Search

Your search keyword '"Wojcieszak, Robert"' showing total 419 results
Start Over Author "Wojcieszak, Robert"
419 results on '"Wojcieszak, Robert"'

151. Bimetallic Fe-Ni/SiO2 catalysts for furfural hydrogenation: identification of the interplay between Fe and Ni during deposition-precipitation and thermal treatments

Author

Shi, Dichao, Sébastien, Paul, Wojcieszak, Robert, Bagot, Paul A. J., Stievano, Lorenzo, Marceau, E., Constant, Anne, Lamic-Humblot, Anne-Félicie, Young, Q., Briois, Valérie, Peterson, Christi, Girardon, Jean-Sébastien, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Réactivité de Surface (LRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

152. High-Throughput Development of Non-Noble Metal-Based Catalysts for the Decarboxylation of Palmitic Acid into Pendecane

Author

Kiméné, Anouchka, Durlin, Claire, Simon, Olivier, Silva Vargas, Karen, Wojcieszak, Robert, Sébastien, Paul, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

153. Pt-Pd/TiO2 catalysts in glucose hydrogenation: looking for a bimetallic synergy

Author

Wojcieszak, Robert, Marques, Anderson, Camargo, Pedro, Sébastien, Paul, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

154. Preparation of transition metal (oxide) nanoparticles confined in the secondary pore network of mesoporous scaffolds using melt infiltration

Author

Chen, Shuo, Ciotonea, Carmen, Wojcieszak, Robert, Dumeignil, Franck, Royer, Sébastien, Dumitriu, Emil, Ungureanu, Adrian, Catrinescu, Cezar, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

155. Influence de la formulation de catalyseurs bimétalliques Fe-Ni/SiO2 sur la conversion du furfural en alcool furfurylique

Author

Shi, Dichao, Wojcieszak, Robert, Mamede, Anne-Sophie, Lamic-Humblot, Anne-Félicie, Sébastien, Paul, Marceau, E., Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Laboratoire de Réactivité de Surface (LRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2018

156. Influence of the formulation of bimetallic Fe-Ni/SiO2 catalysts on the conversion of furfural to furfuryl alcohol

Author

Shi, Dichao, Wojcieszak, Robert, Mamede, Anne-Sophie, Lamic-Humblot, Anne-Félicie, Sébastien, Paul, Marceau, E., Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2018

157. Novel AuxPdy@SiTi Nanomaterials for Base-Free Oxidation of Bio-Based Substrates

Author

Ferraz, Camila Palombo, Costa, Natália J. S., Rossi, Liane Marcia, Wojcieszak, Robert, Dumeignil, Franck, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

158. Supported gold nanoparticles: base-free oxidations for biomass upgrading

Author

Wojcieszak, Robert, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

160. Bimetallic Fe-Ni/SiO2 catalysts for furfural hydrogenation: Identification of the interplay between Fe and Ni during deposition-precipitation and thermal treatments

Author

Shi, Dichao, primary, Yang, Qifeng, additional, Peterson, Christi, additional, Lamic-Humblot, Anne-Félicie, additional, Girardon, Jean-Sébastien, additional, Griboval-Constant, Anne, additional, Stievano, Lorenzo, additional, Sougrati, Moulay T., additional, Briois, Valérie, additional, Bagot, Paul A.J., additional, Wojcieszak, Robert, additional, Paul, Sébastien, additional, and Marceau, Eric, additional

Published
2019
Full Text
View/download PDF

166. Challenges in Green processing and Process intensification

Author

Wojcieszak, Robert, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2017

167. One step sustainable synthesis of adipic acid

Author

Mazzi, Alberto, Paul, Sébastien, Cavani, Fabrizio, Wojcieszak, Robert, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2017

168. Strategies for biomass valorization. What are the potential chemicals and how to add value?

Author

Wojcieszak, Robert, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2017

170. Combining active phase and support optimization in MnO2-Au nanoflowers: Enabling high activities towards green oxidations

Author

da Silva, Anderson G.M., primary, Rodrigues, Thenner S., additional, Candido, Eduardo G., additional, de Freitas, Isabel C., additional, da Silva, Alisson H.M., additional, Fajardo, Humberto V., additional, Balzer, Rosana, additional, Gomes, Janaina F., additional, Assaf, Jose M., additional, de Oliveira, Daniela C., additional, Oger, Nicolas, additional, Paul, Sebastien, additional, Wojcieszak, Robert, additional, and Camargo, Pedro H.C., additional

