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Formation of carbon nanofibers from supported Pt catalysts through catalytic chemical vapor deposition from acetylene / Qilong Chen 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. 9034–9042 Titre : Formation of carbon nanofibers from supported Pt catalysts through catalytic chemical vapor deposition from acetylene Type de document : texte imprimé Auteurs : Qilong Chen, Auteur ; Jia Wang, Auteur ; Feng Li, Auteur Année de publication : 2011 Article en page(s) : pp. 9034–9042 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Chemical  vapor  deposition  Catalytic  reaction  Catalyst Résumé : Carbon nanofibers (CNFs) were synthesized by catalytic chemical vapor deposition from acetylene from a series of supported Pt catalysts derived from Pt-containing Mg–Al layered double hydroxide precursors. The materials were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, temperature programmed reduction, low-temperature N2 adsorption–desorption experiments, X-ray photoelectron spectroscopy, and Raman spectroscopy. The effects of reaction temperature and Pt content on the morphologies and microstructures of CNFs were investigated. The results revealed that the reaction temperature of 600 °C was appropriate for the growth of uniform CNFs with regular shape. Furthermore, the structural defects and the diameters of CNFs were reduced with the increasing Pt content, which is attributable to the high dispersion of smaller Pt nanoparticles as well as the quick deposition rate of carbon atoms on active metal particles. The present work developed an additional approach to optimize the growth of CNFs. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395850 [article] Formation of carbon nanofibers from supported Pt catalysts through catalytic chemical vapor deposition from acetylene [texte imprimé] / Qilong Chen, Auteur ; Jia Wang, Auteur ; Feng Li, Auteur . - 2011 . - pp. 9034–9042. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9034–9042 Mots-clés : Chemical  vapor  deposition  Catalytic  reaction  Catalyst Résumé : Carbon nanofibers (CNFs) were synthesized by catalytic chemical vapor deposition from acetylene from a series of supported Pt catalysts derived from Pt-containing Mg–Al layered double hydroxide precursors. The materials were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, temperature programmed reduction, low-temperature N2 adsorption–desorption experiments, X-ray photoelectron spectroscopy, and Raman spectroscopy. The effects of reaction temperature and Pt content on the morphologies and microstructures of CNFs were investigated. The results revealed that the reaction temperature of 600 °C was appropriate for the growth of uniform CNFs with regular shape. Furthermore, the structural defects and the diameters of CNFs were reduced with the increasing Pt content, which is attributable to the high dispersion of smaller Pt nanoparticles as well as the quick deposition rate of carbon atoms on active metal particles. The present work developed an additional approach to optimize the growth of CNFs. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395850

Structure and catalytic property of Li–Al metal oxides from layered double hydroxide precursors prepared via a facile solution route / Jia Wang in Industrial & engineering chemistry research, Vol. 50 N° 12 (Juin 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp 7120–7128 Titre : Structure and catalytic property of Li–Al metal oxides from layered double hydroxide precursors prepared via a facile solution route Type de document : texte imprimé Auteurs : Jia Wang, Auteur ; Zhiyi Lei, Auteur ; Hua Qin, Auteur Année de publication : 2011 Article en page(s) : pp 7120–7128 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Precursor  Catalytic  reaction Résumé : This paper presents the synthesis of Li–Al mixed metal oxides from Li–Al layered double hydroxides (LiAl-LDHs) by using a novel separate nucleation and solvothermal aging steps method. The physicochemical properties of as-synthesized LiAl-LDHs and resulting calcined products at 600 °C were investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), simultaneous thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscope (SEM), and low-temperature nitrogen adsorption–desorption experiments. The results indicated that uniform LiAl-LDH particles with smaller sizes were obtained by using ethanol as solvent in the aging step, in contrast with those by using water and water/ethanol mixture. Especially, after calcination, the resulting mixed metal oxides showed variable surface basicities, which were strongly dependent on their crystallite sizes and surface areas. When used as solid base catalysts for the Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate, the mixed metal oxides with more strong basic sites exhibited a higher catalytic activity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239025 [article] Structure and catalytic property of Li–Al metal oxides from layered double hydroxide precursors prepared via a facile solution route [texte imprimé] / Jia Wang, Auteur ; Zhiyi Lei, Auteur ; Hua Qin, Auteur . - 2011 . - pp 7120–7128. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp 7120–7128 Mots-clés : Precursor  Catalytic  reaction Résumé : This paper presents the synthesis of Li–Al mixed metal oxides from Li–Al layered double hydroxides (LiAl-LDHs) by using a novel separate nucleation and solvothermal aging steps method. The physicochemical properties of as-synthesized LiAl-LDHs and resulting calcined products at 600 °C were investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), simultaneous thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscope (SEM), and low-temperature nitrogen adsorption–desorption experiments. The results indicated that uniform LiAl-LDH particles with smaller sizes were obtained by using ethanol as solvent in the aging step, in contrast with those by using water and water/ethanol mixture. Especially, after calcination, the resulting mixed metal oxides showed variable surface basicities, which were strongly dependent on their crystallite sizes and surface areas. When used as solid base catalysts for the Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate, the mixed metal oxides with more strong basic sites exhibited a higher catalytic activity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239025

Synthesis, characterization, and catalytic performance of highly dispersed supported nickel catalysts from Ni – Al layered double hydroxides / Jia Wang 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. 13717–13726 Titre : Synthesis, characterization, and catalytic performance of highly dispersed supported nickel catalysts from Ni – Al layered double hydroxides Type de document : texte imprimé Auteurs : Jia Wang, Auteur ; Guoli Fan, Auteur ; Hui Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 13717–13726 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalysts  Hydroxides Résumé : Highly dispersed nickel nanoparticles were successfully prepared by reduction of Ni–Al layered double hydroxide precursor (NiAl-LDH) supported on nitric acid modified carbon nanotubes (HCNTs). The physicochemical properties of materials were investigated by powder X-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed decomposition (TPDE), temperature programmed desorption (TPD), transmission electron microscopy (TEM), low-temperature nitrogen adsorption–desorption experiments, and X-ray photoelectron spectroscopy (XPS). The results revealed that in the synthesis process of NiAl-LDH and HCNTs composite, l-cysteine could improve the attachment of NiAl-LDH on the HCNTs as bridging linker and inhibit the growth of NiAl-LDH crystallites, thus leading to the formation of highly dispersed and uniform Ni nanoparticles with the small particle sizes. Compared with HCNTs-supported Ni catalyst prepared without the addition of l-cysteine, this highly dispersed Ni catalyst exhibited enhanced catalytic performance in liquid phase hydrogenation of o-chloronitrobenzene to o-chloroaniline. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2015087 [article] Synthesis, characterization, and catalytic performance of highly dispersed supported nickel catalysts from Ni – Al layered double hydroxides [texte imprimé] / Jia Wang, Auteur ; Guoli Fan, Auteur ; Hui Wang, Auteur . - 2012 . - pp. 13717–13726. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13717–13726 Mots-clés : Catalysts  Hydroxides Résumé : Highly dispersed nickel nanoparticles were successfully prepared by reduction of Ni–Al layered double hydroxide precursor (NiAl-LDH) supported on nitric acid modified carbon nanotubes (HCNTs). The physicochemical properties of materials were investigated by powder X-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed decomposition (TPDE), temperature programmed desorption (TPD), transmission electron microscopy (TEM), low-temperature nitrogen adsorption–desorption experiments, and X-ray photoelectron spectroscopy (XPS). The results revealed that in the synthesis process of NiAl-LDH and HCNTs composite, l-cysteine could improve the attachment of NiAl-LDH on the HCNTs as bridging linker and inhibit the growth of NiAl-LDH crystallites, thus leading to the formation of highly dispersed and uniform Ni nanoparticles with the small particle sizes. Compared with HCNTs-supported Ni catalyst prepared without the addition of l-cysteine, this highly dispersed Ni catalyst exhibited enhanced catalytic performance in liquid phase hydrogenation of o-chloronitrobenzene to o-chloroaniline. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2015087