Corina Mihut - Academia.edu (original) (raw)
Papers by Corina Mihut
Langmuir, 2004
A series of bimetallic Al2O3-supported Rh-Ge catalysts was prepared by surface redox reactions un... more A series of bimetallic Al2O3-supported Rh-Ge catalysts was prepared by surface redox reactions under controlled hydrogen atmosphere. The surface properties of these catalysts were probed via in-situ FTIR spectroscopic studies of adsorbed CO and were compared to those of monometallic Rh catalysts that had undergone similar treatments. The results indicate that Ge addition results in the formation and stabilization of smaller rhodium ensembles at the expense of larger Rh0 surfaces. A charge-transfer mechanism from Ge to Rh is also inferred by the IR results for the high Ge loading samples. Air exposure of the catalysts leads to an irreversible segregation of the two metals and formation of large Rh crystallites.
Dierent mechanisms have been proposed in the literature for the selective catalytic reduction of ... more Dierent mechanisms have been proposed in the literature for the selective catalytic reduction of NO by hydrocarbons (and in particular by propane and propylene) over supported Pt catalysts. This manuscript reviews the available experimental evidence in support of a scheme involving the initial partial oxidation of the hydrocarbon and the subsequent formation of a surface cyanide or isocyanate intermediate. Furthermore, we present results of reaction kinetics analyses which indicate that such a reaction scheme can describe the available kinetic data at a quantitative level.
Journal of Catalysis, 2002
Silica-supported bimetallic Pt–Au catalysts prepared via different synthetic routes have been inv... more Silica-supported bimetallic Pt–Au catalysts prepared via different synthetic routes have been investigated in terms of their structural properties, adsorption of CO, and catalytic activity for the selective catalytic reduction of NO by propylene, the oxidation of propylene in the absence of NO, and the 16O/18O homoexchange reaction. Catalysts prepared by incipient wetness impregnation from individual Pt and Au precursors exhibited
Topics in Catalysis, 2000
Platinum-and iridium-based catalysts are the most active ones among noble metals for the selectiv... more Platinum-and iridium-based catalysts are the most active ones among noble metals for the selective catalytic reduction of NO by hydrocarbons (HC-SCR). Yet, the level of our understanding of the behavior of these two metals varies greatly. From the early stages of the research efforts in the HC-SCR field Pt-based catalysts were identified as ''promising'' and have been studied extensively for this application. Subsequently, there is a substantial body of literature focusing on the catalytic performance of such systems, as well as on the fundamental chemistry taking place on their surface under HC-SCR conditions. A fairly good understanding of the behavior of such catalysts has been developed and different reaction mechanisms have been proposed and debated extensively. In contrast, limited information is available regarding the properties and HC-SCR behavior of Ir-based catalysts. Recent reports have demonstrated advantages in the HC-SCR performance of such catalysts and have documented substantial iridium particle size, support and promoter effects.
Polymer Engineering & Science, 2001
... Review: Recycling of Nybn From Carpet Waste ... Polyamides that have been produced from a sin... more ... Review: Recycling of Nybn From Carpet Waste ... Polyamides that have been produced from a single monomer (nylon 6) are preferred, although mixtures of polymers can also be depolymerized As claimed by the patent, this invention is suitable for polymers in various forms such ...
Langmuir, 2004
A series of bimetallic Al2O3-supported Rh-Ge catalysts was prepared by surface redox reactions un... more A series of bimetallic Al2O3-supported Rh-Ge catalysts was prepared by surface redox reactions under controlled hydrogen atmosphere. The surface properties of these catalysts were probed via in-situ FTIR spectroscopic studies of adsorbed CO and were compared to those of monometallic Rh catalysts that had undergone similar treatments. The results indicate that Ge addition results in the formation and stabilization of smaller rhodium ensembles at the expense of larger Rh0 surfaces. A charge-transfer mechanism from Ge to Rh is also inferred by the IR results for the high Ge loading samples. Air exposure of the catalysts leads to an irreversible segregation of the two metals and formation of large Rh crystallites.
Journal of Catalysis, 2002
Catal Commun, 2002
The selective catalytic reduction of nitric oxide by propylene in the presence of excess oxygen h... more The selective catalytic reduction of nitric oxide by propylene in the presence of excess oxygen has been investigated over a series of silica supported Pt and PtAAu catalysts. Cluster-derived catalysts were prepared by wet impregnation using a Pt 2 Au 4 ðCBC t BuÞ 8 organometallic cluster precursor, and compared to catalysts obtained by incipient wetness impregnation using individual Pt and Au salts. The addition of Au by co-impregnation resulted only to a small shift (20-25°C) in the light-off of propylene towards higher temperatures. A markedly different catalytic behavior was observed in the case of cluster-derived catalysts, where a 150°C delay was observed both in the temperature of maximum NO reduction and the light-off of propylene in the presence and in the absence of NO. Most importantly, the selectivity towards N 2 increased by 50% compared to the monometallic Pt catalysts. The results of characterization studies indicate that the monometallic Pt=SiO 2 and the co-impregnated PtAAu=SiO 2 samples have similar metal particle sizes. A more narrow particle size distribution was observed with the cluster-derived bimetallic sample. Ó
Langmuir, 2004
A series of bimetallic Al2O3-supported Rh-Ge catalysts was prepared by surface redox reactions un... more A series of bimetallic Al2O3-supported Rh-Ge catalysts was prepared by surface redox reactions under controlled hydrogen atmosphere. The surface properties of these catalysts were probed via in-situ FTIR spectroscopic studies of adsorbed CO and were compared to those of monometallic Rh catalysts that had undergone similar treatments. The results indicate that Ge addition results in the formation and stabilization of smaller rhodium ensembles at the expense of larger Rh0 surfaces. A charge-transfer mechanism from Ge to Rh is also inferred by the IR results for the high Ge loading samples. Air exposure of the catalysts leads to an irreversible segregation of the two metals and formation of large Rh crystallites.
