Pure and Applied Chemistry

Abstract: Based on our studies on the hybrid catalysts of nanosized (ns) oxide with zeolite, products obtained from the isomerization and hydrocracking of heavier n-paraffins and the role of ns oxide were investigated using a tricomponent catalyst of [Ni-Mo/γ-Al₂O₃], ns oxide, and H-beta zeolite catalyst, which showed high activity, high isomerization selectivity, and mild cracking ability. A concerted effect of the three components was observed. From the observed hybridization state of the catalyst, it was suggested that the concerted effect was obtained because the components become attached to each other. The individual and concerted effects of each component and two components, respectively, were investigated based on the ratio of [Ni-Mo/γ-Al₂O₃]/[H-beta zeolite], the content of ns oxide, the amount of metal, the type of ns oxide species, and the reduction state of metal. It was confirmed that in order to obtain the highest concerted effect, the ratios of [Ni-Mo/γ-Al₂O₃]/[H-beta zeolite] and/or ns oxide/zeolite are important. Furthermore, among the ns oxide species, nsAl₂O₃-nsTiO₂ displayed the highest activity and cracking ability with an over-cracking suppression. In addition to increasing the concerted effect in the tricomponent catalyst, the performance of this catalyst could also be further increased by controlling the amount and reduction state of metal.