National Institute Of Materials Physics - Romania

Publications

166 articles found

131. Iron oxide colloids and their heterogenization by silica sol-gel entrapment: Catalytic and magnetic properties

Authors: Neatu, F; Kraynov, A; D'Souza, L; Parvulescu, VI; Kranjc, K; Kocevar, M; Kuncser, V; Richards, R

Published: AUG 31 2008, APPLIED CATALYSIS A-GENERAL, 346, 35, DOI: 10.1016/j.apcata.2008.04.024

Fe3O4 colloids modified by the chiral ligand cinchonidine were prepared with the goal of obtaining a magnetic and catalytic nano-material and were subsequently embedded in silica to form a heterogeneous catalyst. The systems were characterized by TEM and XRD measurements, while the Mossbauer technique was applied for measuring the magnetic properties of the Fe3O4 colloids. The hyperfine magnetic field distribution was consistent with one type of Fe oxide, namely, the magnetite (Fe304). These colloids, both as 'quasi-homogenous catalysts' (or soluble heterogeneous catalysts) and embedded in silica (heterogeneous catalysts) were employed in the selective hydrogenolysis of complex bicyclo[2.2.2]oct-7-enes (bicyclo[2.2.2]oct-2-enes when unsubstituted). (C) 2008 Published by Elsevier B.V.

132. The impact of the "memory effect" on the catalytic activity of Mg/Al; Mg,Zn/Al; Mg/Al,Ga hydrotalcite-like compounds used as catalysts for cycloxene epoxidation

Authors: Angelescu, E; Pavel, OD; Birjega, R; Florea, M; Zavoianu, R

Published: JUN 15 2008, , DOI: 10.1016/j.apcata.2007.12.022

133. WO(x)-CeO(2) and WO(x)-Nb(2)O(5) catalysts deactivation during hexane isomerization

Authors: Mamede, AS; Payen, E; Granger, P; Florea, M; Parvulescu, VI

Published: MAY 2008, , DOI: 10.1002/aic.11468

134. Mo-V-M-O (M = Ni, Cu, Zn, Sb, Ta) MIXED METAL OXIDES PREPARED BY SOLID-SOLID REACTIONS FOR OXIDATIVE DEHYDROGENATION OF ISOBUTANE

Authors: Mitran, G; Marcu, IC; Florea, M; Sandulescu, I

Published: MAY 2008, , DOI:

135. Plasma-assisted catalysis total oxidation of trichloroethylene over gold nano-particles embedded in SBA-15 catalysts

Authors: Magureanu, M; Mandache, NB; Hu, JC; Richards, R; Florea, M; Parvulescu, VI

Published: NOV 15 2007, , DOI: 10.1016/j.apcatb.2007.05.030

136. Acylation of different amino derivatives with fatty acids on UL-MFI-type catalysts

Authors: Musteata, M; Musteata, V; Dinu, A; Florea, M; Hoang, VT; Trong-On, D; Kaliaguine, S; Parvulescu, VI

Published: NOV 2007, , DOI: 10.1351/pac200779112059

137. 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

138. 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

139. 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

140. 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.