| Titre : | Catalytic conversion of ethylene to propylene and butenes over H−ZSM-5 (2010) |
| Auteurs : | Baomin Lin, Auteur ; Qinghong Zhang, Auteur ; Ye Wang, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Industrial & engineering chemistry research (Vol. 48 N° 24, Décembre 2009) |
| Article en page(s) : | pp. 10788–10795 |
| Note générale : | Industrial chemistry |
| Langues : | Anglais |
| Tags : | Catalytic--Conversion--Ethylene--Propylene--Butenes--H− ; ZSM-5 |
| Résumé : | Among 11 kinds of molecular sieves examined, H−ZSM-5 exhibited the highest activity for the direct conversion of ethylene to propylene. The conversion of ethylene was 58% and the selectivities to propylene and butenes were 42% and 21%, respectively, over H−ZSM-5 at 723 K. Our studies demonstrate that the conversion of ethylene increases with the degree of H+ exchange in the H−Na−ZSM-5 series of samples with different H+ exchange degrees and the Al content in the H−ZSM-5 samples with different Si/Al ratios. The strong Brønsted acid sites are proposed to account for the conversion of ethylene. The modification of H−ZSM-5 with phosphorus or boron could enhance the selectivity of propylene but decreased the conversion of ethylene due to the decreased acidity. In situ FT-IR studies confirm the reaction of ethylene molecules with the Brønsted acid sites associated with −Si−(OH)−Al− groups. In situ FT-IR results further suggest the occurrence of oligomerization of ethylene on the surface of H−ZSM-5. We speculate that the cracking of the oligomeric intermediates may lead to the formation of propylene. |
| ISSN : | 0888-5885 |
| En ligne : | http://pubs.acs.org/doi/abs/10.1021/ie901227p |
