Ileana D. Lick

Catalytic combustion of soot with a O2/NO mixture. KNO3/ZrO2 catalysts

Abstract Catalysts containing 0.25–20% KNO3 supported on ZrO2 have been studied for diesel soot combustion. The addition of KNO3 to ZrO2 support enhances its activity due to the increased contact between soot and catalyst and also because the KNO3 acts as catalyst. The combustion temperature has been measured for “loose” and “tight” contact, between soot and catalyst, and the difference was 10 K for KNO3(20)/ZrO2 catalyst. This finding is very important because under practical conditions the contact between soot and catalyst is poor and this contact resembles the contact denoted as “loose contact”.

The catalytic activity of Co/ZrO2 for NO reduction with propane in O2 presence

The selective catalytic reduction (SCR) of NO by propane in the presence of excess oxygen was studied on a Co/ZrO2 catalyst. This system is present as active for the NO reduction to N2. It was found that the addition of Co could improve the activity and selectivity of propane towards NOx reduction. The activity depends strongly on the space velocity (GHSV) when the system works with low oxygen concentration and it is independent of the space velocity when the system operates with excess oxygen. The water vapor present in the feed produces deactivation in the catalyst as well as in the support.

Total oxidation of propane and naphthalene from emission sources with supported cobalt catalysts

Propane and naphthalene combustion reactions were studied in the presence of CoOx/SiO2 catalysts. The catalysts were prepared by impregnation with four different levels of concentration (1, 5, 10 and 15 wt%) and characterized by several physicochemical techniques such as BET, DRX, SEM–EDS, TPR and UV–Vis DRS. TPR and UV–Vis DRS results reveal the presence of Co3O4-type species in all the studied catalysts, which are the active species for the combustion of both hydrocarbons. CoOx(5)/SiO2, which was the most active catalyst for the combustion of propane, presented also Co(II) ions in an octahedral environment, and this phase was the one responsible for the increase of the activity. For naphthalene combustion, the catalytic activity depends on the metal loading, the catalysts with higher loading being more active.

Co-Rh modified natural zeolites as new catalytic materials to oxidize propane and naphthalene from emission sources

Abstract Natural zeolites as a raw material to prepare catalytic precursors for the oxidation reaction of linear and poly-aromatic hydrocarbons are reported in this work. The process consisted in the formation of mono- and bi-metallic species containing Co and Co-Rh on natural zeolite tuffs. The materials are analyzed by different physicochemical techniques and used as catalysts for propane and naphthalene oxidation in emissions sources. Comparatively, Rh-zeolites are the most active catalysts for propane conversion. In this case, the formation of mixed oxides seems to be conditioned by surface properties. It could also be suggested that the Rh incorporation on a non-active phase in bimetallic catalysts impacts the effectiveness of the system. In addition, the NO presence increases the activity of bimetallic materials. Rh-Co zeolite systems markedly influence the naphthalene combustion temperature. Whereas in the absence of a catalyst a conversion rate of 50% and 100% is reached at 430 °C and 485 °C, respectively. It is interesting to observe that for RhCoCli-Mor and RhCoCli catalyst the 100% conversion is reached at 250 °C.

NO reduction with C3H8 on Co/Al2O3 catalyst. effect of O2 concentration

The selective catalytic reduction (SCR) of NO by propane in excess oxygen-containing gas mixture was studied on Co/Al2O3 catalyst. The oxygen concentration is very important for the reaction. The NO conversion to N2 without oxygen is 3% at 800 K and when the O2 concentration is raised up to 8% the NO conversion reaches its maximum value of 60% at 800 K. Characterization results by TPR and UV-Vis spectroscopy show that in the catalyst, species strongly interacting with tetrahedral and octahedral Co2+ ions in the support are present.

Zirconia-Supported Copper and KNO 3 Catalysts for Diesel Soot Combustion. Deactivation by Hydrotreatment and SO 2

Fil: Mosconi, Sandra Mariela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico San Luis. Instituto de Investigaciones en Tecnologia Quimica; Argentina

Cobalt Supported on Zirconia. Selective Catalytic Reduction of NO Using Propane as Reducing Agent

Fil: Lick, Ileana Daniela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico la Plata. Centro de Investigacion y Desarrollo En Ciencias Aplicadas; Argentina