Μελετήθηκε η αντίδραση αναμόρφωσης της αιθανόλης με ατμό προς παραγωγή υδρογόνου για την τροφοδοσία στοιχείων καυσίμου. Η παραγωγή υδρογόνου από αιθανόλη, αποτελεί ελκυστική διεργασία τόσο από οικονομική, όσο και από περιβαλλοντική άποψη. Το παραγόμενο υδρογόνο μπορεί να χρησιμοποιηθεί σε στοιχεία καυσίμου ως ρεύμα τροφοδοσίας, όπου οξειδώνεται ηλεκτροχημικά παρουσία αέρα αποδίδοντας ηλεκτρική ενέργεια και θερμότητα με μοναδικό προϊόν καύσης το νερό. Η αντίδραση αναμόρφωσης της αιθανόλης με ατμό είναι θερμοδυναμικά εφικτή και η αύξηση της θερμοκρασίας οδηγεί σε αυξημένη απόδοση σε υδρογόνο. Η συνολική διεργασία παραγωγής υδρογόνου από ατμοαναμόρφωση της αιθανόλης έχει υψηλότερη θεωρητική απόδοση από την ατμοαναμόρφωση του μεθανίου, η οποία είναι η κύρια διεργασία παραγωγής υδρογόνου σήμερα. Οι μελέτες της αντίδρασης αναμόρφωσης της αιθανόλης με ατμό σε καταλύτες κοβαλτίου, ευγενών μετάλλων και νικελίου, έδειξαν ότι οι βέλτιστοι καταλύτες της διεργασίας είναι οι 2% Rh/Al2O3, 5% Ru/Al2O3 και 17% Ni/(La2O3/Al2O3). Οι καταλύτες νικελίου εναποτεθειμένοι σε γ-Al2O3, La2O3 και La2O3/Al2O3 μελετήθηκαν προκειμένου να διερευνηθεί το δίκτυο των αντιδράσεων της αιθανόλης με τον ατμό με χρήση δυναμικών τεχνικών και τεχνικών μόνιμης κατάστασης. Προσεγγίστηκε το δίκτυο αντιδράσεων και τιτλοδοτήθηκε ο εναποτεθειμένος άνθρακας. Αναπτύχθηκαν κεραμικοί και μεταλλικοί θερμικά ολοκληρωμένοι αντιδραστήρες αναμόρφωσης της αιθανόλης με ατμό. Η πραγματοποίηση των αντιδράσεων αναμόρφωσης και καύσης στον κεραμικό αντιδραστήρα οδήγησε σε ικανοποιητική απόδοση. Παράλληλα, διεξήχθησαν πειράματα αναμόρφωσης και καύσης της αιθανόλης στο μεταλλικό αντιδραστήρα με χρήση καταλυτικών κλινών. Τα πειράματα αναμόρφωσης - καύσης απέδειξαν τη λειτουργικότητα του συστήματος, ενώ η σχετική θέση των καταλυτικών κλινών διαπιστώθηκε ότι αποτελεί σημαντικό παράγοντα στην απόδοση του αντιδραστήρα. Τέλος, αναπτύχθηκαν καινοτόμοι μέθοδοι εναπόθεσης καταλυτικών στρωμάτων στις επιφάνειες μεταλλικών σωλήνων. Στην εξωτερική επιφάνεια εναποτέθηκε αλούμινα ως υπόστρωμα για τον καταλύτη αναμόρφωσης με ψεκασμό πλάσματος, ενώ στο εσωτερικό του σωλήνα χρησιμοποιήθηκε μέθοδος εναπόθεσης αλουμινίου για τη δημιουργία του απαιτούμενου συγκολλητικού υποστρώματος. Οι καταλύτες που παρήχθησαν είχαν υψηλή αντοχή σε θερμικούς κύκλους και μεγάλη απόδοση στην αντίδραση αναμόρφωσης. / Production of hydrogen from steam reforming of ethanol is examined for application in fuel cells. The production of hydrogen from ethanol is an attractive operation from economical as well as from environmental point of view. The produced hydrogen can be fed to fuel cells, undergoing oxidation and producing electric energy and heat with the only combustion product being water. Steam reforming of ethanol is thermodynamically feasible and high temperatures result in high efficiency towards hydrogen production. The overall thermal efficiency of the operation is calculated and proven to be higher than the respective value of steam reforming of methane, which is the main commercial hydrogen producing operation. Steam reforming of ethanol was studied with catalysts based on Co, noble metals and Ni. The most promising materials were found to be the 2% Rh/Al2O3, 5% Ru/Al2O3 and 17% Ni/(La2O3/Al2O3) catalysts. The reaction network of steam reforming of ethanol, as well as carbon deposition, over nickel catalysts supported on γ-Αl2O3, La2O3 and La2O3/γ-Al2O3 is investigated employing transient and steady state techniques. Ceramic and metallic heat integrated reactors were developed for the reaction of steam reforming of ethanol. Experiments of coupled combustion – reformation in the ceramic reactor resulted in increased efficiency. In addition, experiments of coupled combustion – reformation were carried out in a metallic reactor by use of catalytic beds. The combustion-reformation experiments proved the effectiveness of the reactor, while the relative position of the two catalytic beds plays important role in the efficiency of the reactor. Finally, novel methods of catalyst deposition over metallic tubes were developed. On the outer surface an intermediate film of aluminum oxide was deposited by means of thermal plasma spraying in order to support the catalyst. Over the inner surface of the tube, aluminum powder was deposited and thermally processed to produce the necessary intermediate substrate. The materials produced by the above mentioned methods, were rigid and stable under extreme thermal-cycles, additionally the reforming material exhibited high efficiency.

