Liquid-phase hydroisomerization of n-octane with three different framework zeolites catalysts with similar Si/Al ratios, USY, mordenite, and beta, was performed in a stirred batch autoclave microcatalytic reactor. As the hydrogenating-dehydrogenating function, platinum supported by impregnation (1 wt %) was used. Additionally, these zeolites were agglomerated with bentonite, the catalytic performance being compared with that obtained for the nonagglomerated samples. To characterize the catalysts, surface area measurements, temperature-programmed desorption of ammonia, atomic absorption spectroscopy, inductively coupled plasma emission spectrophotometry, hydrogen chemisorption, and solid-state 27 Al NMR were used. In all cases, a decrease in the catalytic activity of agglomerated samples, because of the modification of the acidity and the porosity of the zeolites by the binder was observed. The decrease in the acidity after the agglomeration could be attributed to solid-state ion exchange between zeolite protons and clay sodium during the calcination of the catalyst. The binder also modified the porosity of the zeolite providing meso-and macropores, causing a partial blocking of the micropore mouths, which would lead to an increase in the length of the effective diffusional pathway. The presence of aluminium extraframework (EFAL) species in the agglomerated samples could also affect the catalytic performance. Due to the high pressure in the liquid phase, a significantly higher yield of isomers was obtained, and cracking became important only at relatively high average conversions. The maximum n-octane isomers yield obtained with all the nonagglomerated catalysts was very similar (about 75 mol %). This value was reached in 7.5 h for the beta-zeolite-based catalyst and in 10.5 and 23 h for the mordenite-and USY-zeolite ones, respectively.

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In this work, the hydroisomerization of n-octane on mono and bimetallic beta agglomerated zeolite based catalysts was investigated. As the metal function, platinum and combinations with nickel and tin were studied. Test reactions were carried out at 10 bar and 290-410°C. The bimetallic catalyst with the lowest amount of Ni yielded the greatest multibranched selectivity.

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