National Institute Of Materials Physics - Romania

Publications

163 articles found

151. Influence of the nitrogen content on butan-1-ol and butan-2-ol dehydration properties of nitrided phosphates

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

Published: MAY-JUN 2004, , DOI:

152. Influence of the preparation conditions on the physico-chemical and catalytic properties of a vanadium-aluminum oxynitride propane ammoxidation catalyst

Authors: Silvy, RP; Blangenois, N; Florea, M; Grange, P; Cadus, L; Barbero, B

Published: MAY-JUN 2004, , DOI:

153. Influence of the reaction conditions on the activity properties of vanadium-aluminium oxynitride propane ammoxidation catalyst

Authors: Florea, M; Silvy, RP; Grange, P

Published: DEC 8 2003, , DOI: 10.1016/S0926-860X(03)00591-X

154. Propane ammoxidation catalyst based on vanadium-aluminum oxynitride

Authors: Silvy, RP; Florea, M; Blangenois, N; Grange, P

Published: AUG 2003, , DOI: 10.1002/aic.690490830

155. New class of catalysts for the propane ammoxidation process based on vanadium aluminum oxynitrides

Authors: Florea, M; Prady-Silvy, R; Grange, P

Published: APR 2003, , DOI: 10.1023/A:1022857211248

156. Ru-MCM-41 catalysts for diastereoselective hydrogenation

Authors: Florea, M; Sevinci, M; Parvulescu, VI; Lemay, G; Kaliaguine, S

Published: JUN 2001, , DOI: 10.1016/S1387-1811(01)00224-4

157. Low metal loading Ru-MCM-41 stereocontrolled hydrogenation of prostaglandin intermediates

Authors: Coman, S; Florea, M; Cocu, F; Parvulescu, VI; Jacobs, PA; Danumah, C; Kaliaguine, S

Published: NOV 7 1999, , DOI: 10.1039/a907119i

158. A green way for pyruvic acid synthesis from biomass-derived L-malic acid on tetrahedral versus octahedral cobalt sites/hematite

Authors: Mitran, G; Urda, A; Pavel, OD; Neatu, S; Florea, M; Neatu, F

Published: , BIOMASS CONVERSION AND BIOREFINERY, DOI:

A series of cobalt-iron mixed oxides, CoxFe3-xO4 (x = 0; 0.05; 0.1; 0.15), were synthesized by coprecipitation and tested for oxidative decarboxylation of malic acid to pyruvic or malonic acid. The characterization of catalysts was performed by different techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFT) and Ultraviolet-visible spectroscopy (UV-Vis). Among studied catalysts, Co0.15Fe2.85O4 sample (denoted Co3Fe) showed the highest malic acid conversion in oxidative decarboxylation reaction as well as the highest pyruvic acid yield. This behavior can be due to the fact that this sample has the highest content of tetrahedral Co2+ that replaces Fe3+ from octahedral position that determine an increased number of defects that play a crucial role for the malic acid conversion.

159. Structural and Optical Investigations of Ce3+/Mn2+-Doped LaPO4 Phosphors

Authors: Aitmellal, O; Oufni, L; Messous, MY; Neatu, F; Florea, M; Neatu, S; Rostas, AM; Secu, M

Published: , JOURNAL OF ELECTRONIC MATERIALS, DOI: 10.1007/s11664-020-08678-7

Lanthanum orthophosphate (LaPO4) and La0.95-xCe0.05MnxPO4 (x = 0.00, 0.03, 0.10) phosphors were synthesized by a simple and cost-efficient co-precipitation method and the formation of LaPO4 nanorods with a monoclinic P21/n crystal structure was observed. X-ray diffraction pattern analysis indicated a slight distortion of the LaPO4 crystalline structure and an increase of the lattice strain as a consequence of the Mn2+ and Ce3+ dopants incorporation in the host matrix. Scanning electron microscopy revealed that the microstructure of all powders consists of agglomerations of nanorods, which are around 17 +/- 3 nm in diameter and length ranging from 100 nm to 300 nm. Electron paramagnetic resonance measurements have indicated the presence of Mn2+ in isolated species, but also as agglomerates. Ce3+ and Mn2+ doping of LaPO4 resulted also in a decrease of the band gap up to 4.70 eV compared to the un-doped sample. Because of an energy transfer effect from Ce3+ to Mn2+ ions, green emission of Mn2+ ions at around 550 nm was observed upon 275 nm excitation.

160.

Authors: Neatu, S; Neatu, F; Diculescu, VC; Trandafir, MM; Petr

Published: , , DOI: