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@PhDThesis{Okamoto:2015:DeMaCa,
               author = "Okamoto, Sayuri",
                title = "Desenvolvimento de materiais catal{\'{\i}}ticos para 
                         decomposi{\c{c}}{\~a}o do N2O para aplica{\c{c}}{\~o}es 
                         aeroespaciais",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2015",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2015-11-25",
             keywords = "{\'o}xidos mistos, catalisadores m{\'a}ssicos, 
                         decomposi{\c{c}}{\~a}o de N2O, propulsor, mixed oxides, bulk 
                         catalysts, N2O decomposition, thruster.",
             abstract = "Este trabalho teve como objetivo o desenvolvimento de um 
                         catalisador m{\'a}ssico {\`a} base de {\'o}xidos de cobalto, 
                         mangan{\^e}s e alum{\'{\i}}nio, com estrutura do tipo 
                         espin{\'e}lio, capaz de decompor espontaneamente o {\'o}xido 
                         nitroso (N\$_{2}\$O) para emprego em um propulsor de 2 N, 
                         buscando sempre temperaturas de igni{\c{c}}{\~a}o da 
                         rea{\c{c}}{\~a}o inferiores a 773 K. Inicialmente foram 
                         estudadas as altera{\c{c}}{\~o}es nas propriedades 
                         f{\'{\i}}sico-qu{\'{\i}}micas e texturais dos pellets obtidos, 
                         a partir de diversas t{\'e}cnicas de s{\'{\i}}nteses destes 
                         materiais, tais como: tratamento hidrot{\'e}rmico, 
                         coprecipita{\c{c}}{\~a}o, sol-gel e sol-combust{\~a}o. O 
                         m{\'e}todo de s{\'{\i}}ntese por coprecipita{\c{c}}{\~a}o, 
                         com emprego de dois agentes precipitantes (KOH e 
                         K\$_{2}\$CO\$_{3}\$), foi o {\'u}nico que gerou um material 
                         mold{\'a}vel. Foi tamb{\'e}m estudada a influ{\^e}ncia da 
                         varia{\c{c}}{\~a}o da raz{\~a}o molar dos c{\'a}tions 
                         met{\'a}licos (Co:Mn:Al) na decomposi{\c{c}}{\~a}o do 
                         N\$_{2}\$O. Testes de bancada mostraram que a raz{\~a}o molar 
                         4:1:1 foi aquela que apresentou a maior atividade 
                         catal{\'{\i}}tica, devida a presen{\c{c}}a do par redox 
                         Co\$^{2+}\$/Co\$^{3+}\$. Os materiais foram caracterizados por 
                         Difratometria de Raios X, Adsor{\c{c}}{\~a}o de Nitrog{\^e}nio, 
                         Dessor{\c{c}}{\~a}o de N\$_{2}\$O a Temperatura Programada, 
                         Espectrometria Fotoeletr{\^o}nica de Raios X e Termogravimetria. 
                         Posteriormente, foram otimizadas as dimens{\~o}es 
                         geom{\'e}tricas do leito catal{\'{\i}}tico do micropropulsor de 
                         2 N, empregando a metodologia de Planejamento de Experimentos. 
                         Para tanto, foi feito um propulsor em m{\'o}dulos, com diferentes 
                         geometrias do leito catal{\'{\i}}tico, carregado com o material 
                         contendo a raz{\~a}o molar 4:1:1. Finalmente, foi fabricado um 
                         micropropulsor com empuxo te{\'o}rico de 2 N, onde foram 
                         efetuadas campanhas de testes compostas de tiros 
                         cont{\'{\i}}nuos e pulsados, sendo monitorado o empuxo, a 
                         press{\~a}o e a temperatura do sistema. Os resultados obtidos com 
                         o catalisador 4Co1Mn1Al (4:1:1) neste propulsor, foram comparados 
                         com os do catalisador (5\% 
                         Rh\$_{2}\$O\$_{3}\$/Al\$_{2}\$O\$_{3}\$) tradicionalmente 
                         empregado na decomposi{\c{c}}{\~a}o do N\$_{2}\$O. O 
                         catalisador 4Co1Mn1Al apresentou maior atividade nesta 
                         rea{\c{c}}{\~a}o, exibindo uma efici{\^e}ncia da velocidade 
                         caracter{\'{\i}}stica em torno de 97,5\%, valor este bem 
                         superior {\`a}quele obtido pelo catalisador tradicional de 
                         62,5\%. ABSTRACT: The objective of this work was the development 
                         of bulk catalyst based on cobalt, manganese and aluminium oxide 
                         with spinel structure for nitrous oxide decomposition reaction 
                         applied to microthruster of 2 N with ignition temperature less 
                         than 773 K. Initially were studied modification on 
                         physical-chemical and textural properties on obtained pellets 
                         using a variety of synthesis methods as hydrothermal, 
                         coprecipitation, sol-gel and sol-combustion. Only the 
                         coprecipitation method using two different precipitation agents 
                         (KOH and K\$_{2}\$CO\$_{3}\$) allowed conformable materials. 
                         Later, the influence of different molar ratio of metallic cations 
                         (Co:Mn:Al) was investigated. In laboratory scale tests the molar 
                         ratio of 4:1:1 presented better catalytic activity and presented 
                         redox par Co\$^{2+}\$/Co\$^{3+}\$ on its surface composition. 
                         All the materials were characterized using X-ray diffraction, 
                         nitrogen adsorption, nitrous oxide desorption in programmed 
                         temperature, X-ray photoeletronic emission spectrometry and 
                         thermogravimmetry technics. The catalytic chamber dimensions were 
                         optimized using Design of Experiments methods. For this purpose, 
                         modular thrusters with different geometries containing molar ratio 
                         4:1:1 were used. Finally, a microthruster with theoretical thrust 
                         of 2 N was manufactured where all the tests campaign where 
                         performed. This campaign was composed of continuous and pulsed 
                         fires monitoring pressure, thrust and temperatures of the system. 
                         The tests results obtained for 4Co1Mn1Al (4:1:1) using this 
                         microthruster were compared with one employing 5\% 
                         Rh\$_{2}\$O\$_{3}\$/Al\$_{2}\$O\$_{3}\$, a traditional 
                         catalyst used for nitrous oxide decomposition. The exhaust 
                         characteristic velocity efficiency for 4Co1Mn1Al was 97.5\% which 
                         is superior of the value obtained for 5\% 
                         Rh\$_{2}\$O\$_{3}\$/Al\$_{2}\$O\$_{3}\$ of 62.5\%.",
            committee = "Vieira, Ricardo (presidente/orientador) and Soares Neto, 
                         Tur{\'{\i}}bio Gomes and Mineiro, S{\'e}rgio Luiz and Bastos, 
                         Luiz Claudio Antunes and Cortez, Gilberto Garcia",
           copyholder = "SID/SCD",
         englishtitle = "The development of catalytic materials for N2O decomposition 
                         reaction for aerospace purpose",
             language = "pt",
                pages = "125",
                  ibi = "8JMKD3MGP3W34P/3KFLBBP",
                  url = "http://urlib.net/rep/8JMKD3MGP3W34P/3KFLBBP",
           targetfile = "publicacao.pdf",
        urlaccessdate = "03 dez. 2020"
}


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