On the H-ZSM-5 catalyzed formation of ethylene from methanol or higher olefins

Dessau, R. M.

doi:10.1016/0021-9517(86)90204-6

Cited by 188 publications

(141 citation statements)

References 16 publications

Supporting

Mentioning

133

Contrasting

Unclassified

Order By: Relevance

“…Recently, however, experimental studies by Haw and co-workers [3,4] as well as our own theoretical results [5] provided strong evidence for the complete failure of the direct routes. The most likely alternative, which is more in accordance with experimental observations, [6] is given by the "hydrocarbon-pool" (HP) proposal, [7,8] in which organic species trapped in the zeolite pores undergo repeated methylation followed by olefin elimination. To date, the elementary steps governing this process are not well understood.…”

mentioning

confidence: 54%

Zeolite Shape‐Selectivity in the gem‐Methylation of Aromatic Hydrocarbons

et al. 2007

View full text Add to dashboard Cite

mentioning

confidence: 54%

Zeolite Shape‐Selectivity in the gem‐Methylation of Aromatic Hydrocarbons

et al. 2007

View full text Add to dashboard Cite

“…The actual active catalyst is thus the combined organic-inorganic supramolecular complex of the HP and zeolite framework. Thus far, aromatics, typically polymethylbenzenes (PMB), as well as alkenes, [14][15][16] were found to be the main HP species. The corresponding reaction mechanisms involving these HP compounds are known as the aromatic and alkene routes, respectively.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Simulations Elucidate the Role of Naphthalenic Species during Methanol Conversion within H‐SAPO‐34

Hemelsoet

Nollet

Speybroeck

et al. 2011

Chemistry A European J

View full text Add to dashboard Cite

The role of naphthalenic species during the methanol-to-olefins (MTO) process in a silicoaluminophosphate zeolitic material exhibiting the chabazite topology (H-SAPO-34) has been studied from first principles. These species could either act as active olefin-eliminating compounds or as precursors for deactivating species. Results incorporating van der Waals contributions for finite large clusters point out that successive methylation steps of naphthalenic compounds are feasible. The calculated intrinsic activation barrier is relatively independent of the number of methyl groups already attached on the aromatic compound and is approximately 140 kJ mol(-1). The influence of the composition of the catalyst and hence the acidic strength on the intrinsic chemical kinetics was investigated in detail through comparison with the isostructural high-silicon material. Apparent chemical kinetics, starting from adsorbed methanol on the acid site, were also computed. The initiation steps of the side-chain route starting from a trimethylated naphthalenium ion were also examined. The actual side-chain methylation exhibits a high barrier and hence this mechanism involving methylated naphthalenes is not expected to be an active ethene-eliminating route in H-SAPO-34.

show abstract

“…A number of zeolites have been used as catalysts for the reaction, such as ZSM-5 [2], modi®ed USY [3] and SAPO-34 [4] zeolites, etc. SAPO-34 has been found to be the most eective catalyst for the reaction, but the deactivation due to the build-up of surface carbonaceous residues is still a problem.…”

Section: Introductionmentioning

confidence: 99%