The objective of the thesis was to analyze the ageing processes and the modifications of an Ir/CeO2catalyst for steam reforming of ethanol. Over a model Ir/CeO2 catalyst, the initial and fast deactivationwas ascribed to ceria surface restructuring and the build-up of intermediates monolayer (acetate,carbonate and hydroxyl groups). In parallel, a progressive and slow deactivation was found to come fromthe structural changes at the ceria/Ir interface linked to Ir sintering and ceria restructuring. Theencapsulating carbon, coming from C2 intermediates polymerization, did not seem too detrimental to theactivity in the investigated operating conditions. By doping ceria with PrOx, the oxygen storage capacityand thermal stability were greatly promoted, resulting in the enhanced activity and stability. The Ir/CeO2catalyst was then modified by changing the shape of ceria. It was found that the shape and therefore thestructure of ceria influenced the activity and stability significantly. A simplified modeling of theseprocesses has contributed to support the new proposals of this work.

This work focuses on methane and ethanol conversion to hydrogen in the presence of a catalyst in order to increase the selectivity of the desired product (H₂) and reduce carbon monoxide emission and coke formation. Two kinds of active phase were used (copper and ruthenium) and impregnated on calcined hydrotalcites CoₓMg₆₋ₓAl₂ in order to be evaluated in the methane and ethanol steam reforming reactions. For both reactions, the influence of several factors was evaluated in order to adjust the reaction parameters. It has been shown that catalysts performances for the reforming reactions depend on the content of cobalt and magnesium. High cobalt content enhanced the catalytic activity. 1Ru/Co₆Al₂ catalyst presented the highest activity and stability in the methane steam reforming reaction among the other industrial and prepared catalysts even under a low GHSV and with no hydrogen pretreatment. Reduced ruthenium and cobalt were detected after the reaction by XRD. EPR technique was able to detect negligible amount of two kinds of carbonaceous species formed during the reaction : coke and carbon. On the other hand, 5Cu/Co₆Al₂ catalyst revealed the highest hydrogen productivity in the ethanol steam reforming reaction. However, it suffers from coke formation that deactivated the catalysts after few hours. 5Cu/Co₂Mg₄Al₂ catalyst showed a much lower quantity of carbonaceous species with no deactivating during 50 hours due to the basic character of the magnesium oxide phase present in the support.

Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-05T14:07:37Z No. of bitstreams: 2 Dissertação - Alécia Maria Golçalves - 2011.pdf: 3110848 bytes, checksum: 0b6c29c9a2a058e2fd9e9c31230c02a6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-05T16:24:15Z (GMT) No. of bitstreams: 2 Dissertação - Alécia Maria Golçalves - 2011.pdf: 3110848 bytes, checksum: 0b6c29c9a2a058e2fd9e9c31230c02a6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-05T16:24:15Z (GMT). No. of bitstreams: 2 Dissertação - Alécia Maria Golçalves - 2011.pdf: 3110848 bytes, checksum: 0b6c29c9a2a058e2fd9e9c31230c02a6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2011-09-12 / The reaction of steam reforming of ethanol is a way produce hydrogen gas, but it is essential to use catalysts to facilitate this reaction. This paper proposes the preparation of nanostructured catalysts impregnated with titanium oxide nanoparticles of cobalt and/or magnesium oxide. From the results of XRD, TEM and BET titanium oxide (anatase - T) obtained from the sol-gel method showed particles with crystallite size of 5-8 nm and a specific surface area of 258 m2g-1. The sodium titanate nanotubes were synthesized by alkaline hydrothermal treatment of titanium oxide in anatase phase, commercial (NT) and synthesized (NTS), resulting in nanotubes with outer diameter from 10 to 30 nm and length of 45 to 110 nm. The impregnation process of the oxides of cobalt and/or magnesium did not cause structural changes in the supports, and present level of metal below the desired level. Profiles of temperature programmed reduction showed the presence of cobalt oxide in the impregnated catalysts. The catalysts evaluated in the reaction of reforming ethanol (Co3O4, NT, NTCo, NTMgCo, and NTMgCo700 NTSMgCo) had ethanol conversion close to 100%, and the catalysts NTSMgCo, NTMgCo700 showed higher selectivity to 87.8% and 89,2%, respectively. With the exception of NT and NTCo catalysts showed no formation of ethylene. The amount of carbon after the catalytic tests ranged from 3.4 to 12.9 (%m/m/h). / A reação de reforma a vapor do etanol é uma forma de produzir o gás hidrogênio, porém é imprescindível a utilização de catalisadores para viabilizar esta reação. Este trabalho propõe catalisadores nanoestruturados de titânio impregnado com nanopartículas de óxido de cobalto e/ou óxido de magnésio. A partir dos resultados de DRX e MET e BET o TiO2 - anatásio obtido a partir do método sol-gel apresentou nanopartículas com tamanho de cristalitos de 5 - 8nm e uma área superficial específica de 258m2g-1. Os nanotubos de titanatos de sódio foram sintetizados por tratamento hidrotérmico alcalino de óxidos de titânio - anatásio com tamanhos de partículas diferentes, apresentaram diâmetro externo de 10 - 30nm e comprimento de 45 - 110 nm. As curvas termogravimétricas mostraram que a decomposição térmica está relacionada à eliminação de água. O processo de impregnação dos diferentes óxidos de cobalto e/ou magnésio apresentou teores menores que o desejado e não proveram alterações estruturais nos nanotubos. O RTP do Co3O4 apresentou três bandas de redução, com máximos em 445, 550 e 660 °C e estas bandas também foram identificadas nos catalisadores impregnados com Co3O4. Os catalisadores Co, NT, NTCo, NTMgCo, NTMgCo700 e NTSMgCo apresentaram conversão do etanol próximo a 100%, sendo que os catalisadores NTSMgCo, NTMgCo700 apresentaram maior seletividade a H2 87,8% e 89,2%, respectivamente, e NTMgCo apresentou seletividade a H2 81,4 % e não formou acetaldeído. Após os testes catalíticos foram observados a deposição de carbono, variando 10 – 53%.

Ce travail a porté sur la conversion du méthane et de l'éthanol en hydrogène par le procédé du vaporeformage en utilisant de nouvelles formulations de catalyseurs afin d'augmenter la sélectivité en produit désiré (hydrogène), de réduire la production du monoxyde de carbone (Co) et défavoriser la formation de coke. Deux familles de phases actives, à base de cuivre et de ruthénium supportés par les hydrotalcites calcinées CoₓMg₆₋ₓAl₂, ont été évaluées dans ces réactions. Pour les deux réactions, l'influence de plusieurs facteurs a été évaluée afin d'ajuster les paramètres de la réaction. Il a été démontré que les performances des catalyseurs pour les réactions du vaporeformage dépendent de la teneur en cobalt et en magnésium.Une grande teneur en cobalt améliore la réactivité catalytique. Le catalyseur 1Ru/Co₆Al₂ a présenté la plus forte activité et stabilité dans la réaction du vaporeformage du méthane parmi les autres catalyseurs industriels et préparés. Les espèces réduites de ruthénium et du cobalt ont été détectées après la réaction par DRX. La technique RPE était capable de détecter des quantités négligeables de deux types