Synthesis, characterization and catalytic testing of MCM-22 derived catalysts for n-hexane cracking

• Published in: Scientific reports Vol. 10; no. 1; p. 21786
• Main Authors: Ahmad, Ali, Naqvi, Salman Raza, Rafique, Muhammad, Nasir, Habib, Sarosh, Ali
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.12.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301; 639/638; 639/925; Catalysts; Catalytic cracking; High temperature; Humanities and Social Sciences; multidisciplinary; n-Hexane; Oxalic acid; Science; Science (multidisciplinary); Zeolites
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-78746-9

Layered zeolites and their delaminated structures are novel materials that enhance the catalytic performance of catalysts by addressing diffusion limitations of the reactant molecules. n-Hexane catalytic cracking was observed over MCM-22 layered zeolite and its derivative structures over the temperature range of 450–650 °C for the production of olefins. MCM-22, H-MCM-22, and ITQ-2 zeolites were prepared by the hydrothermal method. Oxalic acid was used as a dealuminating reagent to obtain H-MCM-22 with various Si/Al ratios ranging from 09–65. The prepared samples were characterized by XRD, SEM, TGA, and BET. The cracking of n-hexane was carried out by Pyro/GC–MS. It was observed that the selectivity for olefins was improved by increasing the Si/Al ratio. H-MCM-22–10% produced the highest relative olefinic concentration of 68% as compared to other dealuminated structures. Moreover, the product distribution showed that higher reaction temperature is favorable to produce more olefins. Furthermore, a comparison between ITQ-2 and MCM-22 derived structures showed that ITQ-2 is more favorable for olefins production at high temperatures. The concentration of relative olefins was increased up to 80% over ITQ-2 at 650 °C.