Steam Catalytic Cracking of n-Dodecane over Ni and Ni/Co Bimetallic Catalyst Supported on Hierarchical BEA Zeolite

摘要

Steam catalytic cracking was performed over metal modified BEA zeolite. Nickel and cobalt were introduced to the desilicated BEA zeolite by substitution treatment. The method of metal incorporation used here allowed incorporation of the metal(s) into the framework matrix of BEA in tetrahedral form together with the external surface. The successful incorporation of nickel/cobalt into the BEA framework in tetrahedral form was confirmed from FTIR spectra and UV-vis. The quantity of metals attached to BEA zeolite was calculated by EDX. The changes and defects of the BEA structure were studied from XRD patterns and SEM micrographs. The metal incorporation significantly increased the total acidity, as confirmed by NH3-TPD and pyridine FTIR analysis. The attachment of metals considerably increased the conversion of n-dodecane as compared to the parent sample. The stability of BEA zeolite was also enhanced significantly. However, the addition of Co to Ni incorporated BEA zeolite had a negative effect on both n-dodecane conversion and BEA stability.