No description available.

Cerâmicas de zircônia estabilizada com ítria são utilizadas na forma densa como eletrólito e na forma porosa como ânodo em células a combustível de óxido sólido. Neste trabalho cerâmicas porosas de zircônia estabilizada com 8 mol% de ítria foram preparadas por meio da adição de diferentes teores de KI, NaCl e grafite como aditivo sacrificial. A remoção térmica do aditivo foi avaliada por meio de análises termogravimétrica, térmica diferencial e dilatométrica. As amostras foram preparadas por meio de mistura, compactação e sinterização a 1400 ºC/2 h. As amostras foram caracterizadas por difração de raios X(DRX) e análise topográfica em microscópio de varredura por sonda e microscópio eletrônico de varredura de superfícies polidas e atacadas para avaliação da distribuição do teor de poros e tamanho médio de grãos. O teor do aditivo residual foi avaliado por fluorescência de raios X (FRX). O comportamento elétrico foi analisado por espectroscopia de impedância (EI) na faixa de frequências 5 Hz-10 MHz entre 300 ºC e 450 ºC. Os resultados de FRX mostram que não há resíduo do aditivo após sinterização. A análise de DRX indica que todas as amostras têm fase única, cúbica tipo fluorita. Os diagramas de impedância mostram que há aumento i) das resistividades elétricas intergranular e intragranular, evidenciando a formação de poros em ambas as regiões, ii) do ângulo de descentralização do semicírculo a baixas frequências, devido ao aumento do grau de heterogeneidade pela presença de poros, e iii) do produto do fator de bloqueio R pelo fator de frequência f, consequência do aumento do teor de poros. Esses resultados estão em concordância com os resultados das análises de microscopia de varredura por sonda e de microscopia eletrônica de varredura. / Dense and porous yttria-stabilized zirconia ceramics are used as electrolytes and anodes, respectively, in solid oxide fuel cells. Porous ZrO2: 8 mol% Y2O3 (8YSZ) were prepared by using NaCl, KI and graphite as sacrificial additives. The thermal removal of the additives was evaluated by thermogravimetry, differential thermal analysis and dilatometry. The samples were prepared by thoroughly mixing 8YSZ to the additives, pressing and sintering at 1400 ºC/2 h. The samples were characterized by X-ray diffraction (XRD) and by observation of polished and etched surfaces in scanning probe microscope (SPM) and scanning electron microscope (FEG-SEM) to evaluate pore content. The evaluation of the NaCl and KI content was carried out by X-ray fluorescence (XRF) analysis. The electrical behavior was analyzed by impedance spectroscopy (IS) in the 5 Hz-10 MHz frequency range from 300 ºC to 450 ºC. The XRF results show no remaining KI or NaCl in the sintered samples. The XRD patterns show all samples are single cubic fluorite phase. The IS plots show that there is an increase i) of the intergranular and the intragranular electrical resistivity, an indication of bulk and grain boundary pore formation, ii) of the decentralization angle of the grain boundary semicircle in the impedance plots due to increasing heterogeneity of the samples, and iii) of the product of the blocking factor R to the frequency factor f, as a consequence of the increase in pore content. These results are in agreement with the SPM and SEM observations.

>Magister Scientiae - MSc / Inorganic based membranes which have a symmetric/asymmetric structure have been produced using an immersion induced phase inversion and sintering method. An organic binder solution (dope) containing yttria-stabilised zirconium (YSZ) particles is spun through a triple orifice spinneret to form a hollow fibre precursor, which is then sintered at elevated temperatures to form a ceramic support. The phase inversion process for the formation of hollow fibre membranes was studied in order to produce the best morphological structure/support for palladium based membranes. The spinning parameters, particle size, non-solvent concentration, internal coagulant as well as the calcination temperature were investigated in order to determine the optimum values. Sintering temperature was also investigated, which would yield a sponge-like structure with an optimized permeability, while retaining a smooth outer surface. The supports produced by phase inversion were characterized in terms of dimension by mercury porosimetry, compressed air permeability, Surface Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The morphology of the produced ceramic support showed either dense or porous characteristics governed by the dynamics of the phase inversion process. The particle size of YSZ was examined in order to decrease the amount of agglomerates in the spinning suspension. Zetasizer tests indicated that at 15 minutes, the ultrasonic bath effectively homogenised the YSZ particles and prohibited soft agglomerates from reforming in the spinning suspension. In this study, an increase in air gap had no noticeable effect on the finger like voids but it had a considerable effect on both the inner diameter (ID) and outer diameter (OD) of the green fibres, while an increase in bore liquid flow rate and extrusion pressure promoted viscous fingering and significant effect on the ID and OD of the fibres, respectively. There was a decrease in porosity and permeability with increasing sintering temperature, addition of water concentration in the spinning suspension and varying N-methylpyrrolidone (NMP) aqueous solution of the internal coagulant. The amount of YSZ added to the starting suspension influenced the properties of the support structure. Viscous deformation was observed for dope with lower particle loading thus resulted in the formation of cracks and defects during sintering.

