Post-synthesis design of hierarchical ZSM-5 materials for optimal catalytic performance in the cracking of petroleum feedstock
Abstract
ZSM-5 zeolites are widely used as catalysts in the oil refining and petrochemical industry due to their outstanding catalytic performance.
Despite their undisputed applications, the relative small pore size of ZSM-5 zeolites often imposes intra-crystalline diffusion limitations for reactant molecules, provoking the lower catalyst utilisation. To alleviate such limitations, in this work, an additional network of mesopores has been introduced by the post-synthesis modification. It was found that a hierarchical ZSM-5 material with the large fraction of mesopores (297m2/g) coupled to the preservation of microporous characteristics (strong Brønsted) can be optimally prepared by base treatment in 0.5M NaOH and subsequent acid washing in 0.5M HCl. The gas phase cracking of cumene, carried out at 250oC as a model reaction to test the spacious properties, revealed that the introduction of mesoporosity enhanced the utilisation of active acid sites mostly located inside the micropores of ZSM-5, consequently the superior cumene cracking activity. Thus, the advantages of ZSM-5 zeolites (strong acidity) and mesostructured materials (high accessibility) can be combined to create advanced hierarchical ZSM-5 catalysts for petroleum processing.
References
Michael Stöcker. Gas phase catalysis by zeolites. Microporous and Mesoporous Materials. 2005; 82(3): p. 257 - 292.
Avelino Corma. State of the art and future challenges of zeolites as catalysts. Journal of Catalysis. 2003; 216(1 - 2): p. 298 - 312.
Marcello Rigutto. Cracking and hydrocracking. Zeolites and Catalysis: Synthesis, Reactions and Applications. Wiley-VCH. 2010; 18: p. 547 - 584.
Lei Zhang, Adri N.C.van Laak, Petra E.de Jongh, Krijn P.de Jong. Textural characterization of mesoporous zeolites. Zeolites and Catalysis: Synthesis, Reactions and Applications. Wiley-VCH. 2010; 9: p. 237 - 282.
Javier Pérez-Ramírez, Claus H.Christensen, Kresten Egeblad, Christina H.Christensen, Johan C.Groen. Hierarchical zeolites: Enhanced utilisation of microporous crystals in catalysis by advances in materials design. Chemical Society Reviews. 2008; 37: p. 2530 - 2542.
Maria Milina, Sharon Mitchell, David Cooke, Paolo Crivelli, Javier Pérez-Ramírez. Impact of pore connectivity on the design of long-lived zeolite catalysts. Angewandte Chemie International Edition. 2015; 54(5): p. 1591 - 1594.
Sander van Donk, Andries H.Janssen, Johannes H.Bitter, Krijn P.de Jong. Generation, characterization and impact of mesopores in zeolite catalysts. Catalysis Reviews: Science and Engineering. 2003; 45(2): p. 297 - 319.
Johan C.Groen, Jacob A.Moulijn, Javier Pérez- Ramírez. Desilication: on the controlled generation of mesoporosity in MFI zeolites. Journal of Materials Chemistry. 2006; 16: p. 2121 - 2131.
Jiří Čejka, Svetlana Mintova. Perspectives of micro/ mesoporous composites in catalysis. Catalysis Reviews: Science and Engineering. 2007; 49(4): p. 457 - 509.
Yu Liu, Thomas J.Pinnavaia. Aluminosilicate mesostructures with improved acidity and hydrothermal stability. Journal of Materials Chemistry. 2002; 12: p. 3179 - 3190.
Vu Xuan Hoan, Matthias Schneider, Ursula Bentrup, Dang Thanh Tung, Phan Minh Quoc Binh, Nguyen Anh Duc, Udo Armbruster, Andreas Martin. Hierarchical ZSM-5 materials for an enhanced formation of gasoline- range hydrocarbons and light olefins in catalytic cracking of triglyceride-rich biomass. Industrial & Engineering Chemistry Research. 2015; 54(6): p. 1773 - 1782.
Vu Xuan Hoan, Norbert Steinfeldt, Udo Armbruster, Andreas Martin. Improved hydrothermal stability and acidic properties of ordered mesoporous SBA- 15 analogs assembled from nanosized ZSM-5 precursors. Microporous and Mesoporous Materials. 2012; 164: p. 120 - 126.
Hiroshi Mochizuki, Toshiyuki Yokoi, Hiroyuki Imai, Seitaro Namba, Junko N.Kondo, Takashi Tatsumi. Effect of desilication of H-ZSM-5 by alkali treatment on catalytic performance in hexane cracking. Applied Catalysis A: General. 2012; 449: p. 188 - 197.
A.Corma, BW.Wojciechowski. The catalytic cracking of cumene. Catalysis Reviews: Science and Engineering. 1982; 24(1): p. 1 - 65.
Masaru Ogura, Shin-ya Shinomiya, Junko Tateno, Yasuto Nara, Mikihiro Nomura, Eiichi Kikuchi, Masahiko Matsukata. Alkali-treatment technique-new method for modification of structural and acid-catalytic properties of ZSM-5 zeolites. Applied Catalysis A: General. 2001; 219(1 - 2): p. 33 - 43.
Kreste Egeblad, Christina H.Christensen, Marina Kustova, Claus H.Christensen. Templating mesoporous zeolites. Chemistry of Materials. 2008; 20(3): p. 946 - 960.
Liang Zhao, Baojian Shen, Jinsen Gao, Chunming Xu. Investigation on the mechanism of diff usion in mesopore structured ZSM-5 and improved heavy oil conversion. Journal of Catalysis. 2008; 258(1): p. 228 - 234.
S.Al-Khattaf, H.de Lasa. The role of diffusion in alkyl-benzenes catalytic cracking. Applied Catalysis A: General. 2002; 226 (1 - 2): p. 139 - 153.
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