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Jacques C Vedrine - One of the best experts on this subject based on the ideXlab platform.
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part i catalyst characterisation
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, A Galtayries, Jacques C VedrineAbstract:Abstract Two series of Alkaline Earth Oxides (AEO) of Mg, Ca, and Sr doped with 5 mol% Nd2O3 have been synthesised by two procedures: (i) evaporation of nitrate solutions with subsequent nitrate decomposition (designated Ev) and (ii) sol–gel method (designated SG). The catalysts samples characterisation was performed by ICP chemical analysis, BET specific surface area measurement, FTIR spectroscopy, CO2 TPD, powder XRD, and XPS. The XRD data have shown presence of solid solutions of both Nd in AEO and of Alkaline Earth elements in Nd2O3. The structural defects that appeared under Nd incorporation into AEO lattice were studied by detailed XRD peak profiles analysis. They were agglomerated or dispersed, their relative amounts depending on the preparation procedure and on the Alkaline-Earth ion size match with Nd3+. The dispersed local defects were favored by the sol–gel method and by close cation radii dimensions, whereas Nd3+ agglomerates formed mainly on Mg-containing samples and were favored by evaporation. The catalyst basicity has been observed to follow the expected order Mg
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part ii catalytic properties
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, Lachezar A Petrov, Jacques C VedrineAbstract:Abstract Two series of Alkaline-Earth Oxides of Mg, Ca, and Sr, doped with 5 mol% Nd 2 O 3 and synthesised by two different procedures: (i) evaporation of nitrate aqueous solutions followed by nitrate decomposition and (ii) sol–gel technique, have been studied for propane oxidative dehydrogenation reaction. Solid solutions of both Nd in Alkaline-Earth Oxides and of Alkaline-Earth elements in Nd 2 O 3 were shown to be formed as a result of both preparation procedures. It was observed that Nd increased strongly propane conversion, while propene and ethene selectivity generally followed the catalyst basicity measured by CO 2 -TPD. The sol–gel preparation led to materials exhibiting enhanced alkene selectivity, higher basicity and higher content of structural defects. The selectivity was observed to increase with propane conversion at increased contact time at difference with what was usually reported for redox-type catalysts. The relationship between catalyst preparation method, solid solution formation, lattice structural defects, surface basicity, and catalytic performance has been discussed.
Bistra Savova - One of the best experts on this subject based on the ideXlab platform.
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part i catalyst characterisation
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, A Galtayries, Jacques C VedrineAbstract:Abstract Two series of Alkaline Earth Oxides (AEO) of Mg, Ca, and Sr doped with 5 mol% Nd2O3 have been synthesised by two procedures: (i) evaporation of nitrate solutions with subsequent nitrate decomposition (designated Ev) and (ii) sol–gel method (designated SG). The catalysts samples characterisation was performed by ICP chemical analysis, BET specific surface area measurement, FTIR spectroscopy, CO2 TPD, powder XRD, and XPS. The XRD data have shown presence of solid solutions of both Nd in AEO and of Alkaline Earth elements in Nd2O3. The structural defects that appeared under Nd incorporation into AEO lattice were studied by detailed XRD peak profiles analysis. They were agglomerated or dispersed, their relative amounts depending on the preparation procedure and on the Alkaline-Earth ion size match with Nd3+. The dispersed local defects were favored by the sol–gel method and by close cation radii dimensions, whereas Nd3+ agglomerates formed mainly on Mg-containing samples and were favored by evaporation. The catalyst basicity has been observed to follow the expected order Mg
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part ii catalytic properties
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, Lachezar A Petrov, Jacques C VedrineAbstract:Abstract Two series of Alkaline-Earth Oxides of Mg, Ca, and Sr, doped with 5 mol% Nd 2 O 3 and synthesised by two different procedures: (i) evaporation of nitrate aqueous solutions followed by nitrate decomposition and (ii) sol–gel technique, have been studied for propane oxidative dehydrogenation reaction. Solid solutions of both Nd in Alkaline-Earth Oxides and of Alkaline-Earth elements in Nd 2 O 3 were shown to be formed as a result of both preparation procedures. It was observed that Nd increased strongly propane conversion, while propene and ethene selectivity generally followed the catalyst basicity measured by CO 2 -TPD. The sol–gel preparation led to materials exhibiting enhanced alkene selectivity, higher basicity and higher content of structural defects. The selectivity was observed to increase with propane conversion at increased contact time at difference with what was usually reported for redox-type catalysts. The relationship between catalyst preparation method, solid solution formation, lattice structural defects, surface basicity, and catalytic performance has been discussed.
