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Effect of alkaline treatment on the catalytic performance of ZSM-5 catalyst in pyridine and picolines synthesis / Jin Fang in Industrial & engineering chemistry research, Vol. 48 N°4 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - pp. 1873–1879 Titre : Effect of alkaline treatment on the catalytic performance of ZSM-5 catalyst in pyridine and picolines synthesis Type de document : texte imprimé Auteurs : Jin Fang, Auteur ; Ye Tian, Auteur ; Yongdan Li, Auteur Année de publication : 2009 Article en page(s) : pp. 1873–1879 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Alkaline  treatment  ZSM-5  catalyst  Pyridine  Picolines  Extra-framework  aluminum Résumé : An alkaline treatment is employed for tailoring a commercial H-ZSM-5 to produce a catalyst for the synthesis of pyridine and picolines. The most significant consequence of the alkaline treatment was desilication. However, it is accompanied by extraction of aluminum and formation of extra-framework aluminum (Alef) and amorphous alumina. Slit-shaped intracrystaline mesopores and macropores form. Because of the decrease in the Si/Al ratio in the zeolite framework and the formation of Alef and amorphous alumina, the number of strong acid sites decreases and that of weak acid sites increases. The ratio of Lewis acids to Brönsted acids (L/B) also increases. We note that the induced hierarchical pores and the change of acid strength distribution increase the stability of the catalyst, and the increased L/B causes an increase in the initial yield and comparative selectivity for pyridine and a decrease in those properties for 3-picoline. Coking leads to a gradual deactivation and affects product selectivity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8014457 [article] Effect of alkaline treatment on the catalytic performance of ZSM-5 catalyst in pyridine and picolines synthesis [texte imprimé] / Jin Fang, Auteur ; Ye Tian, Auteur ; Yongdan Li, Auteur . - 2009 . - pp. 1873–1879. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - pp. 1873–1879 Mots-clés : Alkaline  treatment  ZSM-5  catalyst  Pyridine  Picolines  Extra-framework  aluminum Résumé : An alkaline treatment is employed for tailoring a commercial H-ZSM-5 to produce a catalyst for the synthesis of pyridine and picolines. The most significant consequence of the alkaline treatment was desilication. However, it is accompanied by extraction of aluminum and formation of extra-framework aluminum (Alef) and amorphous alumina. Slit-shaped intracrystaline mesopores and macropores form. Because of the decrease in the Si/Al ratio in the zeolite framework and the formation of Alef and amorphous alumina, the number of strong acid sites decreases and that of weak acid sites increases. The ratio of Lewis acids to Brönsted acids (L/B) also increases. We note that the induced hierarchical pores and the change of acid strength distribution increase the stability of the catalyst, and the increased L/B causes an increase in the initial yield and comparative selectivity for pyridine and a decrease in those properties for 3-picoline. Coking leads to a gradual deactivation and affects product selectivity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8014457