A New Catalyst Modified with Nanosized Molybdenum Carbides for the Hydroisomerization of n-Alkanes and Its Catalytic Properties in the Hydroisomerization of Diesel Fractions, Part II: Preparation of Bifunctional Hydroisomerization Catalysts

Abstract

The aim of this work is to develop a new hydroisomerization catalyst based on molybdenum carbides that is resistant to the influence of sulfur compounds and applicable for the synthesis of low-pour-point diesel fuels that are similar in parameters to the fuel synthesized using platinum-containing catalysts. In the first part of the work, supports with different porous structures and acidities (Beta, ZSM-5, ZSM-12, and SAPO-31) are synthesized and studied. In the second part of the work, bifunctional catalysts prepared by modifying these supports with nanosized molybdenum carbides are studied. All samples contain the same amount of Mo₂C (10% in terms of the equivalent amount of MoO₃). The catalysts are tested using a model isomerization reaction of n-decane. The catalyst based on silicoaluminophosphate ATO (SAPO-31) proves to be the most effective one. In order to optimize its composition, larger batches of samples with different Mo₂C contents (5, 7 and 10% in terms of the equivalent amount of MoO₃) are prepared. The catalytic properties are studied using the hydroisomerization of actual diesel fractions. The optimum content of Mo₂C (7 wt %) in the bifunctional catalyst is determined.