Bifunctional catalyst NiHZSM-5: effects of the nickel incorporation method

The influence of the method used for the metal incorporation, technique and precursor compound on the hydroisomerization of n-decane over the bifunctional NiHZSM-5 catalyst was studied. Two preparation methods, ion exchange and impregnation, using different nickel precursors were tested. Temperature-programmed desorption of ammonia (TPDA), thermogravimetric analyses (TGA), temperature-programmed reduction (TPR), electronic microscopy (SEM, TEM) and atomic absorption spectroscopy (AA) techniques were used to characterize the catalysts. The n-decane hydroisomerization was selected as a test reaction to determine the catalyst activity. These experiments were carried out in a basket type reactor, using a catalyst ground with sodium montmorillonite. The method of nickel incorporation was found to be an important indicator for the activity and selectivity of the catalyst, having a significant influence not only on its hydrogenating properties but also on its acidity. The nickel incorporation technique was mainly affecting the nickel dispersion, while it was affecting both functions, metallic and acid, when the precursor was modified.