Published
2018
Full Text
View/download PDF

176. From sequential chemoenzymatic synthesis to integrated hybrid catalysis: taking the best of both worlds to open up the scope of possibilities for a sustainable future

Author

Dumeignil, Franck, primary, Guehl, Marie, additional, Gimbernat, Alexandra, additional, Capron, Mickaël, additional, Ferreira, Nicolas Lopes, additional, Froidevaux, Renato, additional, Girardon, Jean-Sébastien, additional, Wojcieszak, Robert, additional, Dhulster, Pascal, additional, and Delcroix, Damien, additional

Published
2018
Full Text
View/download PDF

177. Conversion de biomasse cellulosique en énergie et produits et implications pour le climat et le développement durable

Author

Wojcieszak, Robert, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

178. Catalytic hydrogenation of CO2: a step towards liquid fuels

Author

Gonçalves, R. V., Vono, Lucas Lucchiari Ribeiro, Wojcieszak, Robert, Sato, C., Wender, Heberton, Teixeira-Neto, E., Rossi, Liane Marcia, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

179. Is the synergy between Pt and Pd in the green synthesis of methyl formate related to preparation method?

Author

Wojcieszak, Robert, Baldovino-Medrano, Víctor G., Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

180. Oleic acid derivates as templates for micro- and mesoporous materials synthesis

Author

Pirez, Cyril, Desset, Simon, Dumeignil, Franck, Wojcieszak, Robert, Katryniok, Benjamin, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

181. New trends in the production of green hydrocarbons from fatty acids via catalytic decarboxylation reactions

Author

Kimene, A., Simon, O., Durlin, C., Wojcieszak, Robert, Paul, Sébastien, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

186. 'Metallic Nanoparticles for Biomass Conversion to Highly Valued Chemicals'

Author

Wojcieszak, Robert, Rossi, Liane Marcia, Paul, Sébastien, Dumeignil, Franck, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2015

187. Katryniok, B

Author

Grasset, Fabien, Belliere-Baca, V., Araque-Marin, M., Paul, Sébastien, Dumeignil, Franck, Wojcieszak, Robert, Rey, Patrick, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Adisseo France S.A.S, Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)

Subjects
[CHIM.CATA]Chemical Sciences/Catalysis
Abstract

cited By 1; International audience

Published
2015

188. Artificial Neural Networks To Distinguish Charcoal from Eucalyptusand Native Forests Based on Their Mineral Components

Author

Ramalho, Fernanda Maria Guedes, Carvalho, Geila Santos, Hein, Paulo Ricardo Gherardi, Napoli, Alfredo, Wojcieszak, Robert, and Guilherme, Luiz Roberto Guimarães

Abstract

Charcoal is produced through the pyrolysis of wood. It is used as the main domestic energy source in many tropical countries from Africa and Asia, and it is used as a reductor product in the steel industry in Brazil. However, the indiscriminant use of wood from native forests is detrimental to sustainability. The development of rapid and efficient methodologies for distinguishing charcoal produced from native forest or Eucalyptusplantations, as found partially in Brazil, is essential to curb illegal charcoal transport and trade. The aim of this study was to distinguish charcoals from native or Eucalyptuswoods by using artificial neural networks (ANNs) based on their mineral composition. Specimens from Brazilian native woods (Apuleiasp., Cedrelasp., Aspidospermasp., Jacarandasp., Peltogynesp., Dipteryxsp., and Gochnatiasp.) and from Eucalyptussp. hybrid woods of commercial forest plantations were pyrolyzed at temperatures from 300 °C to 700 °C in order to simulate the actual pyrolysis conditions and species widely used illegally in southeastern Brazil. Charcoals composition and proportion of mineral elements were determined by X-ray fluorescence. The ANNs were trained based on the elemental composition of the charcoal specimens to classify the species and origin of the charcoals (i.e., native forest or Eucalyptus). The ANNs based on mineral element content yielded high percentage of correct classification for charcoal specimens by species (72% accuracy) or origin (97% accuracy) from an independent validation sample set.

