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Heterogeneous cobalt−saponite catalyst for liquid phase air oxidation of p-cresol / Vikas S. Kshirsagar in Industrial & engineering chemistry research, Vol. 48 N° 21 (Novembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 21 (Novembre 2009) . - pp. 9423–9427 Titre : Heterogeneous cobalt−saponite catalyst for liquid phase air oxidation of p-cresol Type de document : texte imprimé Auteurs : Vikas S. Kshirsagar, Auteur ; Ajit C. Garade, Auteur ; Kashinath R. Patil, Auteur Année de publication : 2010 Article en page(s) : pp. 9423–9427 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Heterogeneous  Co−saponite  p-Cresol Résumé : Heterogeneous Co−saponite was found to be an efficient catalyst for the liquid phase oxidation of p-cresol under mild conditions. Divalent cobalt ions were found to be in both the tetrahedral and octahedral positions of the saponite clay. Studies on the effect of reaction parameters showed that the rate of reaction increased with increase in Co loading from 5 to 13% and then remained constant up to 30% of Co loading, while the rate of oxidation showed a first-order dependence on the partial pressure of oxygen up to 300 kPa. Results of oxidation experiments over Co−saponite, in an inert atmosphere, and the XPS studies suggest Mars−van Krevelen pathway operating, which involves lattice oxygen of Co−saponite in the liquid phase oxidation of p-cresol. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801941e [article] Heterogeneous cobalt−saponite catalyst for liquid phase air oxidation of p-cresol [texte imprimé] / Vikas S. Kshirsagar, Auteur ; Ajit C. Garade, Auteur ; Kashinath R. Patil, Auteur . - 2010 . - pp. 9423–9427. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 21 (Novembre 2009) . - pp. 9423–9427 Mots-clés : Heterogeneous  Co−saponite  p-Cresol Résumé : Heterogeneous Co−saponite was found to be an efficient catalyst for the liquid phase oxidation of p-cresol under mild conditions. Divalent cobalt ions were found to be in both the tetrahedral and octahedral positions of the saponite clay. Studies on the effect of reaction parameters showed that the rate of reaction increased with increase in Co loading from 5 to 13% and then remained constant up to 30% of Co loading, while the rate of oxidation showed a first-order dependence on the partial pressure of oxygen up to 300 kPa. Results of oxidation experiments over Co−saponite, in an inert atmosphere, and the XPS studies suggest Mars−van Krevelen pathway operating, which involves lattice oxygen of Co−saponite in the liquid phase oxidation of p-cresol. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801941e

MCM - 41 supported phosphotungstic acid for the hydroxyalkylation of phenol to phenolphthalein / Ajay Jha in Industrial & engineering chemistry research, Vol. 51 N° 10 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 10 (Mars 2012) . - pp. 3916–3922 Titre : MCM - 41 supported phosphotungstic acid for the hydroxyalkylation of phenol to phenolphthalein Type de document : texte imprimé Auteurs : Ajay Jha, Auteur ; Ajit C. Garade, Auteur ; Subhash P. Mirajkar, Auteur Année de publication : 2012 Article en page(s) : pp. 3916–3922 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Phosphotungstic  acid  Hydroxyalkylation Résumé : A novel application of phosphotungstic acid, H3PW12O40 (PWA) supported on MCM-41 molecular sieve as a solid acid catalyst has been demonstrated for the synthesis of phenolphthalein by hydroxyalkylation of phenol and phthalic anhydride. PWA/MCM-41 (20%) showed the highest activity as compared to that of parent PWA and MCM-41 individually, due to the excellent dispersion of PWA on MCM-41 leading to the redistribution of Bronsted and Lewis acid sites on MCM-41. The effect of PWA loading on phthalic anhydride conversion and phenolphthalein selectivity was also studied. All these prepared catalysts were characterized by XRD, N2 adsorption–desorption isotherm, pyridine-FTIR, and NH3-TPD. The effect of various reaction parameters, namely, mole ratios, catalyst concentration, temperature, reaction time, and percentage of PWA present in the catalysts on conversion and selectivity of products has been also investigated. The utility of 20% PWA/MCM-41 catalyst was established by its efficient activity for hydroxyalkylation of phenol and p-cresol with formaldehyde to the corresponding dihydroxydiarylmethane products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201989g [article] MCM - 41 supported phosphotungstic acid for the hydroxyalkylation of phenol to phenolphthalein [texte imprimé] / Ajay Jha, Auteur ; Ajit C. Garade, Auteur ; Subhash P. Mirajkar, Auteur . - 2012 . - pp. 3916–3922. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 10 (Mars 2012) . - pp. 3916–3922 Mots-clés : Phosphotungstic  acid  Hydroxyalkylation Résumé : A novel application of phosphotungstic acid, H3PW12O40 (PWA) supported on MCM-41 molecular sieve as a solid acid catalyst has been demonstrated for the synthesis of phenolphthalein by hydroxyalkylation of phenol and phthalic anhydride. PWA/MCM-41 (20%) showed the highest activity as compared to that of parent PWA and MCM-41 individually, due to the excellent dispersion of PWA on MCM-41 leading to the redistribution of Bronsted and Lewis acid sites on MCM-41. The effect of PWA loading on phthalic anhydride conversion and phenolphthalein selectivity was also studied. All these prepared catalysts were characterized by XRD, N2 adsorption–desorption isotherm, pyridine-FTIR, and NH3-TPD. The effect of various reaction parameters, namely, mole ratios, catalyst concentration, temperature, reaction time, and percentage of PWA present in the catalysts on conversion and selectivity of products has been also investigated. The utility of 20% PWA/MCM-41 catalyst was established by its efficient activity for hydroxyalkylation of phenol and p-cresol with formaldehyde to the corresponding dihydroxydiarylmethane products. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201989g