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Biodiesel production by esterification of free fatty acids over 12-tungstophosphoric acid anchored to MCM-41 / Varsha Brahmkhatri in Industrial & engineering chemistry research, Vol. 50 N° 11 (Juin 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6620–6628 Titre : Biodiesel production by esterification of free fatty acids over 12-tungstophosphoric acid anchored to MCM-41 Type de document : texte imprimé Auteurs : Varsha Brahmkhatri, Auteur ; Anjali Patel, Auteur Année de publication : 2011 Article en page(s) : pp 6620–6628 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Biodiesel  fatty  acids Résumé : Heterogeneous acid catalyst comprising 12-tungstophosphoric acid (30%) and MCM-41 was synthesized and characterized by X-ray diffraction (XRD), surface area measurement (BET method), and solid state 29Si NMR. The use of synthesized catalyst was explored for biodiesel production by esterification of free fatty acid, palmitic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, and temperature were studied to optimize the conditions for maximum conversion. The catalyst shows high activity in terms of 100% conversion toward palmitic acid and a high turnover number, 1992. The kinetic studies as well as the Koros Nowak test were also carried out, and it was found that esterification of palmitic acid follows first order kinetics and the rates are not mass transfer limited. The excellent catalytic performance is attributed to the large surface area and pore diameter of the mesoporous support, MCM-41 as well as the Bronsted acid strength of TPA, as active sites. The catalyst shows the potential of being used as a recyclable catalytic material after simple regeneration without significant loss in conversion. As an application, preliminary studies were carried out for biodiesel production from waste cooking oil, as feedstock without any pretreatment, and with methanol over the present catalyst. Studies also reveal that the catalyst can be used for biodiesel production from waste cooking oil. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102066q [article] Biodiesel production by esterification of free fatty acids over 12-tungstophosphoric acid anchored to MCM-41 [texte imprimé] / Varsha Brahmkhatri, Auteur ; Anjali Patel, Auteur . - 2011 . - pp 6620–6628. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp 6620–6628 Mots-clés : Biodiesel  fatty  acids Résumé : Heterogeneous acid catalyst comprising 12-tungstophosphoric acid (30%) and MCM-41 was synthesized and characterized by X-ray diffraction (XRD), surface area measurement (BET method), and solid state 29Si NMR. The use of synthesized catalyst was explored for biodiesel production by esterification of free fatty acid, palmitic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, and temperature were studied to optimize the conditions for maximum conversion. The catalyst shows high activity in terms of 100% conversion toward palmitic acid and a high turnover number, 1992. The kinetic studies as well as the Koros Nowak test were also carried out, and it was found that esterification of palmitic acid follows first order kinetics and the rates are not mass transfer limited. The excellent catalytic performance is attributed to the large surface area and pore diameter of the mesoporous support, MCM-41 as well as the Bronsted acid strength of TPA, as active sites. The catalyst shows the potential of being used as a recyclable catalytic material after simple regeneration without significant loss in conversion. As an application, preliminary studies were carried out for biodiesel production from waste cooking oil, as feedstock without any pretreatment, and with methanol over the present catalyst. Studies also reveal that the catalyst can be used for biodiesel production from waste cooking oil. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102066q

Solvent free selective oxidation of styrene and benzyl alcohol to benzaldehyde over an eco - friendly and reusable catalyst, undecamolybdophosphate supported onto neutral alumina / Anjali Patel in Industrial & engineering chemistry research, Vol. 51 N° 2 (Janvier 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 732–740 Titre : Solvent free selective oxidation of styrene and benzyl alcohol to benzaldehyde over an eco - friendly and reusable catalyst, undecamolybdophosphate supported onto neutral alumina Type de document : texte imprimé Auteurs : Anjali Patel, Auteur ; Soyeb Pathan, Auteur Année de publication : 2012 Article en page(s) : pp. 732–740 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst  Oxidation Résumé : Supported undecamolybdophosphate was synthesized and characterized by various physicochemical techniques and successfully used for solvent free oxidation of styrene and of benzyl alcohol to benzaldehyde. Influence of the reaction parameters (molar ratio of substrate to H2O2, amount of the catalyst, reaction time, and reaction temperature) were studied. The catalyst was reused three times without any significant loss in the catalytic activity. FT-IR, XRD, and DRS of regenerated catalyst indicated that the catalyst was undegraded and stable after the reaction. The novelty of the work lies in obtaining a single selective product, benzaldehyde, as well as a high TON for the same, under mild conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476406 [article] Solvent free selective oxidation of styrene and benzyl alcohol to benzaldehyde over an eco - friendly and reusable catalyst, undecamolybdophosphate supported onto neutral alumina [texte imprimé] / Anjali Patel, Auteur ; Soyeb Pathan, Auteur . - 2012 . - pp. 732–740. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 732–740 Mots-clés : Catalyst  Oxidation Résumé : Supported undecamolybdophosphate was synthesized and characterized by various physicochemical techniques and successfully used for solvent free oxidation of styrene and of benzyl alcohol to benzaldehyde. Influence of the reaction parameters (molar ratio of substrate to H2O2, amount of the catalyst, reaction time, and reaction temperature) were studied. The catalyst was reused three times without any significant loss in the catalytic activity. FT-IR, XRD, and DRS of regenerated catalyst indicated that the catalyst was undegraded and stable after the reaction. The novelty of the work lies in obtaining a single selective product, benzaldehyde, as well as a high TON for the same, under mild conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476406