Nicolae Drăgan - One of the best experts on this subject based on the ideXlab platform.
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part i catalyst characterisation
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, A Galtayries, Jacques C VedrineAbstract:Abstract Two series of Alkaline Earth Oxides (AEO) of Mg, Ca, and Sr doped with 5 mol% Nd2O3 have been synthesised by two procedures: (i) evaporation of nitrate solutions with subsequent nitrate decomposition (designated Ev) and (ii) sol–gel method (designated SG). The catalysts samples characterisation was performed by ICP chemical analysis, BET specific surface area measurement, FTIR spectroscopy, CO2 TPD, powder XRD, and XPS. The XRD data have shown presence of solid solutions of both Nd in AEO and of Alkaline Earth elements in Nd2O3. The structural defects that appeared under Nd incorporation into AEO lattice were studied by detailed XRD peak profiles analysis. They were agglomerated or dispersed, their relative amounts depending on the preparation procedure and on the Alkaline-Earth ion size match with Nd3+. The dispersed local defects were favored by the sol–gel method and by close cation radii dimensions, whereas Nd3+ agglomerates formed mainly on Mg-containing samples and were favored by evaporation. The catalyst basicity has been observed to follow the expected order Mg
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part ii catalytic properties
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, Lachezar A Petrov, Jacques C VedrineAbstract:Abstract Two series of Alkaline-Earth Oxides of Mg, Ca, and Sr, doped with 5 mol% Nd 2 O 3 and synthesised by two different procedures: (i) evaporation of nitrate aqueous solutions followed by nitrate decomposition and (ii) sol–gel technique, have been studied for propane oxidative dehydrogenation reaction. Solid solutions of both Nd in Alkaline-Earth Oxides and of Alkaline-Earth elements in Nd 2 O 3 were shown to be formed as a result of both preparation procedures. It was observed that Nd increased strongly propane conversion, while propene and ethene selectivity generally followed the catalyst basicity measured by CO 2 -TPD. The sol–gel preparation led to materials exhibiting enhanced alkene selectivity, higher basicity and higher content of structural defects. The selectivity was observed to increase with propane conversion at increased contact time at difference with what was usually reported for redox-type catalysts. The relationship between catalyst preparation method, solid solution formation, lattice structural defects, surface basicity, and catalytic performance has been discussed.
Diana Filkova - One of the best experts on this subject based on the ideXlab platform.