Published
2020
Full Text
View/download PDF

190. Synergetic behavior of TiO2-supported Pd(z)Pt(1-z) catalysts in the green synthesis of methyl formate

Author

UCL - SST/IMCN/MOST - Molecules, Solids and Reactivity, Baldovino Medrano, Victor G., Pollefeyt, Glenn, Bliznuk, Vitaliy, Van Driessche, Iabel, Gaigneaux, Eric M., Ruiz, Patricio, Wojcieszak, Robert, UCL - SST/IMCN/MOST - Molecules, Solids and Reactivity, Baldovino Medrano, Victor G., Pollefeyt, Glenn, Bliznuk, Vitaliy, Van Driessche, Iabel, Gaigneaux, Eric M., Ruiz, Patricio, and Wojcieszak, Robert

Abstract

Methyl formate (MF) is a valuable platform molecule, the industrial production of which is far from being green. In this contribution, TiO2-supported Pd(z)Pt(1−z) catalysts were found to be effective in the green synthesis of methyl formate (MF)—at T=323 K and ambient pressure—through methanol (MeOH) oxidation. Two series of catalysts with similar bulk Pd/(Pd+Pt) molar ratios, z, were prepared; one by a water-in-oil microemulsion (MicE) method and the other by an incipient wetness impregnation (IWI). The MicE method led to more efficient catalysts owing to a weak influence of z on particle size distributions and nanoparticles composition. Pd(z)Pt(1−z)-MicE catalysts exhibited strong synergistic effects for MF production but weak synergistic effects for MeOH conversion. The catalytic performance of Pd(z)Pt(1−z)-MicE was superior to that of Pd(z)Pt(1−z)-IWI catalysts despite the latter displaying synergetic effects during the reaction. The catalytic behavior of TiO2-supported Pd(z)Pt(1−z) catalysts was explained from correlations between XRD, TEM, and X-ray photoelectron spectroscopy characterizations.

Published
2016

192. Dehydration of Lactic Acid: The State of The Art.

Author

Bonnotte, Thomas, Paul, Sébastien, Araque, Marcia, Wojcieszak, Robert, Dumeignil, Franck, and Katryniok, Benjamin

Subjects
LACTIC acid, ACRYLIC acid, DEHYDRATION reactions, ZEOLITES, SILICATE minerals
Abstract

Abstract: The dehydration of lactic acid to produce acrylic acid is a renewable alternative to the mostly used production of acrylic acid from propene. In this review, the recent developments and state of the art for the dehydration of lactic acid to acrylic acid are presented and critically commented. The most recent publications on the topic are discussed inetail with respect to the observed catalysts and process performance data. Among the different catalysts developed, three main groups can be distinguished: zeolites, sulphates, and phosphates. The latter, especially hydroxyapatites, have recently attracted the attention of academics in particular. The three families of catalysts are discussed and the recent developments and technical drawbacks in the gas phase dehydration are reported. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

196. Study of mesoporous CdS-quantum-dot-sensitized TiO2 films by using X-ray photoelectron spectroscopy and AFM

Author

UCL - SST/IMCN/MOST - Molecules, Solids and Reactivity, Ghazzal, Mohamed, Wojcieszak, Robert, Raj, Gijo, Gaigneaux, Eric M., UCL - SST/IMCN/MOST - Molecules, Solids and Reactivity, Ghazzal, Mohamed, Wojcieszak, Robert, Raj, Gijo, and Gaigneaux, Eric M.

Abstract

CdS quantum dots were grown on mesoporous TiO2 films by successive ionic layer adsorption and reaction processes in order to obtain CdS particles of various sizes. AFM analysis shows that the growth of the CdS particles is a two-step process. The first step is the formation of new crystallites at each deposition cycle. In the next step the pre-deposited crystallites grow to form larger aggregates. Special attention is paid to the estimation of the CdS particle size by X-ray photoelectron spectroscopy (XPS). Among the classical methods of characterization the XPS model is described in detail. In order to make an attempt to validate the XPS model, the results are compared to those obtained from AFM analysis and to the evolution of the band gap energy of the CdS nanoparticles as obtained by UV–vis spectroscopy. The results showed that XPS technique is a powerful tool in the estimation of the CdS particle size. In conjunction with these results, a very good correlation has been found between the number of deposition cycles and the particle size.

