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Iron-catalyzed tar decomposition is studied by inspecting changes in catalytic activity and its correlation to the metal oxidation numbers. A carbon-aerogel-supported iron (Fe/CAG) catalyst was used herein to decompose toluene (model tar) at between 500 °C and 700 °C. The catalytic decomposition was studied in a conventional reaction system, and the catalyst was characterized prior to and after the reaction to understand the effect of the structural changes in the catalytic activity. The results demonstrated that the iron oxidation state and coke deposition strongly depend on the reaction temperature. The X-ray diffraction patterns confirmed that at T

Alumina supported catalytic systems K–Me (Me = Cu, Co and V) for the simultaneous removal of soot and NO x , were prepared by impregnation of a powder particle size alumina, using nitrate solutions of the corresponding metals. Physico-chemical characterization of the prepared catalysts was performed by means of XRD, SEM-EDX, ICP, N 2 -adsorption and TPR. The activity of the catalysts was assayed both, by thermogravimetric analysis and in a laboratory-scale fixed bed reactor. The effect of catalyst composition was examined. The catalysts showed high activity on the simultaneous removal of soot and nitrogen oxides at temperatures between 350 and 550 °C. Full selective conversion of NO x and total oxidation of the soot was attained; observing higher reaction rates in the case of the catalysts prepared using Cu as the active metal.

Catalytic filters for the simultaneous removal of soot and nitrogen oxides were prepared by means of coating cordierite monoliths with alumina-based suspensions containing Cu, Co or V and K as the catalytically active phase. Textural and chemical properties of the coated monoliths were determined by means of N2-physisorption, XRD, SEM-EDX and temperature programmed reduction. Activity of the catalytic filters in the simultaneous removal of soot and nitrogen oxides was tested in a fixed bed installation in absence and in presence of steam and CO2. Complete soot oxidation was measured for some of the assayed catalytic filters, with high selectivity to CO2 formation. NO reduction was preceded by a peak of NO2 formation, which corresponded to maximum soot oxidation rate, pointing to the formation of NO2 as a key step in the reaction mechanism for the simultaneous removal. Presence of steam and CO2 diminished catalytic activity and selectivity for soot oxidation.