Influence of the Si/Al ratio in the hydroisomerization of n-octane over platinum and palladium beta zeolite-based catalysts with or without binder

The isomer selectivity in the palladium catalysts increased with the Si/Al ratio (from 54.3 to 67.8 mol% in samples without binder). The medium-strong acid sites strength of the beta catalysts increased with increasing Si/Al ratios allowing relatively longer residence time of the intermediate carbenium ions on the acid sites. The opposite effect was observed in the platinum catalysts (isomer selectivity shifts from 96.6 towards 78.2 mol% in samples without binder). The presence of hydrogenolysis products in samples with low aluminium content decreased the octane isomer formation. The same effect was observed in the agglomerated catalysts but not as pronounced as in the non-agglomerated ones.