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part i catalyst characterisation
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, A Galtayries, Jacques C VedrineAbstract:Abstract Two series of Alkaline Earth Oxides (AEO) of Mg, Ca, and Sr doped with 5 mol% Nd2O3 have been synthesised by two procedures: (i) evaporation of nitrate solutions with subsequent nitrate decomposition (designated Ev) and (ii) sol–gel method (designated SG). The catalysts samples characterisation was performed by ICP chemical analysis, BET specific surface area measurement, FTIR spectroscopy, CO2 TPD, powder XRD, and XPS. The XRD data have shown presence of solid solutions of both Nd in AEO and of Alkaline Earth elements in Nd2O3. The structural defects that appeared under Nd incorporation into AEO lattice were studied by detailed XRD peak profiles analysis. They were agglomerated or dispersed, their relative amounts depending on the preparation procedure and on the Alkaline-Earth ion size match with Nd3+. The dispersed local defects were favored by the sol–gel method and by close cation radii dimensions, whereas Nd3+ agglomerates formed mainly on Mg-containing samples and were favored by evaporation. The catalyst basicity has been observed to follow the expected order Mg
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part ii catalytic properties
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, Lachezar A Petrov, Jacques C VedrineAbstract:Abstract Two series of Alkaline-Earth Oxides of Mg, Ca, and Sr, doped with 5 mol% Nd 2 O 3 and synthesised by two different procedures: (i) evaporation of nitrate aqueous solutions followed by nitrate decomposition and (ii) sol–gel technique, have been studied for propane oxidative dehydrogenation reaction. Solid solutions of both Nd in Alkaline-Earth Oxides and of Alkaline-Earth elements in Nd 2 O 3 were shown to be formed as a result of both preparation procedures. It was observed that Nd increased strongly propane conversion, while propene and ethene selectivity generally followed the catalyst basicity measured by CO 2 -TPD. The sol–gel preparation led to materials exhibiting enhanced alkene selectivity, higher basicity and higher content of structural defects. The selectivity was observed to increase with propane conversion at increased contact time at difference with what was usually reported for redox-type catalysts. The relationship between catalyst preparation method, solid solution formation, lattice structural defects, surface basicity, and catalytic performance has been discussed.
Mălina Răileanu - One of the best experts on this subject based on the ideXlab platform.
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part i catalyst characterisation
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, A Galtayries, Jacques C VedrineAbstract:Abstract Two series of Alkaline Earth Oxides (AEO) of Mg, Ca, and Sr doped with 5 mol% Nd2O3 have been synthesised by two procedures: (i) evaporation of nitrate solutions with subsequent nitrate decomposition (designated Ev) and (ii) sol–gel method (designated SG). The catalysts samples characterisation was performed by ICP chemical analysis, BET specific surface area measurement, FTIR spectroscopy, CO2 TPD, powder XRD, and XPS. The XRD data have shown presence of solid solutions of both Nd in AEO and of Alkaline Earth elements in Nd2O3. The structural defects that appeared under Nd incorporation into AEO lattice were studied by detailed XRD peak profiles analysis. They were agglomerated or dispersed, their relative amounts depending on the preparation procedure and on the Alkaline-Earth ion size match with Nd3+. The dispersed local defects were favored by the sol–gel method and by close cation radii dimensions, whereas Nd3+ agglomerates formed mainly on Mg-containing samples and were favored by evaporation. The catalyst basicity has been observed to follow the expected order Mg
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neodymium doped Alkaline Earth Oxide catalysts for propane oxidative dehydrogenation part ii catalytic properties
2009Co-Authors: Bistra Savova, Diana Filkova, D Crisan, Maria Crisan, Mălina Răileanu, Nicolae Drăgan, Lachezar A Petrov, Jacques C VedrineAbstract:Abstract Two series of Alkaline-Earth Oxides of Mg, Ca, and Sr, doped with 5 mol% Nd 2 O 3 and synthesised by two different procedures: (i) evaporation of nitrate aqueous solutions followed by nitrate decomposition and (ii) sol–gel technique, have been studied for propane oxidative dehydrogenation reaction. Solid solutions of both Nd in Alkaline-Earth Oxides and of Alkaline-Earth elements in Nd 2 O 3 were shown to be formed as a result of both preparation procedures. It was observed that Nd increased strongly propane conversion, while propene and ethene selectivity generally followed the catalyst basicity measured by CO 2 -TPD. The sol–gel preparation led to materials exhibiting enhanced alkene selectivity, higher basicity and higher content of structural defects. The selectivity was observed to increase with propane conversion at increased contact time at difference with what was usually reported for redox-type catalysts. The relationship between catalyst preparation method, solid solution formation, lattice structural defects, surface basicity, and catalytic performance has been discussed.