d'espèces carbonées formées lors de la réaction : du coke et du carbone. D'autre part, le catalyseur 5Cu/Co₆Al₂ a révélé la productivité la plus élevée en hydrogène dans la réaction du vaporeformage de l'éthanol. Cependant, il se désactive après quelques heures à cause de la formation du coke. Le catalyseur 5Cu/Co₂Mg₄Al₂ a montré une quantité beaucoup plus faible d'espèces carbonées sans désactiver pendant 50 heures en raison du caractère basique de la phase de l'oxyde du magnésium présente dans le support. / This work focuses on methane and ethanol conversion to hydrogen in the presence of a catalyst in order to increase the selectivity of the desired product (H₂) and reduce carbon monoxide emission and coke formation. Two kinds of active phase were used (copper and ruthenium) and impregnated on calcined hydrotalcites CoₓMg₆₋ₓAl₂ in order to be evaluated in the methane and ethanol steam reforming reactions. For both reactions, the influence of several factors was evaluated in order to adjust the reaction parameters. It has been shown that catalysts performances for the reforming reactions depend on the content of cobalt and magnesium. High cobalt content enhanced the catalytic activity. 1Ru/Co₆Al₂ catalyst presented the highest activity and stability in the methane steam reforming reaction among the other industrial and prepared catalysts even under a low GHSV and with no hydrogen pretreatment. Reduced ruthenium and cobalt were detected after the reaction by XRD. EPR technique was able to detect negligible amount of two kinds of carbonaceous species formed during the reaction : coke and carbon. On the other hand, 5Cu/Co₆Al₂ catalyst revealed the highest hydrogen productivity in the ethanol steam reforming reaction. However, it suffers from coke formation that deactivated the catalysts after few hours. 5Cu/Co₂Mg₄Al₂ catalyst showed a much lower quantity of carbonaceous species with no deactivating during 50 hours due to the basic character of the magnesium oxide phase present in the support.

Ce travail rapporte l’étude des processus de désactivation et des modifications d’un catalyseur Ir supportésur cérine en vaporeformage de l’éthanol. Différentes causes de désactivation ont été identifiées selon lesconditions opératoires : température, temps de contact et temps de réaction. La désactivation initiale,rapide mais limitée a été attribuée à la restructuration de surface de la cérine et à la formation d’unemonocouche d’intermédiaires de type acetate, carbonate et hydroxyls. En parallèle, une désactivationlente et progressive a été mise en évidence, ayant pour origine les changements structurels de l’interfaceentre la cérine et l’iridium, liés au frittage des particules d’iridium et à la restructuration profonde de lacérine. Par contre, la formation continue, à température modérée, d’une couche de carbone encapsulantissu de la polymérisation d’intermédiaires C2 n’a pas semblé contribuer significativement à ladésactivation du catalyseur dans nos conditions opératoires. Pour limiter ce phénomène de désactivation,des modifications ont été apportées au catalyseur. Le dopage du catalyseur par PrOx a permis defortement améliorer la capacité de stockage de l’oxygène et la stabilité thermique du catalyseur,entraînant une augmentation de son activité et de sa stabilité en vaporeformage de l’éthanol. Lecatalyseur Ir/CeO2 a ensuite subi une mise en forme de la cérine (nano-tubes), avec une influencesignificative sur l'activité et la stabilité en vaporeformage de l’éthanol, liée à des effets structuraux. Unemodélisation simplifiée de ces divers phénomènes a également contribué à soutenir les propositionsoriginales de ce travail. / The objective of the thesis was to analyze the ageing processes and the modifications of an Ir/CeO2catalyst for steam reforming of ethanol. Over a model Ir/CeO2 catalyst, the initial and fast deactivationwas ascribed to ceria surface restructuring and the build-up of intermediates monolayer (acetate,carbonate and hydroxyl groups). In parallel, a progressive and slow deactivation was found to come fromthe structural changes at the ceria/Ir interface linked to Ir sintering and ceria restructuring. Theencapsulating carbon, coming from C2 intermediates polymerization, did not seem too detrimental to theactivity in the investigated operating conditions. By doping ceria with PrOx, the oxygen storage capacityand thermal stability were greatly promoted, resulting in the enhanced activity and stability. The Ir/CeO2catalyst was then modified by changing the shape of ceria. It was found that the shape and therefore thestructure of ceria influenced the activity and stability significantly. A simplified modeling of theseprocesses has contributed to support the new proposals of this work.