Published
2014

197. Oxidation of methanol to methyl formate over supported Pd nanoparticles: insights into the reaction mechanism at low temperature

Author

UCL - SST/IMCN/MOST - Molecules, Solids and Reactivity, Wojcieszak, Robert, Karelovic Burotto, Alejandro, Gaigneaux, Eric M., Ruiz, Patricio, UCL - SST/IMCN/MOST - Molecules, Solids and Reactivity, Wojcieszak, Robert, Karelovic Burotto, Alejandro, Gaigneaux, Eric M., and Ruiz, Patricio

Abstract

Pd nanoparticles supported on TiO2 and SiO2 (2 wt.%) were synthesized by the water-in-oil microemulsion method. The materials were characterized by standard physico-chemical methods (XRD, ICP, TEM, BET, XPS) and DRIFT in operando mode and tested in the gas-phase reaction of methanol oxidation. The direct formation of methyl formate (MF) from methanol was observed. Supported palladium catalysts produced methyl formate at low temperature (<100 °C) with high selectivity. At higher temperatures methyl formate is no longer formed and the total oxidation to CO2 occurred. The DRIFT-operando study confirmed that methanol is adsorbed mainly in two forms, the undissociated gaseous methanol (via H bond) and dissociatively adsorbed methoxy species (CH3O−) on the surface. Methyl formate is formed already at RT with the maximum at about 80 °C. The mechanism of the formation of methyl formate from methanol at low temperature is discussed

Published
2014

198. Study of Supported Nickel Catalysts Prepared by Aqueous Hydrazine Method. Hydrogenating Properties and Hydrogen Storage : Support Effect. Silver Additive Effect

Author

Wojcieszak, Robert, Structure et Réactivité des Systèmes Moléculaires Complexes (SRSMC), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université Henri Poincaré - Nancy 1, Mohammed El-Miloud Bettahar, and UL, Thèses

Subjects
Catalyseurs au nickel, [CHIM.OTHE] Chemical Sciences/Other, Nanoparticules, Supports de catalyseurs, Catalyseurs à base de métaux de transition, [CHIM.OTHE]Chemical Sciences/Other, Hydrogénation
Abstract

We have studied Ni or NiAg nanoparticles obtained by the reduction of nickel salts (acetate or nitrate) by hydrazine and deposited by simple or EDTA-double impregnation on various supports (g-Al2O3, amorphous or crystallized SiO2, Nb2O5, CeO2 and carbon). Prepared catalysts were characterized by different methods (XRD, XPS, low temperature adsorption and desorption of N2, FTIR and FTIR-Pyridine, TEM, STEM, EDS, H2-TPR, H2-adsorption, H2-TPD, isopropanol decomposition) and tested in the gas phase hydrogenation of benzene or as carbon materials in the hydrogen storage at room temperature and high pressure. The catalysts prepared exhibited better dispersion and activity than classical catalysts. TOF's of NiAg/SiO2 or Ni/carbon catalysts were similar to Pt catalysts in benzene hydrogenation. Differences in support acidity or preparation method and presence of Ag as metal additive play a crucial role in the chemical reduction of Ni by hydrazine and in the final properties of the materials. Ni/carbon catalysts could store significant amounts of hydrogen at room temperature and high pressure (0.53%/30 bars), probably through the hydrogen spillover effect., Nous avons étudié des nanoparticles de Ni ou de NiAg obtenus par la réduction de sels de nickel (acétate ou nitrate) par l'hydrazine et déposés par imprégnation simple ou EDTA-double sur de divers supports (g-Al2O3, SiO2 amorphe ou cristallisé, Nb2O5, CeO2 et carbone). Des catalyseurs préparés ont été caractérisés par différentes méthodes (DRX, XPS, adsorption et désorption de N2 à basse température, FTIR, TEM, STEM, EDS, H2-TPR, H2-adsorption, H2-TPD, décomposition de isopropanol) et examinés dans l'hydrogénation du benzène en phase gazeuse ou comme matériaux de carbone dans le stockage d'hydrogène à la température ambiante/haute pression. Les catalyseurs préparés ont montrés une meilleure dispersion et activité que les catalyseurs classiques. Les TOF des catalyseurs de NiAg/SiO2 ou de Ni/carbon étaient semblables aux catalyseurs de platine dans l'hydrogénation de benzène. Différences dans l'acidité de support ou la méthode de préparation et présence d'Ag comme métal additif jeu un rôle crucial dans la réduction chimique de Ni par l'hydrazine et dans les propriétés finales des matériaux. Les catalyseurs de Ni/carbon pourraient stocker des quantités significatives d'hydrogène à la température ambiante et à haute pression (0.53%/30 barre), probablement par l'effet de spillover d'hydrogène.

