Search results for "Incipient wetness impregnation"
showing 4 items of 4 documents
Pd and PdAu on mesoporous silica for methane oxidation: Effect of SO2
2007
Abstract Palladium and gold–palladium catalysts supported on mesoporous silica were prepared by incipient wetness impregnation. They were characterized by XPS, XRD, BET, and FTIR acidity measurements. The activity was tested in the oxidation of methane under lean conditions. The effect of adding SO 2 to the reactant mixture was investigated. Test reactions were consecutively performed to evaluate the thermal stability and poisoning reversibility. The palladium catalyst performed quite well in terms of the light-off temperature ( T 50 300 °C) and SO 2 tolerance. Moreover, the activity, which decreased after a night treatment in SO 2 at 350 °C, was completely recovered in subsequent cycles. …
Interaction of Ni/SiO2 with thiophene.
2009
Abstract The interaction between Ni/SiO 2 (18 wt%) and thiophene was studied by thermal gravimetric analysis (TGA) and in a fixed-bed reactor. The samples were prepared by incipient wetness impregnation and reaction was realized in hydrogen flow at 280–360 °C in the presence of 10–40 mbar of thiophene. It is found that sulfidation of Ni is not complete in TGA experiments and the maximum achievable transformation degree depends not only on the temperature and thiophene pressure, but also on the sample weight and the gas flow rate. The maximum transformation degree is shown to vary reversibly when conditions are changed. Analysis of the reaction products during sulfidation in a fixed-bed reac…
Reaction of thiophene with mono- and bimetallic Ni–Co particles supported on γ-Al2O3 and HDS activities of obtained sulfides
2009
Abstract Reaction between thiophene and M/γ-Al2O3 (20 wt.%, M = Ni, Co, 2Ni–Co and 2Co–Ni) was studied by thermal gravimetric analysis (TGA) and by sulfidation in a fixed bed microreactor. The samples were prepared by incipient wetness impregnation followed by drying and reduction in hydrogen flow at 450 °C. Formation of bimetallic particles in samples containing both Ni and Co was confirmed by HRTEM with EDX analysis. The reaction with thiophene (20 or 40 mbar) was done at 360 °C in hydrogen atmosphere. TGA of the reaction with thiophene revealed that the initial rate of sulfidation drops sharply when going from Ni/γ-Al2O3 to Co/γ-Al2O3 (by a factor of 40 under used conditions). It follows…
Hydrodesulfurization cobalt-based catalysts modified by gold
2007
Cobalt catalysts supported on amorphous SiO2 and ordered mesoporous silica (MCM-41) were prepared by incipient wetness impregnation. Gold was added by consecutive impregnation or by co-impregnation. The materials were characterised by XPS, XRD and TPR techniques and evaluated in the hydrodesulfurization (HDS) of thiophene in order to investigate the effect of the noble metal on the structure and on the catalytic behaviour of the supported cobalt. Co/MCM-41 exhibited higher HDS activity and higher stability than the Co/SiO2. Moreover, in contrast to silica case, the gold impregnated MCM-41, produced an enhancement of the cobalt catalytic activity, and this is likely to be related to an incre…