Thermal Barrier Coatings (TBC) are used to shield hot sections of gas turbine engines, helping to prevent the melting of metallic surfaces. TBC is a sophisticated layered system that can be divided into top coat, bond coat, and the super-alloy substrate. The highly heterogeneous microstructure of the TBC consists of defects such as pores, voids, and cracks of different sizes, which determine the coating’s final thermal and mechanical properties. The service lives of the coatings are dependent on these parameters. These coatings act as a defensive shield to protect the substrate from oxidation and corrosion caused by elevated temperatures. Yttria Stabilized Zirconia (YSZ) is the preferred thermal barrier coating for gas turbine engine applications. There are a certain number of deposition techniques that are used to deposit the thermal coating layer on the substrate; commonly used techniques are Air Plasma Sprayed (APS) or Electron Beam Physical Vapour Deposition (EB-PVD). The objective of this thesis is to model an optimized TBC that can be used on next-generation turbine engines. Modelling is performed to calculate the effective thermal conductivity of the YSZ coating deposited by EB-PVD by considering the effect of defects, porosities, and cracks. Bruggeman’s asymmetrical model was chosen as it can be extended for various types of porosities present in the material. The model is used as an iterative approach of a two-phase model and is extended up to a five-phase model. The results offer important information about the influence of randomly oriented defects on the overall thermal conductivity. The modelled microstructure can be fabricated with similar composition to have an enhanced thermal insulation. The modelling results are subsequently compared with existing theories published in previous works and experiments. The modelling approach developed in this work could be used as a tool to design the porous microstructure of a coating.

<div>Yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs) provide thermal and environmental protection to superalloy components operating within the combustor and high pressure sections of a gas turbine. However, calcium-magnesium-aluminum silicate (CMAS) deposits originated from particulate matter ingested through the air intake degrade YSZ TBCs, ultimately decreasing the overall efficiency of the engines. With the introduction of biofuels into gas turbines, a new list of impurities with no precedent in jet engines may interact with TBCs, arising the possibility to form CMAS deposits without flying in a particular environment and to exacerbate CMAS negative effect through the addition of other contaminants.</div><div><br></div><div>In this work, a cyclic thermal gradient rig was developed to test TBCs in similar conditions as in a gas turbine. The heat flux and non-contact surface temperature measurements were validated with a thermal transient model. The effect of biofuel impurities on YSZ TBCs was evaluated by spraying the coatings with impurity cocktails, solutions containing the impurities of interest, and subsequently testing their lifetimes in the ablation rig.</div><div><br></div><div>Detailed microstructure analysis revealed that APS and EB-PVD TBCs fail in different ways when exposed to equal concentrations of CMAS. When contaminating APS TBCs with varying combinations of CMAS constituents (e.g., S, C-S, C-A, C-A-S, C-M-S, and C-M-A-S), it was possible to identify that coatings delaminated at different rates depending on the combination of CMAS constituents. Finally, the effect of CMAS in combination with contaminants exclusive of biofuels was analyzed on YSZ TBCs. X-ray diffraction (XRD) analysis and micrographs revealed that glass modifiers (e.g., K₂O and ZnO) accelerated the degradation of YSZ TBCs.</div>

Yttria stabilized zirconia (YSZ) is a polymorph with possible phase transformation toughening occurring during impact. The fractography and mechanical properties of laminated alumina and YSZ were studied in this thesis. Five sample types were studied in this thesis: (5:5) Al2O3/YSZ (a sequence of 5 alumina tapes stacked on 5 YSZ tapes), (5:5) Al2O3/YSZ (1 wt.% Pure ZrO2), (7:3) Al2O3/YSZ, Al2O3, and YSZ. Scanning electron microscopy (SEM) and X-ray microscopy (XRM) were used to study morphology and crack propagation with three-point tests performed to study the flexural strength. X-ray diffraction (XRD) spectra of all samples pre and post three-point tests were examined to determine if a change in monoclinic zirconia occurred. The combination of SEM and XRM data found microcracks in the YSZ layers of Al2O3/YSZ laminates with none present on YSZ laminates, leading to the conclusion tensile stress was performed on YSZ during sintering with Al2O3. Fracture patterns show a curving of cracks in Al2O3 layers and abrupt, jagged breaks in YSZ layers with crack forking at major YSZ microcrack regions. YSZ laminates were found to have the highest average flexural strength, but a very high standard deviation and low sample count and Al2O3 laminates having the second highest flexural strength. The (7:3) Al2O3/YSZ laminates had a significant increase in flexural strength compared to both types of (5:5) Al2O3/YSZ laminates. Significant change in monoclinic presence was not found except for the (5:5) Al2O3/YSZ (1 wt.% Pure ZrO2) laminates.

