National Institute Of Materials Physics - Romania

Publications

170 articles found

141. Metal-triflate ionic liquid systems immobilized onto mesoporous MS41 materials as new and efficient catalysts for N-acylation

Authors: Coman, SM; Florea, M; Parvulescu, VI; David, V; Medvedovici, A; De Vos, D; Jacobs, PA; Poncelet, G; Grange, P

Published: JUL 25 2007, , DOI: 10.1016/j.jcat.2007.04.022

142. Ceria-based oxides as supports for LaCoO3 perovskite; catalysts for total oxidation of VOC

Authors: Alifanti, M; Florea, M; Parvulescu, VI

Published: JAN 31 2007, , DOI: 10.1016/j.apcatb.2005.10.037

143. Effect of nitridation on the electronic environment of vanadium in VAlO(N) powder catalysts, used for the ammoxidation of propane

Authors: Silversmit, G; Poelman, H; De Gryse, R; Bras, W; Nikitenko, S; Florea, M; Grange, P; Delsarte, S

Published: DEC 15 2006, , DOI: 10.1016/j.cattod.2006.07.013

144. In situ structural changes during toluene complete oxidation on supported EuCoO3 monitored with Eu-151 Mossbauer spectroscopy

Authors: Alifanti, M; Florea, M; Filotti, G; Kuncser, V; Cortes-Corberan, V; Parvulescu, VI

Published: SEP 30 2006, CATALYSIS TODAY, 117, 336, DOI: 10.1016/j.cattod.2006.05.036

Ceria-zirconia supported (10 and 20 wt.% EuCoO3) versus bulk EuCoO3 perovskite were prepared via citrate decomposition at 700 degrees C and tested for toluene complete oxidation. S-BET, XRD, XPS, H-2-TPD and in situ Eu-151 Mossbauer investigations were performed. Electron delocalization processes around the Eu cations are induced by the reaction, as proved via the evolution of the Mossbauer parameters. All characterization data indicate the formation of a well-dispersed EuCoO3 at the surface of Ce0.9Zr0.1O2 for the 10 wt.% loading and larger crystallite formation for 20 wt.% loading. In terms of intrinsic activity for toluene combustion, supported catalysts were more active than bulk EuCoO3. All structural changes during operation time are reversible. (C) 2006 Elsevier B.V. All rights reserved.

145. Understanding the role of nitridation in butan-1-ol and butan-2-ol dehydration mechanisms over oxynitrides

Authors: Delsarte, S; Florea, M; Mauge, F; Grange, P

Published: AUG 1 2006, , DOI: 10.1016/j.cattod.2006.01.033

146. High surface area Mo-V-Te-Nb-O catalysts: Preparation, characterization and catalytic behaviour in ammoxidation of propane

Authors: Florea, M; Mamede, AS; Eloy, P; Parvulescu, VI; Gaigneaux, EM

Published: MAR 15 2006, , DOI: 10.1016/j.cattod.2005.11.080

147. Effect of LaCoO3 perovskite deposition on ceria-based supports on total oxidation of VOC

Authors: Alifanti, M; Florea, M; Cortes-Corberan, V; Endruschat, U; Delmon, B; Parvulescu, VI

Published: MAR 15 2006, , DOI: 10.1016/j.cattod.2005.11.017

148. EPR and TEM characterization of electrolurninescent Alq(3)

Authors: Grecu, MN; Ghica, C; Mirea, A; Grecu, VV; Schwoerer, M

Published: 2006, ADVANCED MATERIALS FORUM III, PTS 1 AND 2, 514-516, 137, DOI: 10.4028/www.scientific.net/MSF.514-516.133

EPR and TEM investigations on sublimated solid Alq(3), [tris(8-hydroxyquinoline)aluminum(Ill)] are reported. Different paramagnetic centers in microcrystalline Alq3 fractions as synthesized and annealed are observed. Their nature, thermal treatment dependence, as well as correlation with the crystal structure are analyzed. The existence of randomly oriented triplets and quartets in annealed Alq3 fractions is evidenced from the temperature dependence of X- and Q-band EPR spectra. The spin Hamiltonian parameters are given and proposals for the model structures are made.

149. Preparation of Mo-V-Te-Nb mixed oxides using the template route

Authors: Florea, M; Gaigneaux, EM; Parvulescu, VI

Published: 2006, , DOI: 10.1016/S0167-2991(06)80979-1

150. Paramagnetic defect centres in crystalline Alq(3)

Authors: Grecu, MN; Mirea, A; Ghica, C; Colle, M; Schwoerer, M

Published: OCT 5 2005, JOURNAL OF PHYSICS-CONDENSED MATTER, 17, 6283, DOI: 10.1088/0953-8984/17/39/012

X- and Q-band electron paramagnetic resonance (EPR) investigation of different crystalline Alq(3) (tris(8-hydroxyquinoline)aluminium (III)) fractions formed by a train sublimation method are reported. Several paramagnetic defect centres corresponding to 1/2, 1, and 3/2 spin are observed at room temperature. Their intensity is dependent on the temperature, nature of the crystalline phase, and preparation conditions. Spectra simulation and analysis based on the spin Hamiltonian appropriate to a high spin system (S >=, 1) suggest the existence of randomly oriented triplets and quartets in annealed Alq(3) fractions. The crystalline Alq(3) phases responsible for the EPR powder spectra have been identified by transmission electron microscopy measurements performed on these sample fractions.