Os materiais nanoestruturados vêm sendo extensivamente estudados, não somente pelas novas propriedades e suas possíveis aplicações tecnológicas, mas também pela busca de uma melhor compreensão dos aspectos físicos e químicos causados por suas reduzidas dimensões. A céria (CeO2) tem despertado grande interesse nas últimas décadas, pois tem papel vital em tecnologias emergentes para aplicações em setores que vão desde a área ambiental através do desenvolvimento de novos catalisadores, passando pela área energética com o desenvolvimento de células de combustível em estado sólido e em novas tecnologias como a spintrônica por meio do desenvolvimento de novos materiais, os óxidos magnéticos diluídos. As propriedades físico-químicas da céria são diretamente dependentes do método de síntese e da morfologia das partículas. Nesse contexto, esse trabalho teve como objetivo realizar a síntese através dos métodos dos precursores poliméricos e hidrotérmico assistido por micro-ondas e a caracterização físico-química de nanopartículas do sistema Ce(1-x)MxO2 (M = Cu, Co). Ensaios catalíticos destes pós foram realizados para verificar sua eficácia como catalisadores na reação de oxidação preferencial de monóxido de carbono, e na produção de hidrogênio através da reforma a vapor de etanol. As amostras foram caracterizadas por difração de raios X, espectroscopia UV-Visível, EPR, Raman e fotoluminescência, BET, microscopia eletrônica de varredura e transmissão e TPR. As amostras sintetizadas pelo método dos precursores poliméricos são constituídas por nanopartículas com tamanho da ordem de 30 nm, enquanto que as amostras sintetizadas pelo método hidrotérmico assistido por micro-ondas são constituídas por nanobastões com tamanho da ordem de 10 nm de diâmetro por 70 nm de comprimento. Dentre as amostras sintetizadas pelo método dos precursores poliméricos, o catalisador Ce0,97Cu0,03O2 foi o que apresentou o melhor resultado na conversão do CO (100%)(CO-PROX), e o catalisador Ce0,80Co0,20O2 apresentou 100% de conversão de etanol. Para as amostras sintetizadas pelo método hidrotérmico assistido por micro-ondas o catalisador Ce0,97Cu0,03O2 foi o que apresentou o melhor resultado na conversão do CO (85%)(CO-PROX), e todos os catalisadores com cobalto apresentaram 100% de conversão de etanol. As caracterizações físico-químicas revelaram que diferentes espécies de cobre/cobalto presentes nos catalisadores, o teor de cobre/cobalto presente e as interações entre o cobre/cobalto e o suporte de CeO2 são os fatores que mais contribuem na eficiência dos catalisadores. / Nanostructured materials have been extensively studied, not only by new properties and their possible technological applications, but also by the search for a better understanding of the physical and chemical aspects caused by its small size. Ceria (CeO2) have attracted great interest in recent decades, because it plays a vital role in emerging technologies for applications in sectors ranging from environmental area through the development of new catalysts, passing by the energy area with the development of solid state fuel cells and in new technologies such as spintronics through the development of new materials, the diluted magnetic oxides. The physico-chemical properties of ceria are directly dependent on the synthesis method and the morphology of the particles. In this context, this study aimed the synthesis via polymeric precursors and microwave-assisted hydrothermal methods and the physico-chemical characterization of nanoparticles from the Ce(1-x)MxO2 (M = Cu, Co) system. Catalytic tests of the powders were carried out to verify its efficiency as catalysts on carbon monoxide preferential oxidation reaction, and hydrogen production by steam reforming of ethanol. The samples were characterized by X-ray diffraction, UV-visible, EPR, Raman and photoluminescence spectroscopies, BET, scanning and transmission electron microscopy and TPR. Samples synthesized by polymeric precursors method consist of nanoparticles with sizes of about 30 nm, while the samples synthesized by microwave-assisted hydrothermal method consist of nanorods with 10 nm average diameter and 70 nm length. Among the samples synthesized by the polymeric precursors method, Ce0,97Cu0,03O2 was the one that presented the best result in the CO conversion (100%)(CO-PROX), and the Ce0,80Co0,20O2 catalyst presented 100% of ethanol conversion. For samples synthesized by microwave-assisted hydrothermal method the Ce0,97Cu0,03O2 catalyst was the one that presented the best result in the CO conversion (85%) (CO-PROX), and all catalysts with cobalt presented 100% of ethanol conversion. The physical-chemical characterizations revealed that different species of copper/cobalt present in the catalysts, the copper/cobalt content and interactions between copper/cobalt and the CeO2 support are the main factors that contribute on the efficiency of the catalysts.