No description available.

En la presente tesis doctoral se han desarrollado dispositivos electroquímicos de estado sólido para la detección selectiva de hidrocarburos en los gases de escape de coches. Diversos materiales fueron empleados para ello. También se llevó a cabo la activación catalítica del electrodo de trabajo para mejorar la reacción electroquímica del analito objetivo. El etileno fue seleccionado como el analito objetivo para cuantificar la cantidad total de hidrocarburos ya que es uno de los hidrocarburos más abundantes en un gas de escape. Pero el dispositivo no solo debe proporcionar una respuesta selectiva al etileno, sino que también debe tener una baja sensibilidad cruzada a otros compuestos también abundantes en un gas de escape como monóxido de carbono, agua, dióxido de nitrógeno, etc. El dispositivo consiste en un sensor potenciométrico de estado sólido en el que óxido de zirconio estabilizado con 8% de óxido de itrio (8YSZ) es empleado como electrolito. Dos electrodos son impresos en la superficie de cada cara. Primero, diversos óxidos fueron empleados como electrodo de trabajo utilizando a su vez platino como electrodo de referencia a 550ºC. Muchos de los materiales fueron descartados por su falta de selectividad al etileno, su alta sensibilidad cruzada al monóxido de carbono o por su respuesta no estable. Finalmente, Fe0.7Cr1.3O3 mezclado con 8YSZ fue seleccionado como el material más prometedor dada su buena selectividad al etileno con baja sensibilidad cruzada al monóxido de carbono. Esta configuración fue expuesta a agua como a fenantreno y metilnaftaleno. Esto produjo un aumento de la sensibilidad cruzada del dispositivo al monóxido de carbono, motivo por el que el sensor no sea adecuado para los objetivos de esta tesis. La estrategia adoptada consistió en actuar sobre el electrodo de referencia. El Platino, empleado habitualmente en la bibliografía como electrodo de referencia, fue cambiado por un conductor mixto iónico-electrónico activo al oxigeno: La0.8Sr0.2MnO3 mezclado con 8YSZ (LSM/8YSZ). Desgraciadamente, esto provocó un aumento de la sensibilidad cruzada al monóxido de carbono. Diversas nanopartículas fueron añadidas en el electrodo de trabajo para mejorar la actividad catalítica y aumentar la reacción electroquímica al etileno. Níquel, titanio y aluminio (especialmente la combinación de los dos últimos con níquel) dieron la mejor respuesta: el sensor era selectivo al etileno con baja sensibilidad cruzada al monóxido de carbono, agua y fenantreno. El efecto del espesor del electrolito en la respuesta del sensor también fue evaluado en un rango de 0.1 a 1.2 mm. Aunque no había una gran diferencia en la respuesta, la sensibilidad cruzada al monóxido de carbono era menor en el caso del dispositivo más fino. Otras alternativas al 8YSZ como electrolito también fueron evaluadas para trabajar a menores temperaturas (400 a 550ºC): oxido de cerio dopado con gadolinio (CGO) y óxido de zirconio estabilizado con un 10% de óxido de escandio (ScSZ). El dispositivo basado en ScSZ mostró un buen comportamiento a etileno a bajas temperaturas y en condiciones secas pero la adición de agua provocaba un aumento de la sensibilidad cruzada al monóxido de carbono. Una vez infiltrado el electrodo de trabajo con níquel, ambos dispositivos mostraron un buen comportamiento a bajas temperaturas en condiciones secas para concentraciones de etileno inferiores a 100 ppm, aunque la mejor respuesta fue obtenida a 550ºC. Ambos dispositivos mostraron una respuesta selectiva al etileno con baja sensibilidad cruzada al monóxido de carbono, agua y fenantreno. Se estudió también el efecto de mezclar el electrodo de trabajo con un conductor iónico (8YSZ). Se mezcló La0.87Sr0.13CrO3 (LSC) con 8YSZ sin observarse un cambio en la respuesta comparado con el electrodo solo. Además la mejor configuración Fe0.7Cr1.3O3/8YSZ//8YSZ//LSM/8YSZ (infiltrado con níquel) fue expuesto a dioxide de nitr / The present thesis is focused on the development of solid-state electrochemical devices for the selective detection of hydrocarbons in car exhaust gases. For this purpose, several materials were tested as electrodes and electrolytes. Catalytic activation of the working electrode has also been taken into account to boost the electrochemical reaction of the target analyte. Ethylene is one of the most abundant hydrocarbons in an exhaust gas and was selected as the target analyte to quantify the total amount of hydrocarbons. Not only the device has to be selective to ethylene but it must also have a low cross-sensitivity toward other pollutants abundant