Thermal analysis of K(x)/La2O3, active catalysts for the abatement of diesel exhaust contaminants

Potassium loaded lanthana is a promising catalyst to be used for the abatement of diesel exhaust pollutants. In this paper we have combined several thermal techniques to study relevant processes that take place during the soot combustion reaction. Temperature programmed oxidation (TPO) experiments show that with potassium loadings between 4.5 and 10 wt.% and calcination temperatures between 400 and 700 °C, these catalysts mixed with soot give maximum combustion rates between 350 and 400 °C. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) indicate that the reaction coexists with the thermal decomposition of bulk hydroxide species. For the La2O3 solid, the La(OH)3→LaO(OH) and LaO(OH)→La2O3 processes occur at ca. 360 and 500 °C, respectively, whereas the presence of K in the K(x)/La2O3 catalysts provokes a shift of these endothermic peaks to higher temperatures. In all the studied solids, oxycarbonates decompose in the 550–800 °C temperature range. On the other hand, microbalance results show that the bulk carbonate formation depends on both the potassium content and the calcination temperature. The High Frequency CO2 Pulses technique is useful to study the dynamics of the CO2 adsorption–desorption process and to characterize the surface basicity of the solids. When both La2O3 and K/La2O3 solids are calcined at 700 °C, a strong decrease on the CO2–surface interaction takes place, which correlates with a small decrease in catalytic activity and with an increase in the K/La surface ratio. These effects may be originated, at least in part, by a decrease in oxygen vacancies concentration and a thermal dehydroxylation of the catalysts.Fil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Querini, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Activity of Catalytic Ceramic Papers to Remove Soot Particles—A Study of Different Types of Soot

Diesel soot particles are of concern for both the environment and health. To catalytically remove them, it is important to know their structure and composition. There is little described in the literature on how catalysts favor the combustion of different soot fractions. In this work, programmed temperature oxidation (TPO) experiments were carried out using Co,Ce or Co,Ba,K catalysts supported on ceramic papers. Soot particles were obtained by burning diesel fuel in a vessel (LabSoot) or by filtering exhaust gases from a turbo diesel engine in a DPF filter (BenchSoot), and compared with a commercial diesel soot: Printex U. Various characterization techniques were useful to relate the characteristics of both the soot particles and the catalysts with the TPO results. The maximum catalytic soot burn rate (TM) temperatures were in the range of diesel exhaust temperatures that would facilitate in-situ regeneration of the DPF. The Co,Ba,K catalyst showed a higher catalytic effect in LabSoot, as the latter exhibited the largest primary particles and the higher order of graphene layers, for which the potassium-containing catalyst improves the contact between soot and catalyst and favors the combustion of soot, while the Co,Ce catalyst preferentially enhanced the combustion of commercial soot by supplying active oxygen.Fil: Leonardi, Sabrina Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Biomorphic synthesis of cobalt oxide and ceria microfibers: Their application in diesel soot oxidation

CeO2, Co3O4 and mixed Co3O4-CeO2 hollow microfibers were synthesized using cotton as biotemplate by incipient wetness impregnation (one step synthesis). Mixed Co3O4-CeO2 fibers were also prepared by incorporating cobalt onto CeO2 fibers by wet impregnation (sequential synthesis). A thorough characterization by BET, XRD, LRS, XPS, EDX and SEM was conducted to correlate the physical chemistry properties of the fibers with their catalytic performance. Ceria fibers showed a maximum combustion rate at TM = 420 °C. While cobalt fibers were even more active (TM = 365 °C), Co3O4-CeO2 fibers resulted in intermediate activity (TM = 380 °C). The good catalytic performance could be related to chemisorbed labile oxygen species (Oβ).Fil: Stegmayer, María Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

The first Linguatula serrata case in an imported dog in Finland

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Ceramic Fiber-Based Structures as Catalyst Supports: A Study on Mass and Heat Transport Behavior Applied to CO 2 Methanation

