The Synthesis of Core-Shell Encapsulated Metal Catalysts for Conversion of Methanol to Aromatics
DOI:
https://doi.org/10.22399/ijcesen.3072Keywords:
HZSM-5, Silicalite-1, Core-shell, MTA, AromaticsAbstract
A core-shell encapsulated metal catalyst was prepared, and its catalytic performance in the methanol-to-aromatics (MTA) reaction was investigated. This study introduces a simple secondary hydrothermal synthesis method based on the traditional preparation of HZSM-5 catalyst resulting in a nanoparticle with HZSM-5 catalyst encapsulating 2Gd%/S-1 with hollow and hierarchical pores (2Gd%/S-1@HZSM-5). This catalyst offers several advantages. First, the inner silicalite-1 layer shields the aluminum species within the HZSM-5 framework, thus passivating some of the strong acid sites on the catalyst surface. This in turn inhibits continuous reactions that result from the overly acidic surfaces. The 2Gd%/S-1@HZSM-5 catalyst demonstrates high selectivity for aromatics (59.4%), particularly BTX (benzene, toluene, and xylene), in the methanol-to-aromatics reaction (MTA). This selectivity arises from the catalyst's suitable acidity and optimized porous system. Importantly, the selectivity for C9+ aromatics is low, thus indicating effective inhibition of continuous reactions of BTX products on the catalyst surface due to low pH. Furthermore, the hydrothermal stability of the 2Gd%/S-1@HZSM-5 catalyst is significantly higher. Therefore, this method holds promise for the widespread development
of novel catalysts with hollow layered porous systems, tunable pH, and high hydrothermal stability.
References
[1] Ji, Y. J., Zhang, B., Xu, L., Wu, H. H., Peng, H. G., Chen, L. Y., Liu, M., Wu, P., (2011). Core/shell-structured Al-MWW@B-MWW zeolites for shape-selective toluene disproportionation to para-xylene. J. Catal. 283; 168-177.
[2] Zhao, Y., Wu, H., Tan, W., Zhang, M., Guo, X., (2010). Effect of metal modification of HZSM-5 on catalyst stability in the shape-selective methylation of toluene. Catal. Today, 156; 69-73.
[3] Li, J., Xiang, H., Liu, M., Wang, Q., Zhu, Z., Hu, Z., (2014). The deactivation mechanism of two typical shape-selective HZSM-5 catalysts for alkylation of toluene with methanol. Catal. Sci. Technol. ;4 2639-2649.
[4] Song, Y., Sun, C., Shen, W., Lin, L., (2007). Hydrothermal post-synthesis of HZSM-5 zeolite to enhance the coke-resistance of Mo/HZSM-5 catalyst for methane dehydroaromatization reaction: reconstruction of pore structure and modification of acidity. Appl. Catal. A, 317; 266-274.
[5] Sun, X., Mueller, S., Liu, Y., Shi, H., Haller, G. L., Sanchez-Sanchez, M., (2014). On reaction pathways in the conversion of methanol to hydrocarbons on HZSM-5. J. Catal. 317; 185-197.
[6] Lopez-Sanchez, J. A., Conte, M., Landon, P., Zhou, W., Bartley, J. K., Taylor, S. H., (2012). Reactivity of Ga2O3 clusters on zeolite ZSM-5 for the conversion of methanol to aromatics. Catal. Lett. 142; 1049-1056.
[7] Chen, Z. Y, Ni, Y. M., Zhi, Y. C., Wen, F. L., Zhou, Z. Q., Wei, Y. G., Zhu, W. L., Liu, Z. M., (2018). Coupling of methanol and carbon monoxide over HZSM-5 to form aromatics. Angew. Chem. Int. Edit. 57; 12549-12553.
[8] Niu, X., Gao, J., Miao, Q., Dong, M., Wang, G., Fan, W., (2014). Influence of preparation method on the performance of Zn-containing HZSM-5 catalysts in methanol-to-aromatics. Micropor. Mesopor. Mat. 197; 252-261.