in an exhaust gas such as carbon monoxide, water, other hydrocarbons, nitrogen dioxide, etc. Thus, a solid-state potentiometric sensor was selected based on 8% Ytria-stabilized Zirconia (8YSZ) as electrolyte. Two electrodes were screen-printed on top of each face. First, several metal oxides were tested as working electrode with platinum (Pt) as reference electrode at 550ºC. Most of the materials were discarded because of their lack of selectivity to ethylene, high cross-sensitivity toward carbon monoxide or problems regarding stability. Fe0.7Cr1.3O3 mixed with 8YSZ was finally selected as the most promising material because of its selective response to ethylene with relatively low cross-sensitivity toward carbon monoxide. This sensor configuration was then exposed to water and phenanthrene and methylnaphthalene. This led to an increase of the cross-sensitivity of the device toward carbon monoxide making the device not suitable for the purposes of the present thesis. The approach to improve the sensor performance was to modify the reference electrode. Platinum, usually employed in literature as reference electrode, was exchanged for a mixed ionic-electronic conductor active to oxygen: La0.8Sr0.2MnO3 mixed with 8YSZ (LSM/8YSZ). Unfortunately, this increases the device activity toward carbon monoxide increasing its cross-sensitivity. Several nanoparticles were added onto the working electrode to improve the catalytic activity and boost the electrochemical reaction of ethylene. Nickel, titanium and aluminum (the last two elements combined with nickel) provided the best performance: selectivity to ethylene with low cross-sensitivity toward carbon monoxide, water and phenanthrene. The effect of the electrolyte thickness was also checked in the range from 0.1 to 1.2 mm. Although there was not a huge difference between them, the cross-sensitivity toward carbon monoxide was slightly lower for the thinnest sensor. Other alternatives to 8YSZ electrolyte were tested at lower working temperatures (400 to 550ºC) with the same electrodes materials: gadolinium-doped cerium oxide (CGO) and 10% scandia-stabilized Zirconia (ScSZ). ScsZ-based device showed a good performance in dry conditions but the addition of water decreased its suitability. Once improved the catalytic activity of the working electrode, both devices showed a good performance at lower temperature in dry conditions for ethylene concentration above 100 ppm but the best response was achieved at 550ºC. Both devices were selective to ethylene with low cross-sensitivity toward carbon monoxide, water and phenanthrene. The effect of mixing the working electrode with an ionic conductor (8YSZ) was also tested by mixing La0.87Sr0.13CrO3 (LSC) with 8YSZ and no change in response was observed when compared to the bare electrode. Finally, the best sensor configuration Fe0.7Cr1.3O3/8YSZ//8YSZ//LSM/8YSZ (after infiltration with nickel) was exposed to nitrogen dioxide to check the cross-sensitivity. The response was still selective to ethylene even with the addition of nitrogen dioxide plus water. / En la present tesi doctoral s'han desenvolupat dispositius electroquímics d'estat sòlid per a la detecció selectiva d' hidrocarburs als gasos d'escapament dels automòbils. Diversos materials van ser empleats per a tal fi. També es va dur a terme l'activació catalítica de l'elèctrode de treball per a millorar la reacció electroquímica al anàlit objectiu. L' etilè va ser seleccionat com anàlit objectiu per a quantificar la quantitat total d' hidrocarburs, ja que és un dels hidrocarburs més abundants en un gas d'escapament. Però el dispositiu no ha de ser tan sols selectiu a l'etilè, sinó que també deu proporcionar una baixa sensibilitat creuada a altres elements força abundants en un gas d'escapament com són el monòxid de carboni, l'aigua, el diòxid de nitrogen, etc. Així, el dispositiu consisteix en un sensor potenciomètric d'estat sòlid en el que l'òxid de zirconi estabilitzat amb un 8% d'òxid d'itri (8YSZ) és empleat como a electròlit. Els elèctrodes van impresos a cadascuna de les superfícies del dispositiu. Primer, diversos òxids es van emprar com a elèctrode de treball fent servir platí com elèctrode de referència a 550ºC. Molts dels materials van ser descartats per motiu de la seva manca de selectivitat al etilè, la seva alta sensibilitat creuada al monòxid de carboni o perquè la resposta no era estable. Finalment, el Fe0.7Cr1.3O3 mesclat amb 8YSZ va ser seleccionat com el material més prometedor atès a la selectivitat a l'etilè i la baixa sensibilitat creuada al monòxid de carboni. Aquesta