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Orientador(es)
Resumo(s)
In this paper the relation between activity and acidity in a variety of ZSM-5 zeolite catalysts, with different Si/Al ratios and different protonic content, is analysed and a quantitative correlation is obtained. The acid site strength distribution was estimated using temperature-programmed desorption (TPD) of ammonia by applying a digital deconvolution method to the curves. These data were then correlated with experimental catalytic activity data for the same catalysts towards n-heptane cracking reaction, by means of a Brönsted-type equation similar to the ones used for homogeneous acid catalysis and already used for other zeolites. It can be noticed that the same types of equation that are used for homogeneous acid catalysis also hold for heterogeneous acid catalysis and that the activation energy for ammonia desorption can be used as acid-strength scale for the purpose of correlation with catalytic activity.
Descrição
Palavras-chave
Zeolites ZSM-5 zeolite Acidity Activity Paraffin transformation
Contexto Educativo
Citação
COSTA, Carla; [et al] – Activity–acidity relationship in zeolite ZSM-5. Application of Brönsted-type equations. Journal of Molecular Catalysis A: Chemical. ISSN 1381-1169. Vol. 154, N.º 1-2 (2000), pp. 193-201
Editora
Elsevier