Fibrous structures present interesting characteristics as catalyst supports for heat- and mass-transfer-limited reactions. This paper investigates the mass and heat transport behavior of ceramic fiber-based catalysts (catalytic ceramic paper) by applying them to the exothermic reaction of CO2 methanation. Catalytic experiments were carried out to fit the activity of the catalysts with known kinetics. A fixed-bed reactor model was used to determine the efficiency and efficiency losses caused by different transport phenomena, as well as to perform a sensitivity study focused on heat transfer. The results show that heat transfer limitations are the main cause for losses in reactor efficiency, with steep temperature profiles developing inside the reactor. Poor heat transfer limits the development of highly active catalysts, while pressure drop restricts the flow rate and therefore the productivity. The use of ceramic materials with higher thermal conductivity and increasing the fiber diameter are promising approaches to enhance heat transfer, reduce pressure drop, and improve overall reactor performance.Fil: Sánchez, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Güttel, Robert. Universitat Ulm. Faculty Of Natural Sciences; Alemani

New Formulations of Ni-Containing Ceramic Papers to Enhance the Catalytic Performance for the Oxidative Dehydrogenation of Ethane

Ceramic papers composed of silica–alumina fibers structured using colloidal suspensions as binders constitute interesting materials to be used as flexible supports of catalytic materials. The deposition of Ni as the active ingredient together with Zr or Ce promoters resulted in active and selective structured catalysts for the oxidative dehydrogenation of ethane; these structured catalysts also exhibited acceptable mechanical properties. The employed binder agents (nanoparticles of ceria, zirconia, or yttria-stabilized zirconia) homogeneously covered the fiber surface, contributing to the dual function of building a three-dimensional arrangement and favoring the anchoring of the catalytic formulations. The prepared papers showed nickel oxide as the active phase. The incorporation of cerium or zirconium as promoters enhanced the catalytic properties. The former element mainly produced an increase in ethane conversion, whereas the latter markedly improved ethylene selectivity. In both cases, an ethylene productivity was obtained in the promoted systems which was higher than that in the unpromoted samples. It is likely that the formation of the solid solutions Ni–Ce–O and Ni–Zr–O, as suggested by X-ray diffraction and laser Raman spectroscopy analyses, plays an important role in these effects. The best catalyst was the one containing nickel as the active phase, Ce as the promoter, and ZrY as the binder agent, for which ethylene productivity at 400 °C was ca. 513 g ethylene/(kgcat h). The binder agent addition was necessary to join the fibers, thus improving the mechanical properties of the papers, but they also affected the catalytic performance through the coverage of ceramic fibers and the resulting interaction with the catalytic compounds. The performed tensile index tests showed that the colloidal suspension of ceria produced papers with mechanical properties better than those of zirconia or zirconia–yttria because they exhibited greater resistance and flexibility.Fil: Bortolozzi, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Banus, Ezequiel David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Ultrasound-Assisted Deposition of Co-CeO2 onto Ceramic Microfibers to Conform Catalytic Papers: Their Application in Engine Exhaust Treatment

The combination of the selective catalytic reduction technology with catalytic filters constitutes one of the most efficient ways for diesel engine exhaust treatment. In this paper, the development of catalytic ceramic papers as structured systems for the abatement of diesel soot particles is addressed. Ceramic papers were prepared by the dual-polyelectrolyte papermaking method, which is based on the conventional papermaking technique used for cellulosic papers, in which a portion of cellulosic fibers is replaced by ceramic ones. The deposition of Co and Ce as catalytic materials by the wet spray method on ceramic papers was studied for the development of structured catalysts using an ultrasonic nebulizer and different solvents. The use of alcohol-water solutions for the impregnation of cobalt generated smaller particles and a high dispersion of them on the ceramic fibers, greater than that obtained when pure water was employed. Temperature programmed oxidation (TPO) assays showed that the best catalytic performance was acquired with the catalysts generated with alcohol solvents, showing a maximum rate for soot combustion at a temperature close to 400 °C. The adequate soot combustion performance and the high thermal and catalytic stability make catalytic ceramic papers impregnated by the wet spray method, promising systems for their application as diesel particulate filters.Fil: Sacco, Nicolás Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Banus, Ezequiel David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Bortolozzi, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Simultaneous removal of soot and nitrogen oxides from diesel engine exhausts