configuració és doncs exposada tant a l'aigua com al fenantrè i al metilnaftalè. Això va produir un increment de la sensibilitat creuada al monòxid de carboni, fent que el dispositiu no resulti idoni per als objectius de la present tesi. Es va adoptar com a estratègia modificar l'elèctrode de referència. Platí, empleat sovintment com a elèctrode de referència a la bibliografia, va ser canviat per un conductor mixt iònic-electrònic actiu a l'oxigen: La0.8Sr0.2MnO3 mesclat amb 8YSZ (LSM/8YSZ). Malauradament, això va provocar l'augment de la sensibilitat creuada al monòxid de carboni. Diverses nanopartícules van ser afegides al elèctrode de treball per tal de millorar la seva activitat catalítica i així augmentar la reacció electroquímica de l'etilè. Níquel, titani i alumini (especialment la combinació dels dos darrers amb níquel) van donar la millor resposta: el sensor era selectiu a l¿etilè amb una baixa sensibilitat creuada al monòxid de carboni, l'aigua i al fenantrè. L'efecte del espessor del electròlit a la resposta del sensor també va ser avaluada en un rang de 0.1 a 1.2 mm. Malgrat que no hi ha una gran diferència en la resposta, la sensibilitat creuada al monòxid de carboni és menor en el cas del dispositiu més prim. Altres alternatives al 8YSZ com a electròlit van ser també avaluades per tal de treballar a temperatures menors (400 a 550ºC): òxid de ceri dopat amb gadolini (CGO) i òxid de zirconi estabilitzat amb un 10% d'òxid d'escandi (ScSZ). El dispositiu basat en ScSZ va mostrar un bon comportament a l'etilè a baixes temperatures en condiciones seques, però la adició d'aigua provocava un augment de la sensibilitat creuada al monòxid de carboni. Una vegada que l'elèctrode de treball es infiltrat amb níquel, ambdós dispositius mostraren un bon comportament a baixes temperatures en condicions seques per a concentracions d'etilè menors de 100 ppm, encara que la millor resposta fou obtinguda a 550ºC. La resposta era selectiva a l'etilè amb una baixa sensibilitat creuada al monòxid de carboni, l'aigua i el fenantrè. Es va comprovar també l'efecte de mesclar l'elèctrode de treball amb un conductor iònic (8YSZ). Es va mesclar La0.87Sr0.13CrO3 (LSC) amb 8YSZ sense observa cap canví en la resposta comparada amb l'electrode sense 8YSZ. la millor configuració Fe0.7Cr1.3O3/8YSZ//8YSZ//LSM/8YSZ (infiltrado con níquel) fou exposada / Toldra Reig, F. (2018). Development of electrochemical devices for hydrocarbon sensing purposes in car exhaust gases [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/110968

Une des solutions envisagée pour éviter la réactivité entre la cathode de LSCF et l'électrolyte de YSZ est l'intercalation d'une couche barrière de CGO. Une étude de la réactivité interfaciale par DRX et ToF-SIMS entre CGO, déposée par atomisation électrostatique, et YSZ a montré qu'un traitement thermique au-dessus de 1100 C sous air induit une détérioration de la couche de CGO par la formation d'une solution solide. Le vieillissement du système LSCF/CGO/YSZ a été étudié en fonction de l'épaisseur de la couche de CGO de 0,11 à 2 µm, par spectroscopie d'impédance complexe, à 700 °C sous air à l'abandon. Les mesures ont montré que l'épaisseur de cette couche est un facteur influençant les propriétés électriques des différents systèmes. L'introduction d'une couche mince de CGO, déposée par pulvérisation cathodique, a conduit à une diminution de la résistance série du système ainsi qu'une diminution de la dégradation de l'électrode LSCF. La dégradation de l'électrode de LSCF est liée à la ségrégation du Sr au niveau de l'interface LSCF/YSZ. / One of the considered solutions to avoid the reactivity between LSCF cathode and YSZ electrolyte is the intercalation of a CGO buffer layer. A study of the interfacial reactivity by XRD and by ToF-SIMS between CGO, by ESD, and YSZ has shown that an heat treatment above 1100 °C in air leads to the chemical degradation of the CGO layer leads to the formation of a solid solution. An ageing investigation of LSCF/CGO/YSZ half cell was performed for different CGO layer thicknesses coated by DC magnetron sputtering from 0.11 to 2 µm, by electrochemical impedance spectroscopy at 700 °C in air at OCV. EIS measurements have shown that the thickness of this coating has a strong effect on the electrical properties of these systems. The introduction of a thin CGO buffer layer has lead to the decrease of the initial value of the series resistance and to the reduction of the LSCF electrode degradation. This degradation electrode is due to the diffusion of Sr at the LSCF/YSZ interface as shown by microanalyses X.