Published
2006

199. Catalyseurs de nickel Supportés Préparés par la Méthode de l'Hydrazine Aqueuse. Propriétés Hydrogénantes et Stockage d'Hydrogène : Effet du Support. Effet de l'Ajout d'Argent

Author

Wojcieszak, Robert, Structure et Réactivité des Systèmes Moléculaires Complexes (SRSMC), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université Henri Poincaré - Nancy 1, and Mohammed El-Miloud Bettahar

Subjects
Catalyseurs au nickel, Nanoparticules, Supports de catalyseurs, Catalyseurs à base de métaux de transition, [CHIM.OTHE]Chemical Sciences/Other, Hydrogénation
Abstract

We have studied Ni or NiAg nanoparticles obtained by the reduction of nickel salts (acetate or nitrate) by hydrazine and deposited by simple or EDTA-double impregnation on various supports (g-Al2O3, amorphous or crystallized SiO2, Nb2O5, CeO2 and carbon). Prepared catalysts were characterized by different methods (XRD, XPS, low temperature adsorption and desorption of N2, FTIR and FTIR-Pyridine, TEM, STEM, EDS, H2-TPR, H2-adsorption, H2-TPD, isopropanol decomposition) and tested in the gas phase hydrogenation of benzene or as carbon materials in the hydrogen storage at room temperature and high pressure. The catalysts prepared exhibited better dispersion and activity than classical catalysts. TOF's of NiAg/SiO2 or Ni/carbon catalysts were similar to Pt catalysts in benzene hydrogenation. Differences in support acidity or preparation method and presence of Ag as metal additive play a crucial role in the chemical reduction of Ni by hydrazine and in the final properties of the materials. Ni/carbon catalysts could store significant amounts of hydrogen at room temperature and high pressure (0.53%/30 bars), probably through the hydrogen spillover effect.; Nous avons étudié des nanoparticles de Ni ou de NiAg obtenus par la réduction de sels de nickel (acétate ou nitrate) par l'hydrazine et déposés par imprégnation simple ou EDTA-double sur de divers supports (g-Al2O3, SiO2 amorphe ou cristallisé, Nb2O5, CeO2 et carbone). Des catalyseurs préparés ont été caractérisés par différentes méthodes (DRX, XPS, adsorption et désorption de N2 à basse température, FTIR, TEM, STEM, EDS, H2-TPR, H2-adsorption, H2-TPD, décomposition de isopropanol) et examinés dans l'hydrogénation du benzène en phase gazeuse ou comme matériaux de carbone dans le stockage d'hydrogène à la température ambiante/haute pression. Les catalyseurs préparés ont montrés une meilleure dispersion et activité que les catalyseurs classiques. Les TOF des catalyseurs de NiAg/SiO2 ou de Ni/carbon étaient semblables aux catalyseurs de platine dans l'hydrogénation de benzène. Différences dans l'acidité de support ou la méthode de préparation et présence d'Ag comme métal additif jeu un rôle crucial dans la réduction chimique de Ni par l'hydrazine et dans les propriétés finales des matériaux. Les catalyseurs de Ni/carbon pourraient stocker des quantités significatives d'hydrogène à la température ambiante et à haute pression (0.53%/30 barre), probablement par l'effet de spillover d'hydrogène.

Published
2006

200. Ni-Ce intermetallic phases in CeO2-supported nickel catalysts synthesized by gamma-radiolysis

Author

Chettibi, S., Wojcieszak, Robert, Boudjennad, E., Belloni, J., Bettahar, M., Keghouche, N., Laboratoire de Chimie Physique D'Orsay (LCPO), and Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Published
2006

Catalog

Books, media, physical & digital resources
See catalog results