Catalytic decomposition of polystyrene. The role of acid and basic centers

Marek Marczewski , Elżbieta Kamińska , Hanna Marczewska , M. Godek , Gabriel Rokicki , Janusz Sokołowski

Abstract

The influence of the acid and basic properties of a catalyst on the selectivity of polystyrene transformation was studied. The properties of silicaalumina SiO2–Al2O3(45%) dotted with NaOH from 1 to 20 wt% and γ-Al2O3 containing 1 to 8 wt% NaOH or H2SO4 were examined using the test reactions of cumene (acid) and diacetone alcohol (base) transformation. These catalysts were used in polystyrene transformations. It was found that polystyrene decomposition involves thermal and catalytic transformation. In the first case, two main reaction pathways are involved: gradual depolymerization to the monomer (styrene) and pyrolysis leading to the formation of different volatile oligomers (dimers, trimers, tetramers.). The latter species react solely over the catalyst active centers. Linear dimers of styrene activated by Brønsted acid sites undergo decomposition to styrene and ethylbenzene as well as to toluene and α-methylstyrene. Consecutive transformation of the products leads to a simultaneous hydrogen (H+ and H−) production and coke formation. The latter ions are active in hydrogen transfer reactions which causes hydrogenation of styrene to ethylbenzene. In the presence of base catalysts selective styrene formation takes place and transformation leading to coke are slower hence ethylbenzene formation is suppressed. In the presence of acid catalysts linear dimers can also isomerize to cyclic derivatives which after dealkylation give benzene and methylindane. The later product in isomerization and hydrogen transfer reactions forms methylindene and naphthalene. The higher styrene oligomers reactions are catalyzed by both acid and basic sites leading mainly the monomer, i.e. styrene formation.
Author Marek Marczewski (FC / DCOC)
Marek Marczewski,,
- Department Of Catalysis And Organometallic Chemistry
, Elżbieta Kamińska (FC / DCOC)
Elżbieta Kamińska,,
- Department Of Catalysis And Organometallic Chemistry
, Hanna Marczewska (FC / DCOC)
Hanna Marczewska,,
- Department Of Catalysis And Organometallic Chemistry
, M. Godek (FC / CPCT)
M. Godek,,
- Chair Of Polymer Chemistry And Technology
, Gabriel Rokicki (FC / CPCT)
Gabriel Rokicki,,
- Chair Of Polymer Chemistry And Technology
, Janusz Sokołowski (FC / CChT)
Janusz Sokołowski,,
- Chair of Chemical Technology
Journal seriesApplied Catalysis B: Environmental, ISSN 0926-3373
Issue year2013
Vol129
Pages236-246
Publication size in sheets0.5
Keywords in EnglishPolystyrene recycling; Polystyrene decomposition; Solid acids; Solid bases; Test reactions; Alumina; Alkalized alumina; Sulfated alumina; Silicaalumina; Alkalized silicaalumina
ASJC Classification1508 Process Chemistry and Technology; 2300 General Environmental Science; 1503 Catalysis
DOIDOI:10.1016/j.apcatb.2012.09.027
URL http://www.sciencedirect.com/science/article/pii/S0926337312004286
Languageen angielski
File
111.pdf 581.2 KB
Score (nominal)45
Score sourcejournalList
ScoreMinisterial score = 45.0, 02-02-2020, ArticleFromJournal
Ministerial score (2013-2016) = 45.0, 02-02-2020, ArticleFromJournal
Publication indicators WoS Citations = 30; Scopus Citations = 36; Scopus SNIP (Source Normalised Impact per Paper): 2013 = 2.164; WoS Impact Factor: 2013 = 6.007 (2) - 2013=6.423 (5)
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