the effects of electronic properties of inner and outer surfaces of carbon nano tubes (cnts) on the deactivation of cobalt fischer-tropsch (ft) catalysts were studied. the comparative characterization of the fresh and used catalysts by tem, xrd, tpr, bet and h2 chemisorption showed that cobalt re-oxidation, cobalt-support interactions and sintering are the main sources of catalyst deactivation....

The gasification of biomass is a promising technique to generate different forms of valuable alternative energy, including direct thermal energy and further conversion of synthesis gas to clean liquid fuels or chemicals via Fischer– Tropsch synthesis (FTS) [1–5]. The ideal H2/CO ratio for FTS is ~2/1 based on the stoichiometry. However, The H2/ CO for the synthesis gas obtained from biomass gas...

Pt impregnated on a Sn-beta catalyst results in a very promising catalyst for the selective hydrogenation of α,β-unsaturated aldehydes, compared to the PtSn co-impregnated beta catalysts. Framework tin ions in the Sn-beta sample stabilize the nucleation of platinum nanoparticles inside the zeolite channel. These Pt(0)-Sn(4+) sites, which are only observed in the Pt/Sn-beta catalyst, have been s...

This study introduces a green and efficient method for preparation of biologically-active substituted 4H-pyrans using the one-pot three-component reaction of aromatic aldehydes, dimedone and malononitrile in the presence of cobalt oxide nanoparticles. Co3O4 nanoparticles were used as an efficient catalyst for the synthesis of polyhydroquinoline derivatives by the reaction ...

Hydrogen production through steam reforming of ethanol was investigated with conventional supported nickel catalysts and a Ni-containing smectite-derived catalyst. The former is initially active, but significant catalyst deactivation occurs during the reaction due to carbon deposition. Side reactions of the decomposition of CO and CH4 are the main reason for the catalyst deactivation, and these...

In the present research, silica bonded n-propyl-1,3,5-triazine-2,4,6-triamine (SPTT) was synthesized by direct incorporation of chloropropyl groups through co-condensation of tetraethyl orthosilicate (TEOS) and 3-chloropropyl trimethoxysilane (CPTMS) and subsequent grafting the melamine onto the propyl groups via simple nucleophilic substitution reaction. The catalyst has been characterized by ...

in this work the kinetic data demanded for kinetic modeling were obtained in temperatures 350, 400, 450 and 500 oc by conducting experimentations on a fe-cr nanocatalyst prepared from a novel method and a commercial fe-cr-cu one. the collected data were subjected to kinetic modeling by using two models derived from redox and associative mechanisms as well as an empirical one. the coefficients o...

Vanadium-modified (SiO2/MgO/MgCl2)•TiClx Ziegler-Natta catalysts were prepared through co-impregnation of water-soluble magnesium and vanadium salts under different pH values. Several key factors such as pH value of co-impregnation solution during catalyst preparation, catalyst performances including catalytic activity, ethylene/1-hexene copolymerization and hydrogen response were investigated....

In this work, a non-precious metal catalyst consisting of Co9S8 nanoparticles surrounded with nitrogen-doped graphene-like carbon (Co9S8-N-C) was developed for oxygen reduction in alkaline media. Improved activity has been measured with the Co9S8-N-C catalyst relative to Pt/C and a non-precious metal catalyst based on Fe instead of Co (Fe-N-C). An extensive physical characterization, including ...

A combination of characterization techniques has been employed to obtain a full description of the structure and chemical state of a series of Co-W/SiO2 catalysts used for the production of single-walled carbon nanotubes (SWNT) by CO disproportionation at 750-950 °C. The state of Co and W on a series of silica-supported catalysts has been investigated using extended X-ray absorption fine struct...