a study was made of the coking of a commercial fresh sulfide ni-mo/al2o3 catalyst in a fixed-bed reactor. the catalyst was coked using different coke precursors in the gas oil under accelerated conditions at temperatures of 400 to 450°c to yield different deactivated catalysts containing 2-20 wt% c. two cases were studied; crushed catalyst without diffusional resistance and extruded pellets wit...

an extensive study of fischer-tropsch synthesis (fts) on alumina-supported cobalt catalysts with different amounts of cobalt is reported. up to 40 wt % of cobalt, is added to the catalysts by impregnation method. the effect of the cobalt loading on the reducibility of the cobalt oxide species, dispersion of the cobalt, average clusters size, water-gas shift (wgs) activity and activity and selec...

Catalyst selectivity is associated with well-defined homogeneous active sites. Transition metal complexes and organocatalysts are highly active and selective in the homogeneous phase, and their heterogenization by incorporating them into inorganic solid materials allows combining their excellent catalytic activity with improved separation, recovering and recycling properties. In this article, w...

a fi zr-based catalyst of bis[n-(3,5-dicumylsalicylidene)-2′,6′­diisopropylanilinato]zirconium(iv) dichloride was prepared and used for polymerization of ethylene. the effects of reaction conditions on the polymerization were examined in detail. the increase in ethylene pressure and rise in polymerization temperature up to 35 oc were favorable for catalyst/mao to raise the catalytic activity as...

Two novel hydrodesulfurization (HDS) catalysts: FeN4/C and FeN2/C, were prepared using an impregnation-pyrolysis method. The two materials were investigated as catalysts for hydrodesulfurization (HDS) and hydrodearomitization (HDA) of model compounds. The turnover frequency of the two FeN catalysts is comparable to (FeN4/C) or even higher (FeN2/C) than that of MoNi/Al2O3. The FeN4/C catalyst al...

bis-(l-tyrosinato)copper(ii) was reacted with 3-(chloropropyl)-trimethoxysilane functionalized silica that has infused magnetite to yield a magnetically separable catalyst in which the copper carboxylate is covalently linked to the silica matrix through the silane linkage. the immobilized catalyst has been characterized by spectroscopic studies (such as ft-ir, epr, magnetic measurement, sem) an...

the reaction of 3-chloropropyl boehmite nanoparticles with caffeine and sulfuric acid afforded bnps-3-propyl-imidazolopyridinium hydrogen sulfate [bnps-caff]hso4 as a new bnps-supported ionic liquid (il) catalyst. [bnps-caff]hso4 proved to be an efficient heterogeneous catalyst for the synthesis of pyrazolopyranopyrimidines via a one-pot four-component reaction of hydrazine hydrate, ethyl aceto...