标题：DECOMPOSIÇÃO DO METANO EM CATALISADORES DE COBALTO SUPORTADOS – O EFEITO DAS PROPRIEDADES TEXTURAIS NA ATIVIDADE CATALÍTICA PARA FORMAÇÃO DE CARBONO FILAMENTAR
摘要：Now a day, numerous investigations have been made to study nanostructures materials formations. These structures can be formed by chemical reactions on metallic surfaces, especially nickel and cobalt. In this work, cobalt catalysts supported on SiO2, Al2O3 and Nb2O5 were prepared to be tested for methane decomposition with H2 and carbon filaments productions. It seems that metallic particles sizes, there dispersions on support, the surface area and supports structures strongly influence this process. BET, X ray diffraction (XRD), hydrogen chemisorption and temperature programmed reduction (TPR) techniques were used to characterize catalysts surface. Average metal particles sizes of cobalt catalysts could be calculated by chemisorption measures. The catalytic measurements were performed in order to determine the catalytic activity for the decomposition of methane, with carbon deposits formations. The results indicate that cobalt catalysts supported on silica reduced at 500oC exhibit the most conversions.
