a series of x(co, mn)/tio2 catalysts (x=2–12wt.%) containing 25%co and 75%mn were prepared by the co-impregnation method. all prepared catalysts have been tested in fischer-tropsch synthesis for production of c2-c4 olefins. it was found that the catalyst containing 8wt.%(co,mn)/tio2 is an optimal catalyst for production of c2-c4 olefins. the effect of operation conditions such as the h2/co mola...

Using wet impregnation method, a novel ternary system of silica supported Fe-Co-Ce catalyst was prepared. Preparation conditions such as impregnation time and temperature, drying time and temperature, were optimized by the L9 Taguchi experimental design to achieve a light olefin selective catalyst with maximum CO conversion in a fixed bed micro-reactor. It was found that the best conditions to ...

Magnetic, Mössbauer, and I.R. studies of nanosize particles of Fe and Co species dispersed in a cage of aluminosilicates structure, in relation to syngas (CO+H2) Fischer Tropsch conversion. The difference in the catalytic activity of such species have shown dependancy on their degree of dispersion. The carbonyl impregnation gave ultra-fine Super Paramagnetic Fe3O4, whereas the nitrate impregnat...

The Al, Zr, and Ti modified MCM-41 materials were prepared by the post-synthesis method, and then the Ni-W species were introduced on them by using the co-impregnation method in order to obtain high-performance hydrodenitrogenation (HDN) catalysts. The activity of the catalysts was evaluated by the HDN reaction of quinoline. The optimum HDN activity was observed on the catalyst sup...

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....

The effect of transition metal doping on Pt/Al2O3 catalyst used in propane dehydrogenation reaction at 500 ̊C was studied. The preparation methods investigated were sequential impregnation (Pt followed by the 2 metal or the 2 metal followed by Pt) and co-impregnation. The metal contents of these catalysts were fixed as the weight ratio of Pt per the 2 metal of around 0.075. These catalysts were ...

A weak surface modification is applied to Co/SiO2 catalyst by hydrothermal treatment at 180°C for 5 h. Aluminum is introduced to Co/SiO2 catalysts during the surface modification. The effects of surface modification on Co/SiO2 catalyst are studied by changing the operating sequences of surface modification and cobalt impregnation in the catalyst preparation. Surface modification before cobalt i...

Vacuum Impregnation in food industry is an interesting process particularly in semy-dry fruit processing. At the beginning of the process the pressure is reduced and the internal gas in the product pores is expanded and partially flows out, after that, when atmospheric pressure is restored and residual gas is compressed, the external liquid flows into the pores. Although vacuum impregnation pro...

The effectiveness of Mg as a promoter of Co-Ru/γ-Al2O3 Fischer-Tropsch catalysts depends on how and when the Mg is added. When the Mg is impregnated into the support before the Co and Ru addition, some Mg is incorporated into the support in the form of MgxAl2O3+x if the material is calcined at 550°C or 800°C after the impregnation, while the remainder is present as amorphous MgO/MgCO3 phases. A...

A straightforward method is presented to produce catalyst particle-filled carbon nanotubes. Based on capillarity and surface tension, a simple strategy was developed to selectively fill carbon nanotubes with Fe, Co, and Ni species using a two-step method consisting of impregnation and selective washing. By chosing the impregnation and washing solution properly, metal particles are produced excl...