Dierent mechanisms have been proposed in the literature for the selective catalytic reduction of ... more Dierent mechanisms have been proposed in the literature for the selective catalytic reduction of NO by hydrocarbons (and in particular by propane and propylene) over supported Pt catalysts. This manuscript reviews the available experimental evidence in support of a scheme involving the initial partial oxidation of the hydrocarbon and the subsequent formation of a surface cyanide or isocyanate intermediate. Furthermore, we present results of reaction kinetics analyses which indicate that such a reaction scheme can describe the available kinetic data at a quantitative level.
Journal of Catalysis, 2002
Silica-supported bimetallic Pt–Au catalysts prepared via different synthetic routes have been inv... more Silica-supported bimetallic Pt–Au catalysts prepared via different synthetic routes have been investigated in terms of their structural properties, adsorption of CO, and catalytic activity for the selective catalytic reduction of NO by propylene, the oxidation of propylene in the absence of NO, and the 16O/18O homoexchange reaction. Catalysts prepared by incipient wetness impregnation from individual Pt and Au precursors exhibited
Topics in Catalysis, 2000
Platinum-and iridium-based catalysts are the most active ones among noble metals for the selectiv... more Platinum-and iridium-based catalysts are the most active ones among noble metals for the selective catalytic reduction of NO by hydrocarbons (HC-SCR). Yet, the level of our understanding of the behavior of these two metals varies greatly. From the early stages of the research efforts in the HC-SCR field Pt-based catalysts were identified as ''promising'' and have been studied extensively for this application. Subsequently, there is a substantial body of literature focusing on the catalytic performance of such systems, as well as on the fundamental chemistry taking place on their surface under HC-SCR conditions. A fairly good understanding of the behavior of such catalysts has been developed and different reaction mechanisms have been proposed and debated extensively. In contrast, limited information is available regarding the properties and HC-SCR behavior of Ir-based catalysts. Recent reports have demonstrated advantages in the HC-SCR performance of such catalysts and have documented substantial iridium particle size, support and promoter effects.
Polymer Engineering & Science, 2001
... Review: Recycling of Nybn From Carpet Waste ... Polyamides that have been produced from a sin... more ... Review: Recycling of Nybn From Carpet Waste ... Polyamides that have been produced from a single monomer (nylon 6) are preferred, although mixtures of polymers can also be depolymerized As claimed by the patent, this invention is suitable for polymers in various forms such ...
Langmuir, 2004
A series of bimetallic Al2O3-supported Rh-Ge catalysts was prepared by surface redox reactions un... more A series of bimetallic Al2O3-supported Rh-Ge catalysts was prepared by surface redox reactions under controlled hydrogen atmosphere. The surface properties of these catalysts were probed via in-situ FTIR spectroscopic studies of adsorbed CO and were compared to those of monometallic Rh catalysts that had undergone similar treatments. The results indicate that Ge addition results in the formation and stabilization of smaller rhodium ensembles at the expense of larger Rh0 surfaces. A charge-transfer mechanism from Ge to Rh is also inferred by the IR results for the high Ge loading samples. Air exposure of the catalysts leads to an irreversible segregation of the two metals and formation of large Rh crystallites.
Journal of Catalysis, 2002
Catal Commun, 2002
The selective catalytic reduction of nitric oxide by propylene in the presence of excess oxygen h... more The selective catalytic reduction of nitric oxide by propylene in the presence of excess oxygen has been investigated over a series of silica supported Pt and PtAAu catalysts. Cluster-derived catalysts were prepared by wet impregnation using a Pt 2 Au 4 ðCBC t BuÞ 8 organometallic cluster precursor, and compared to catalysts obtained by incipient wetness impregnation using individual Pt and Au salts. The addition of Au by co-impregnation resulted only to a small shift (20-25°C) in the light-off of propylene towards higher temperatures. A markedly different catalytic behavior was observed in the case of cluster-derived catalysts, where a 150°C delay was observed both in the temperature of maximum NO reduction and the light-off of propylene in the presence and in the absence of NO. Most importantly, the selectivity towards N 2 increased by 50% compared to the monometallic Pt catalysts. The results of characterization studies indicate that the monometallic Pt=SiO 2 and the co-impregnated PtAAu=SiO 2 samples have similar metal particle sizes. A more narrow particle size distribution was observed with the cluster-derived bimetallic sample. Ó