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Phenol hydroxylation over Cu - containing LDHs and their calcined forms / Churchil A. Antonyraj in Industrial & engineering chemistry research, Vol. 49 N° 13 (Juillet 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 13 (Juillet 2010) . - pp. 6020–6026 Titre : Phenol hydroxylation over Cu - containing LDHs and their calcined forms : profound cobivalent metal influence Type de document : texte imprimé Auteurs : Churchil A. Antonyraj, Auteur ; Mohini Gandhi, Auteur ; S. Kannan, Auteur Année de publication : 2010 Article en page(s) : pp. 6020–6026 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydroxylation  phenol Résumé : Copper containing layered double hydroxides (LDHs) with less than 1 atom % Cu along with different cobivalent ions such as magnesium, zinc, nickel or cobalt at (Cu+M(II))/Al atomic ratio 3.0 were synthesized. Calcination of these materials offered mixed metal oxides (refereed here as CLDHs) without any discrete copper oxide phase as confirmed by PXRD and STEM analysis. Hydroxylation of phenol to catechol (CAT) and hydroquinone (HQ) was carried out over both as-synthesized and calcined materials. Among the cobivalent ions, zinc containing samples both in the as-synthesized and calcined forms showed very high activity while cobalt showed the minimum. Variation of copper content for CuZnAl ternary system (0.009 atom % to 0.056 atom %) showed a maximum activity for the sample with 0.038 atom % (CuZnAl-5-CLDH). High activity was attributed to better dispersion of isolated copper species as inferred through TPR measurements. Highly active CuZnAl-5-CLDH can be reused up to three cycles without any significant change in the activity. No significant variation in the conversion was noted when the reaction was scaled up to 200 times over CuZnAl-5-CLDH renders the promise of exploring it to the next level. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100399j [article] Phenol hydroxylation over Cu - containing LDHs and their calcined forms : profound cobivalent metal influence [texte imprimé] / Churchil A. Antonyraj, Auteur ; Mohini Gandhi, Auteur ; S. Kannan, Auteur . - 2010 . - pp. 6020–6026. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 13 (Juillet 2010) . - pp. 6020–6026 Mots-clés : Hydroxylation  phenol Résumé : Copper containing layered double hydroxides (LDHs) with less than 1 atom % Cu along with different cobivalent ions such as magnesium, zinc, nickel or cobalt at (Cu+M(II))/Al atomic ratio 3.0 were synthesized. Calcination of these materials offered mixed metal oxides (refereed here as CLDHs) without any discrete copper oxide phase as confirmed by PXRD and STEM analysis. Hydroxylation of phenol to catechol (CAT) and hydroquinone (HQ) was carried out over both as-synthesized and calcined materials. Among the cobivalent ions, zinc containing samples both in the as-synthesized and calcined forms showed very high activity while cobalt showed the minimum. Variation of copper content for CuZnAl ternary system (0.009 atom % to 0.056 atom %) showed a maximum activity for the sample with 0.038 atom % (CuZnAl-5-CLDH). High activity was attributed to better dispersion of isolated copper species as inferred through TPR measurements. Highly active CuZnAl-5-CLDH can be reused up to three cycles without any significant change in the activity. No significant variation in the conversion was noted when the reaction was scaled up to 200 times over CuZnAl-5-CLDH renders the promise of exploring it to the next level. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100399j