Os materiais nanoestruturados vêm sendo extensivamente estudados, não somente pelas novas propriedades e suas possíveis aplicações tecnológicas, mas também pela busca de uma melhor compreensão dos aspectos físicos e químicos causados por suas reduzidas dimensões. A céria (CeO2) tem despertado grande interesse nas últimas décadas, pois tem papel vital em tecnologias emergentes para aplicações em setores que vão desde a área ambiental através do desenvolvimento de novos catalisadores, passando pela área energética com o desenvolvimento de células de combustível em estado sólido e em novas tecnologias como a spintrônica por meio do desenvolvimento de novos materiais, os óxidos magnéticos diluídos. As propriedades físico-químicas da céria são diretamente dependentes do método de síntese e da morfologia das partículas. Nesse contexto, esse trabalho teve como objetivo realizar a síntese através dos métodos dos precursores poliméricos e hidrotérmico assistido por micro-ondas e a caracterização físico-química de nanopartículas do sistema Ce(1-x)MxO2 (M = Cu, Co). Ensaios catalíticos destes pós foram realizados para verificar sua eficácia como catalisadores na reação de oxidação preferencial de monóxido de carbono, e na produção de hidrogênio através da reforma a vapor de etanol. As amostras foram caracterizadas por difração de raios X, espectroscopia UV-Visível, EPR, Raman e fotoluminescência, BET, microscopia eletrônica de varredura e transmissão e TPR. As amostras sintetizadas pelo método dos precursores poliméricos são constituídas por nanopartículas com tamanho da ordem de 30 nm, enquanto que as amostras sintetizadas pelo método hidrotérmico assistido por micro-ondas são constituídas por nanobastões com tamanho da ordem de 10 nm de diâmetro por 70 nm de comprimento. Dentre as amostras sintetizadas pelo método dos precursores poliméricos, o catalisador Ce0,97Cu0,03O2 foi o que apresentou o melhor resultado na conversão do CO (100%)(CO-PROX), e o catalisador Ce0,80Co0,20O2 apresentou 100% de conversão de etanol. Para as amostras sintetizadas pelo método hidrotérmico assistido por micro-ondas o catalisador Ce0,97Cu0,03O2 foi o que apresentou o melhor resultado na conversão do CO (85%)(CO-PROX), e todos os catalisadores com cobalto apresentaram 100% de conversão de etanol. As caracterizações físico-químicas revelaram que diferentes espécies de cobre/cobalto presentes nos catalisadores, o teor de cobre/cobalto presente e as interações entre o cobre/cobalto e o suporte de CeO2 são os fatores que mais contribuem na eficiência dos catalisadores. / Nanostructured materials have been extensively studied, not only by new properties and their possible technological applications, but also by the search for a better understanding of the physical and chemical aspects caused by its small size. Ceria (CeO2) have attracted great interest in recent decades, because it plays a vital role in emerging technologies for applications in sectors ranging from environmental area through the development of new catalysts, passing by the energy area with the development of solid state fuel cells and in new technologies such as spintronics through the development of new materials, the diluted magnetic oxides. The physico-chemical properties of ceria are directly dependent on the synthesis method and the morphology of the particles. In this context, this study aimed the synthesis via polymeric precursors and microwave-assisted hydrothermal methods and the physico-chemical characterization of nanoparticles from the Ce(1-x)MxO2 (M = Cu, Co) system. Catalytic tests of the powders were carried out to verify its efficiency as catalysts on carbon monoxide preferential oxidation reaction, and hydrogen production by steam reforming of ethanol. The samples were characterized by X-ray diffraction, UV-visible, EPR, Raman and photoluminescence spectroscopies, BET, scanning and transmission electron microscopy and TPR. Samples synthesized by polymeric precursors method consist of nanoparticles with sizes of about 30 nm, while the samples synthesized by microwave-assisted hydrothermal method consist of nanorods with 10 nm average diameter and 70 nm length. Among the samples synthesized by the polymeric precursors method, Ce0,97Cu0,03O2 was the one that presented the best result in the CO conversion (100%)(CO-PROX), and the Ce0,80Co0,20O2 catalyst presented 100% of ethanol conversion. For samples synthesized by microwave-assisted hydrothermal method the Ce0,97Cu0,03O2 catalyst was the one that presented the best result in the CO conversion (85%) (CO-PROX), and all catalysts with cobalt presented 100% of ethanol conversion. The physical-chemical characterizations revealed that different species of copper/cobalt present in the catalysts, the copper/cobalt content and interactions between copper/cobalt and the CeO2 support are the main factors that contribute on the efficiency of the catalysts.