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Rhodium metal complex and hydrotalcite based environmentally friendly catalyst system for the selective synthesis of C8-aldehydes from propylene / Vivek K. Srivastava in Industrial & engineering chemistry research, Vol. 47 n°11 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3795–3803 Titre : Rhodium metal complex and hydrotalcite based environmentally friendly catalyst system for the selective synthesis of C8-aldehydes from propylene Type de document : texte imprimé Auteurs : Vivek K. Srivastava, Auteur ; Sumeet K. Sharma, Auteur ; Ram S. Shukla, Auteur ; Raksh V. Jasra, Auteur Année de publication : 2008 Article en page(s) : p. 3795–3803 Note générale : Bibliogr. p. 3802-3803 Langues : Anglais (eng) Mots-clés : Rhodium  complex;  Catalytic  activity;  Kinetic  profiles;  Reaction  rates Résumé : Catalytic activity of a novel catalyst [HFN + HT] containing a rhodium complex, HRh(CO)(PPh3)3 [HFN], and a solid base, hydrotalcite Mg1-xAlx(OH2)x+(CO32−)x/n·mH2O [HT], was evaluated for carrying out hydroformylation, aldol condensation, and hydrogenation in a single pot for the synthesis of C8-aldehydes, 2-ethylhexenal and 2-ethylhexanal, from propylene. In typical catalytic experiments conducted in a high-pressure reactor of 100 mL capacity, the selectivity for the formation of 2-ethylhexanal (54%) was found to be four times more than that of 2-ethylhexenal (13%) at 150 °C with employed partial pressures of propylene, carbon monoxide, and hydrogen at 10, 5, and 15 bar, respectively. Detailed investigations were performed on the effects of various reaction parameters, Mg/Al molar ratio (X) of [HT], amount of [HFN] complex, amount of [HT], and reaction temperature, on the formation of C8-aldehydes from propylene in a single pot. Under the employed reaction conditions, the maximum selectivity for 2-ethylhexanal was observed using hydrotalcite of Mg/Al molar ratio 3.5. Increasing the amounts of both [HFN] complex and [HT] favored the selectivities for the formation of 2-ethylhexanal up to certain amounts, and after that, on further increasing the amounts, the selectivities for the same were decreased. The kinetic profiles for the formation of various products with time and reaction rates were determined. For comparative studies, the kinetic profiles and reaction rates with the commercially employed catalyst, [HFN + KOH], were also determined under identical reaction conditions of [HFN + HT(3.5)], and the selectivity of 2-ethylhexanal was found to be almost identical at 7 h for the both systems. On the basis of experiments and kinetic profiles, reaction pathways are suggested for the formation of C8-aldehydes from propylene in a single pot. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071108r [article] Rhodium metal complex and hydrotalcite based environmentally friendly catalyst system for the selective synthesis of C8-aldehydes from propylene [texte imprimé] / Vivek K. Srivastava, Auteur ; Sumeet K. Sharma, Auteur ; Ram S. Shukla, Auteur ; Raksh V. Jasra, Auteur . - 2008 . - p. 3795–3803. Bibliogr. p. 3802-3803 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°11 (Juin 2008) . - p. 3795–3803 Mots-clés : Rhodium  complex;  Catalytic  activity;  Kinetic  profiles;  Reaction  rates Résumé : Catalytic activity of a novel catalyst [HFN + HT] containing a rhodium complex, HRh(CO)(PPh3)3 [HFN], and a solid base, hydrotalcite Mg1-xAlx(OH2)x+(CO32−)x/n·mH2O [HT], was evaluated for carrying out hydroformylation, aldol condensation, and hydrogenation in a single pot for the synthesis of C8-aldehydes, 2-ethylhexenal and 2-ethylhexanal, from propylene. In typical catalytic experiments conducted in a high-pressure reactor of 100 mL capacity, the selectivity for the formation of 2-ethylhexanal (54%) was found to be four times more than that of 2-ethylhexenal (13%) at 150 °C with employed partial pressures of propylene, carbon monoxide, and hydrogen at 10, 5, and 15 bar, respectively. Detailed investigations were performed on the effects of various reaction parameters, Mg/Al molar ratio (X) of [HT], amount of [HFN] complex, amount of [HT], and reaction temperature, on the formation of C8-aldehydes from propylene in a single pot. Under the employed reaction conditions, the maximum selectivity for 2-ethylhexanal was observed using hydrotalcite of Mg/Al molar ratio 3.5. Increasing the amounts of both [HFN] complex and [HT] favored the selectivities for the formation of 2-ethylhexanal up to certain amounts, and after that, on further increasing the amounts, the selectivities for the same were decreased. The kinetic profiles for the formation of various products with time and reaction rates were determined. For comparative studies, the kinetic profiles and reaction rates with the commercially employed catalyst, [HFN + KOH], were also determined under identical reaction conditions of [HFN + HT(3.5)], and the selectivity of 2-ethylhexanal was found to be almost identical at 7 h for the both systems. On the basis of experiments and kinetic profiles, reaction pathways are suggested for the formation of C8-aldehydes from propylene in a single pot. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071108r