Deactivation and Regeneration of Palladium Catalysts for Hydrogenation Debenzylation of 2,4,6,8,10,12-Hexabenzyl-2,4,6,8,10,12-Hexaazaisowurtzitane (HBIW)
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Published:2022-12-01
Issue:12
Volume:12
Page:1547
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ISSN:2073-4344
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Container-title:Catalysts
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language:en
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Short-container-title:Catalysts
Author:
Zhang Qunfeng,Wang Mei,Qian Jiacheng,Lou Shuyuan,Jin Jianhong,Li Bingcheng,Lu Chunshan,Feng Feng,Lv Jinghui,Wang Qingtao,Li Xiaonian
Abstract
2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW, also known as CL-20) is an important energetic compound. As one of the representatives of the third generation of energetic materials, it has an excellent performance, providing broad application prospects for the development of new weapons and equipment. The synthesis of CL-20 is usually obtained from 2,4,6,8,10,12-hexabenzyl-2,4,6,8,10,12-hexaazaisowurtzitane (HBIW) through two catalytic hydrogenolysis and debenzylation reactions, followed by nitration. The most critical step is the hydrogenolysis debenzyl-acetylation process of HBIW because this process requires a large amount of expensive palladium-based catalyst, and the catalyst is completely deactivated after one use. In response to this problem, there is no suitable solution at present, resulting in the high cost of the entire synthesis process. Therefore, reducing the production cost of CL-20 by increasing the catalyst stability is one of the current research priorities. By using AAS, XRD, XPS, TEM, BET, TG and other characterization techniques, the reasons for catalyst deactivation were explored. Studies have shown that the main reason for catalyst deactivation is that a large number of blockages accumulate in the pores of the catalyst after the reaction, which greatly weakens the transfer of the reactant HBIW, intermediate substances, and product 2,6,8,12-tetraacetyl-4,10-dibenzyl-2,4,6,8,10,12-hexaazaisowurtzitane (TADBIW) in the catalyst pores, and the blockage may block the active site of the catalyst. A regeneration treatment method for catalyst deactivation was developed. This method uses chloroform and glacial acetic acid as reagents, which, when combined with stirring and ultrasonic operation, finally restores the activity of the Pd(OH)2/C catalyst. The BET and TG parameters of the regenerated catalyst indicate that catalyst textural and structural properties have greatly recovered, indicating that this treatment method can remove the blockages in the catalyst pores.
Funder
National Natural Science Foundation of China
Subject
Physical and Theoretical Chemistry,Catalysis,General Environmental Science
Reference41 articles.
1. Cannizzo, L.F., Edwards, W.W., and Wardle, R.B. (1998). Synthesis of 2,4,6,8,10,12-hexabenzyl-2,4,6,8,10,12-hexaazatetracyclo 5.5.0.05,9.03,11!dodecane. (5723604A), U.S. Patent. 2. Tang, X., Zhu, R., Shi, T., Wang, Y., Niu, X., Zhang, Y., Zhu, J., Li, W., Hu, W., and Xu, R. (2022). Research progress and key issues of hydrodebenzylation of hexabenzylhexaazaisowurtzitane (HBIW) in the synthesis of high energy density material hexanitrohexaazaisowurtzitane (HNIW). Materials, 15. 3. An overview on importance, synthetic strategies and studies of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW);Viswanath;Def. Technol.,2016 4. Norris, W.P., and Nielsen, A.T. (2011). Catalitic Synthesis of Caged Polynitraminepolynitramine. (8017768A), U.S. Patent. 5. Lian, L.U., Yu, O.U., and Li, C.I. (2003). Synthesis of HNIW from TADBIW. J. Shijiazhuang Teach. Coll. June.
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