Supported undecaphosphotungstate / Pragati A Shringarpure in Industrial & engineering chemistry research, Vol. 50 N° 15 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9069-9076 Titre : Supported undecaphosphotungstate : an ecofriendly and efficient solid catalyst for nonsolvent liquid-phase aerobic epoxidation of alkenes Type de document : texte imprimé Auteurs : Pragati A Shringarpure, Auteur ; Anjali Patel, Auteur Année de publication : 2011 Article en page(s) : pp. 9069-9076 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Epoxidation  Aerobe  Liquid  phase  Catalyst Résumé : An ecofriendly solid catalytic system comprising undecaphosphotungstate and neutral alumina was found to be an efficient catalytic system for solvent-free liquid-phase aerobic epoxidation of alkenes under mild reaction conditions. The superiority of the present catalyst lies in achieving 85% conversion for cyclohexene with 100% selectivity toward cyclohexene oxide. Further, the catalyst can be regenerated and can be reused up to three cycles without any significant loss in the catalytic activity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395854 [article] Supported undecaphosphotungstate : an ecofriendly and efficient solid catalyst for nonsolvent liquid-phase aerobic epoxidation of alkenes [texte imprimé] / Pragati A Shringarpure, Auteur ; Anjali Patel, Auteur . - 2011 . - pp. 9069-9076. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9069-9076 Mots-clés : Epoxidation  Aerobe  Liquid  phase  Catalyst Résumé : An ecofriendly solid catalytic system comprising undecaphosphotungstate and neutral alumina was found to be an efficient catalytic system for solvent-free liquid-phase aerobic epoxidation of alkenes under mild reaction conditions. The superiority of the present catalyst lies in achieving 85% conversion for cyclohexene with 100% selectivity toward cyclohexene oxide. Further, the catalyst can be regenerated and can be reused up to three cycles without any significant loss in the catalytic activity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395854

Synthesis and Characterization of 12-Tungstosilicic Acid Anchored to MCM-41 as well as Its Use as Environmentally Benign Catalyst for Synthesis of Succinate and Malonate Diesters / Varsha Brahmkhatri in Industrial & engineering chemistry research, Vol. 50 N° 24 (Décembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13693–13702 Titre : Synthesis and Characterization of 12-Tungstosilicic Acid Anchored to MCM-41 as well as Its Use as Environmentally Benign Catalyst for Synthesis of Succinate and Malonate Diesters Type de document : texte imprimé Auteurs : Varsha Brahmkhatri, Auteur ; Anjali Patel, Auteur Année de publication : 2012 Article en page(s) : pp. 13693–13702 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Tungstosilicic  acid  Catalyst Résumé : 12-Tungstosilisic acid anchored to MCM-41 was synthesized and characterized by various physicochemical techniques such as thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), laser-Raman spectroscopy, diffuse reflectance spectroscopy (DRS), N2 adsorption–desorption, 29Si-magic-angle spinning (MAS) NMR, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The total acidity was determined by n-butyl amine titration. The types of acidic sites (acidic strength) were determined by potentiometric titration. The use of synthesized material was explored for esterification of diacarboxylic acids with butanol. Influence of various reaction parameters (catalyst concentration, acid/alcohol molar ratio and reaction time) on catalytic performance was studied. The catalyst shows high activity in terms of higher yields toward diesters, especially for dioctyl succinate and dioctyl malonate. The catalyst was also regenerated and reused for four cycles. All these characteristics imply the high potential of an environmentally benign catalyst for synthesis of succinate and malonate diesters. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201447y [article] Synthesis and Characterization of 12-Tungstosilicic Acid Anchored to MCM-41 as well as Its Use as Environmentally Benign Catalyst for Synthesis of Succinate and Malonate Diesters [texte imprimé] / Varsha Brahmkhatri, Auteur ; Anjali Patel, Auteur . - 2012 . - pp. 13693–13702. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13693–13702 Mots-clés : Tungstosilicic  acid  Catalyst Résumé : 12-Tungstosilisic acid anchored to MCM-41 was synthesized and characterized by various physicochemical techniques such as thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), laser-Raman spectroscopy, diffuse reflectance spectroscopy (DRS), N2 adsorption–desorption, 29Si-magic-angle spinning (MAS) NMR, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The total acidity was determined by n-butyl amine titration. The types of acidic sites (acidic strength) were determined by potentiometric titration. The use of synthesized material was explored for esterification of diacarboxylic acids with butanol. Influence of various reaction parameters (catalyst concentration, acid/alcohol molar ratio and reaction time) on catalytic performance was studied. The catalyst shows high activity in terms of higher yields toward diesters, especially for dioctyl succinate and dioctyl malonate. The catalyst was also regenerated and reused for four cycles. All these characteristics imply the high potential of an environmentally benign catalyst for synthesis of succinate and malonate diesters. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201447y