[9] Liang, T., Chen, J., Qin, Z., Li, J., Wang, P., Wang, S., (2016). Conversion of methanol to olefins over HZSM-5 zeolite: reaction pathway is related to the framework aluminum siting. ACS Catal. 6; 7311-7325.
[10] Zhang, J., Qian, W., Kong, C., Wei, F., (2015). Increasing para-xylene selectivity in making aromatics from methanol with a surface-modified Zn/P/ZSM-5 catalyst. ACS Catal, 5; 2982-2988.
[11] Lee, S., Choi, M., )2019). Unveiling coke formation mechanism in MFI zeolites during methanol-to-hydrocarbons conversion. J. Catal. 375; 183-192.
[12] Wang, N., Hou, Y., Sun, W., Cai, D., Chen, Z., Liu, L., (2019). M. (2013). Catalyst deactivation by coke formation in microporous and desilicated zeolite HZSM-5 during the conversion of methanol to hydrocarbons. J. Catal. 307; 62-73.
[14] Wang, K., Dong, M., Niu, X., Li, J., Qin, Z., Fan, W., (2018). Highly active and stable Zn/ZSM-5 zeolite catalyst for the conversion of methanol to aromatics: effect of support morphology. Catal. Sci. Technol. 8; 5646-5656.
[15] Wan, W., Fu, T., Qi, R., Shao, J., Li, Z., (2016). Co-effect of Na+ and TPA+ in alkali treatment on fabrication of mesoporous ZSM-5 catalyst for methanol to hydrocarbons reaction. Ind. Eng. Chem. Res. 55; 13040-13049.
[16] Conte, M., Lopez-Sanchez, J. A., He, Q., Morgan, D. J., (2011). Hutchings, G. J., Modified zeolite ZSM-5 for the methanol to aromatics reaction. Catal. Sci. Technol. 2; 105-112.
[17] Ni, Y., Zhu, W., Liu, Z., (2021). Formaldehyde intermediate participating in the conversion of methanol to aromatics over zinc modified HZSM-5. J. Energy Chem. 54; 174-178.
[18] Dong, P., Zhang, Y., Li, Z., Yong, H., Li, G., Ji, D., (2019). Enhancement of the utilization of methanol in the alkylation of benzene with methanol over 3-aminopropyltriethoxysilane modified HZSM-5. Catal. Commun. 123; 6-10.
[19] Tian, H., Lv, J., Liang, X., Tang, X., Zha, F., (2018). Tuning morphology of Zn/HZSM-5 on catalytic performance in methanol aromatization. Energy Technol-Ger., 6; 1986-1993.
[20] Li, G. X., Wu, C., Dong, P., Ji, D., Zhang, Y. F, (2020). Core-shell HZSM-5@silicalite-1 composite: controllable synthesis and catalytic performance in alkylation of toluene with methanol. Catal. Lett. 150; 1923-1931.
[21] Wang, X. Y., Wen, M., Wang, C. Z., Ding, J., Sun, Y., Liu, Y., (2014). Microstructured fiber@HZSM-5 core-shell catalysts with dramatic selectivity and stability improvement for the methanol-to-propylene process. Chem. Commun. 50; 6343-6345.
[22] Jin, Z., Liu, S., Qin, L., Liu, Z., Wang, Y., Xie, Z., (2013). Methane dehydroaromatization by Mo-supported MFI-type zeolite with core-shell structure. Appl. Catal. A-Gen. 453; 295-301.
[23] Kong, D., Liu, Z., Fang, D., (2009). Epitaxial growth of core-shell ZSM-5/silicalite-1 with shape selectivity. Chinese J. Catal. 30; 885-890.
[24] Khaledi, K., Haghighi, M., Sadeghpour, P., (2017(. On the catalytic properties and performance of core-shell ZSM-5@MnO nanocatalyst used in conversion of methanol to light olefins. Micropor. Mesopor. Mat., 246, 51-61.
[25] Wu, Y., Li, J., Chai, Y., Guo, H., Liu, C., (2015). Synergetic effect of HZSM-5/silicalite-1@Pt/Al2O3 core-shell catalyst to enhance the selective hydrogenation of p-xylene. J. Membrane Sci. 496; 70-77
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