Medium-pore (diameter ~ 6A) zeolites such as ZSM-5 and silicalite impregnated with Group VIII metals provide selective catalytic pathways for the conversion of synthesis gas to gasoline or olefins. Mössbauer and magnetic studies on these catalysts containing iron or iron plus cobalt are reported. The zeolites were impregnated with metal nitrate solutions, reduced, and carbided to yield showed F...

Abstract Dehydroaromatization of methane (MDA) reaction was investigated over platinum modified Mo/H-ZSM-5 catalysts which were pre-carbided at 750 °C. The influence on the catalytic performance and product selectivity for MDA 700 °C studied. presence led to a slight decrease in conversion from 7.5 4.2%. Aromatic selectivities above 90% obtained with containing low loadings (0.5 1.0 wt.%), benz...

sorption results9 revealed that the iron surface was mostly covered by promoter oxides of AI, Ca, and K. Postreaction XPS results also revealed a C( Is) XPS peak of weak to moderate intensity centered at 284.1-283.7 eV. This binding energy approaches those (ca. 283.5 eV) reported for iron cat bide^.^^*'^ More convincing evidence for carbide formation was obtained from TPHT results collected aft...

In our previous paper [I] we reported that the presence of P, S and Cl adatoms on Ni(lO0) surface causes a reduction of CO and Hz adsorption rate and adsorption binding energy. In the case of Cl and S the observed poisoning effect is stronger than the predicted one by a simple adsorption site blocking model and it increases in the sequence P, S, Cl. Since Cl, S and P have similar atomic radii w...