper-based catalysts. The activity of PdZn catalysts can be significantly improved by supporting them on alumina. Here we show that the Pd/ZnO/Al2O3 catalysts have better long-term...

Metal nanoparticles are promising catalysts for dye degradation in treating wastewater despite the challenges of recycling and stability. In this study, we have introduced a simple way to prepare Au@polypyrrole (PPy)/Fe3O4 catalysts with Au nanoparticles embedded in a PPy/Fe3O4 capsule shell. The PPy/Fe3O4 capsule shell used as a support was constructed in one-step, which not only dramatically ...

In meeting the need for environmental remediation in wastewater treatment and the development of popular sulfate-radical-based advanced oxidation processes (SR-AOPs), a series of Co/Fe-based catalysts with confirmed phase structure were prepared through extended soft chemical solution processes followed by atmosphere-dependent calcination. Powder X-ray diffraction (XRD), scanning electron micro...