In this paper, previously reported findings and new results presented here are discussed with the main objective of establishing the reaction mechanism for soot oxidation on different supports and catalysts formulations. Catalysts containing Co, K and/or Ba supported on MgO, La2O3 and CeO2 have been studied for diesel soot catalytic combustion. Among them, K/La2O3 and K/CeO2 showed the best activity and stability for the combustion of soot with oxygen. A reaction mechanism involving the redox sites and the surface-carbonate species takes place on these catalysts. On the other hand, Co,K/La2O3 and Co,K/CeO2 catalysts display activity for the simultaneous removal of soot and nitric oxide. The soot-catalyst contacting phenomenon was also addressed. A synergic La-K effect was observed in which the mechanical mixtures of soot with K-La2O3 showed higher combustion rates than those observed when K and La were directly deposited on the soot surface. The effect of the addition of Ba was explored with the aim of promoting the interaction of the solid with NO2, thus combining the NOx catalytic trap concept with the soot combustion for filter regeneration. Ba/CeO2 and Ba,K/CeO2 were effective in NOx absorption as shown in the microbalance experiments. However, the formation of stable nitrate species inhibits the soot combustion reaction. © 2002 Elsevier Science B.V. All rights reserved.Fil: Pisarello Milesi, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Peralta, María Ariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Querini, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Stacked wire mesh monoliths for the simultaneous abatement of VOCs and diesel soot

Structured catalysts based on Pt,CeO2 deposited on stainless steel wire meshes were developed to build catalytic cartridges for the treatment of diesel exhaust gases. The cartridges were tested for the simultaneous combustion of volatile organic compounds (VOCs) and soot. To this end, n-hexane, acetyl acetate, and toluene were selected as probe molecules. Each of them were loaded together with real soot into the cartridges showing that while VOCs abatement takes place between 200 °C and 350 °C, soot combustion occurs in the 300-500 °C temperature range with an average maximum combustion rate at 420 °C. The catalytic cartridges were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) techniques. The mechanical stability of the coatings was confirmed by the ultrasound method. Air permeability of the cartridges prepared with different mesh sizes was also measured and the results were correlated using the Payri equation.Fil: Godoy, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Banus, Ezequiel David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Sanz, Oihane. Universidad del País Vasco; EspañaFil: Montes Ramirez, Mario. Universidad del País Vasco; EspañaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Milt, Viviana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Temperature is a common climatic descriptor of lachryphagous activity period in Phortica variegata (Diptera: Drosophilidae) from multiple geographical locations

Background: The drosophilid Phortica variegata is known as vector of Thelazia callipaeda, the oriental eyeworm native to Asia that has become an emergent zoonotic agent in several European regions. Unlike almost all other arthropod vectors of pathogens, only P. variegata males feed of lachrymal secretions of animals, ingesting first-stage larvae (L1) of the worm living in the orbital cavities of the host, and allowing with the same behaviour the introduction of infective L3. Despite the increased detection of T. callipaeda in many European countries, information about the length of the lachryphagous activity period of P. variegata and a deep knowledge of the environmental and climatic variables involved are still limited. Methods: We herein present the results of a multicentre study involving five sites from four different countries (Italy, Spain, UK and USA) where canine thelaziosis is endemic and/or where it has already been ascertained the presence of P. variegata. Field data have been obtained on a fortnightly basis from mid-April to the end of November 2018 from a contemporary standardized sampling (same sampling effort and time of collection in all sites) of lachryphagous flies collected around the eyes of a human bait using an entomological net. These data have been associated to data collection of local climatic variables (day length, temperature, wind speed, barometric pressure and relative humidity). Results: Overall, a total of 4862 P. variegata flies (4637 males and 224 females) were collected, with high differences in densities among the different sampling sites. Significant positive correlations were found between P. variegata male density and temperature and wind speed, while negative correlations were observed for barometric pressure and relative humidity. However, the above significant differences are confirmed in each sampling site separately only for the temperature. Conclusions: This multicentre study highlights that temperature is the major common environmental driver in describing the lachryphagous activity of P. variegata in Europe and USA and, therefore, the transmission risk of thelaziosis.[Figure not available: see fulltext.