Insights into Catalytic Cracking of n-Heptane over Ga-Doped Hierarchical ZSM-5

Light olefins (C-2-C-4=) play crucial roles in the development of the modern chemical industry. Catalytic cracking of naphtha represents an alternative route to traditional steam cracking to obtain light olefins. In this work, n-heptane is selected as a model compound, and Ga is incorporated during the synthesis of ZSM-5 zeolites to modify their properties. The study investigated the influence of Ga on the conversion rate and product distribution in the catalytic cracking of n-heptane over these zeolites. Additionally, different synthesis methods were used to control the formation of mesopores within zeolites, examining the impact of various mesopore structures on the performance of zeolites. Several characterization techniques were utilized to quantify the potential active sites. This approach improved the selectivity of lower olefins and propylene/ethylene ratios under conditions of higher space velocity and, by controlling the presence of different types of mesopores, mitigated the rapid deactivation often seen in Ga-modified zeolites.