Les travaux s'inscrivent dans le développement de catalyseurs conducteurs ioniques à base de zircone stabilisée à l'oxyde d'yttrium (YSZ) pour l'oxydation des suies dans les filtres à particules (FAP) qui équipent les véhicules Diesel. L'oxydation de la suie sur YSZ a été observée à l'échelle nanométrique par microscopie électronique en transmission environnementale. La réaction d'oxydation se déroule à l'interface (20-40 nm) entre le catalyseur et la suie, l'activité étant liée au nombre de points de contact. Nous avons associé un vecteur d'oxygène mobile, l'argent, à YSZ. Les résultats montrent une synergie entre YSZ et les nanoparticules d'argent qui promeut l'activité notamment en cas de contact grossier avec la suie. Des expériences isotopiques d'échanges et d'oxydation ont démontré que l'argent active l'intégration de l'oxygène gazeux dans le réseau de YSZ. La caractérisation des propriétés physicochimiques des nanoparticules d'argent dispersées sur différents oxydes (une autre zircone yttriée aux propriétés différentes : YSZb, ZrO2, CeZrO2, SiO2) a permis de relier les performances catalytiques avec la teneur d'argent métallique en surface. Des tests de vieillissement hydrothermal ont montré que la formulation supportée sur YSZb présente une activité maintenue en contact médiocre avec la suie et une faible perte en argent. Des mini-FAPs imprégnés de catalyseur ont ensuite été testés sur un banc de gaz synthétiques capable de produire des particules de suie en suspension. L'activité des formulations catalytiques une fois mises en forme ainsi que leur capacité de filtration ont été évaluées. Un mini-FAP contenant la formulation Ag/YSZb oxyde les suies dès 350°C et s'auto-régénère (oxydation des suies plus rapide que leur collecte) dès 450°C / This study deals with the development of ionic conductive catalysts based on yttria-stabilized zirconia for soot oxidation in Diesel Particle Filter (DPF). Soot oxidation was observed at the nanoscale using Environmental Transmission Electron Microscopy. Reaction was shown to occur at the interface between YSZ and soot, ranging from 20 to 40 nm, and activity was related to the number of contact points between soot and catalyst. In order to promote activity, we associated to YSZ an oxygen carrier: silver, under the form of silver nanoparticles (AgNPs) scattered over YSZ surface. Results display a synergy between YSZ and AgNPs, allowing for the promotion of soot oxidation under poor contact conditions. Isotopic exchange and oxidation experiments demonstrated AgNPs promote oxygen integration into YSZ lattice. Characterizations of supported AgNPs over different oxides such as YSZb (displaying different properties than YSZ), ZrO2, SiO2, CeZrO2, indicate that the soot oxidation activity is related to the amount of metallic silver species on the oxide surface. Hydrothermal ageing tests indicate that Ag/YSZb formulation displays a stable activity in poor contact conditions and a low silver loss. Baby-DPF (1 inch diameter, 3 inches length) were impregnated with silver-supported catalysts and tested on a synthetic gas bench producing a gas stream containing suspended soot particles. Soot oxidation activity and filtration efficiency were measured. A baby-FAP containing the Ag/YSZb formulation was shown to oxide soot at a temperature as low as 350°C and to induce self-regeneration (soot oxidation overcoming the collection) at 450°C