MOR/SBA-15 Composite Catalysts with Interconnected Meso/Micropores for Improved Activity and Stability in Isopropylation of Naphthalene

• Published in: ChemCatChem 2015-08, Vol.7 (15), p.2354-2360
• Main Authors: Banu, Marimuthu, Lee, Young Hye, Magesh, Ganesan, Nam, Chang-Mo, Lee, Jae Sung
• Format: Article
• Language: English
• Subjects: alkylation; carbon; hydrothermal synthesis; mesoporous materials; microporous materials
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.201500335

The isopropylation of naphthalene with isopropyl alcohol was studied over composites of MOR/SBA‐15 in a high‐pressure, fixed‐bed reactor. The MOR catalyst showed a high 2,6‐/2,7‐diisopropyl naphthalene (DIPN) ratio of 1.75, but a low naphthalene conversion (54 %) and fast deactivation of the catalyst. The composites of MOR/SBA‐15 were prepared by a hydrothermal recrystallization process to obtain hierarchical micro/mesopores. During the process, MOR recrystallized in the mesopores of SBA‐15, the structure of which was stabilized by carbon coating formed on the pore walls as a template. The best prepared MOR/SBA‐15 catalyst achieved a high conversion of 85 %, high stability, and less coking, while maintaining the high 2,6‐/2,7‐DIPN ratio (≈1.8). The modified micro/mesopore structure allowed facile diffusion of bulky molecules to and from active catalytic sites located in the small MOR pores as a result of the connection between the two types of pores in the MOR/SBA‐15 composite. Networking of big and small: To improve naphthalene conversion in isopropylation of naphthalene, a hierarchical meso/micropore structure of zeolite composites is achieved by combining micropores of MOR with mesopores of SBA‐15. In the hydrothermal recrystallization process, MOR recrystallizes in the mesopores of SBA‐15 stabilized by carbon coating formed on the pore walls as a template.