Oxidação de hidrocarbonetos em fase liquida catalisada poe zeolitas de poros grandes contendo metais de transição

AUTOR(ES)
DATA DE PUBLICAÇÃO

1997

RESUMO

Were prepared, characterized and tested large pores 12-membered ring channels metallosilicates with BEA (Ø = 7,3 Å) and MTW (Ø= 6,1 Å) structure. BEA structure were obtained with Ti.MTW structure were obtained with V, Cr, Mn and Fe. MTW metallosilicates were tested as catalyst in the cyclohexane oxidation. In this reaction were tested the best solvent among acetone, methanol and acetonitrile and the best oxidants among H2O2 and TBHP. The most active catalyst found were V- and Cr-MTW. For it, the influence of temperature and cyclohexane, H2O2 and catalyst quantity were studied with help of a fractionaI factorial design. For the best conditions, the kinetic study verified that the reaction finished in 24 h for both catalyst. In the recycle study both catalyst had a initial loss of activity and stabilized after the second reaction. Turnover numbers of 1000 for V-MTW and 170 for Cr-MTW were obtained. For Ti-BEA catalyst, the study were done in a univariated way, because synthesis low yield. The solvent, temperature, solvent/cyclohexane/ H2O2 ratio and oxidant influence were studied. The kinetic study showed that the reaction completed in 24 h. The catalyst can be recycled four times without loss of activity. Were obtained turnover number of 30. Because of its large pore diameter, this zeolite can be used for large kinetic diameter substrates. It was tested for the cycIododecane oxidation and good results were obtained, better than these for the cyclohexane oxidation

ASSUNTO(S)

zeolitos peneiras moleculares hidrocarbonetos

ACESSO AO ARTIGO

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