Palladium Catalyst in the HBIW Hydrodebenzylation Reaction. Deactivation and Spent Catalyst Regeneration Procedure

Paweł Maksimowski , Tomasz Gołofit , Waldemar Tomaszewski

Abstract

The polycyclic nitramine 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW, CL-20) is synthesized via hydrodebenzylation of 2,4,6,8,10,12-hexabenzyl-2,4,6,8,10,12-hexaazaisowurtzitane (HBIW) over a palladium-based catalyst. This process is the key step in the synthesis of CL-20, a compound with unique energetic and explosive characteristics. The use of CL-20 is restricted at present by the high cost of the hydrodebenzylation process, during which the palladium-based catalyst becomes rapidly deactivated. The catalyst deactivation has now been shown to consist of deposition of the reaction products on the carbon support with simultaneous blocking of the active centers by these products. The HBIW decomposition products can permanently combine with palladium, thereby reducing the number of the active centers on the catalyst. Other byproducts clog the pores of the active carbon and reduce both the surface area of the active carbon and the pore volume. The reaction yield is also reduced by aggregation of palladium particles. A palladium catalyst regeneration procedure which has now been developed, consists of heating the catalyst for a specific time at 350°C in a nitrogen and water vapour stream, and allows partial recovery of the activity of the palladium catalyst in a subsequent HBIW hydrodebenzylation reaction. The specific area and overall pore volume of the regenerated catalyst are also enhanced. The yield from the HBIW hydrodebenzylation reaction using the regenerated catalyst was ca. 42%.
Author Paweł Maksimowski ZMW
Paweł Maksimowski,,
- Department Of High-Energetic Materials
, Tomasz Gołofit ZMW
Tomasz Gołofit,,
- Department Of High-Energetic Materials
, Waldemar Tomaszewski ZMW
Waldemar Tomaszewski,,
- Department Of High-Energetic Materials
Journal seriesCentral European Journal of Energetic Materials, ISSN 1733-7178
Issue year2016
Vol13
No2
Pages333-348
Publication size in sheets0.75
Keywords in EnglishHBIW hydrodebenzylation, palladium-based catalyst, Pd/C deactivation, spent Pd/C catalyst regeneration
URL http://www.wydawnictwa.ipo.waw.pl/CEJEM/contents.html
Languageen angielski
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Maksimowski-1.pdf (file archived - login or check accessibility on faculty) Maksimowski-1.pdf 1.27 MB
Score (nominal)30
ScoreMinisterial score = 25.0, 28-11-2017, ArticleFromJournal
Ministerial score (2013-2016) = 30.0, 28-11-2017, ArticleFromJournal
Publication indicators WoS Impact Factor: 2016 = 1.041 (2) - 2016=1.403 (5)
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