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Israel E. Wachs - One of the best experts on this subject based on the ideXlab platform.
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Molecular/electronic Structure–Surface acidity relationships of model-supported tungsten oxide catalysts
Journal of Catalysis, 2007Co-Authors: Taejin Kim, Andrew Burrows, Christopher J. Kiely, Israel E. WachsAbstract:A series of model-supported WO3 catalysts were synthesized on preformed Al2O3, Nb2O5, TiO2, and ZrO2 supports by impregnation of aqueous ammonium metatungstate, (NH4)10W12O41⋅5H2O. The molecular and electronic Structures of the supported tungsten oxide phases were determined with in situ Raman and UV–vis spectroscopy, respectively. The supported tungsten oxide Structures are the same on all oxide supports as a function of tungsten oxide Surface density (W/nm2). Below monolayer coverage ( 5 W/nm2), crystalline WO3 nanoparticles are present on top of the Surface WOx monolayer. Above ∼10 W/nm2, bulk-like WO3 crystallites become dominant. The number of catalytic active sites and Surface chemistry of the supported tungsten oxide phases were chemically probed with CH3OH dehydration to CH3OCH3. The specific oxide support was found to significantly affect the relative catalytic acidity of the Surface WOx species (Al2O3 ≫ TiO2 > Nb2O5 > ZrO2) to that of the supported WO3 nanoparticles. Consequently, no general relationship exists between the molecular/electronic Structures or domain size and the specific catalytic acidity of the supported tungsten oxide phases present in the model-supported WO3 catalysts.
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molecular electronic Structure Surface acidity relationships of model supported tungsten oxide catalysts
Journal of Catalysis, 2007Co-Authors: Taejin Kim, Andrew Burrows, Christopher J. Kiely, Israel E. WachsAbstract:A series of model-supported WO3 catalysts were synthesized on preformed Al2O3, Nb2O5, TiO2, and ZrO2 supports by impregnation of aqueous ammonium metatungstate, (NH4)10W12O41⋅5H2O. The molecular and electronic Structures of the supported tungsten oxide phases were determined with in situ Raman and UV–vis spectroscopy, respectively. The supported tungsten oxide Structures are the same on all oxide supports as a function of tungsten oxide Surface density (W/nm2). Below monolayer coverage ( 5 W/nm2), crystalline WO3 nanoparticles are present on top of the Surface WOx monolayer. Above ∼10 W/nm2, bulk-like WO3 crystallites become dominant. The number of catalytic active sites and Surface chemistry of the supported tungsten oxide phases were chemically probed with CH3OH dehydration to CH3OCH3. The specific oxide support was found to significantly affect the relative catalytic acidity of the Surface WOx species (Al2O3 ≫ TiO2 > Nb2O5 > ZrO2) to that of the supported WO3 nanoparticles. Consequently, no general relationship exists between the molecular/electronic Structures or domain size and the specific catalytic acidity of the supported tungsten oxide phases present in the model-supported WO3 catalysts.
Taejin Kim - One of the best experts on this subject based on the ideXlab platform.
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Molecular/electronic Structure–Surface acidity relationships of model-supported tungsten oxide catalysts
Journal of Catalysis, 2007Co-Authors: Taejin Kim, Andrew Burrows, Christopher J. Kiely, Israel E. WachsAbstract:A series of model-supported WO3 catalysts were synthesized on preformed Al2O3, Nb2O5, TiO2, and ZrO2 supports by impregnation of aqueous ammonium metatungstate, (NH4)10W12O41⋅5H2O. The molecular and electronic Structures of the supported tungsten oxide phases were determined with in situ Raman and UV–vis spectroscopy, respectively. The supported tungsten oxide Structures are the same on all oxide supports as a function of tungsten oxide Surface density (W/nm2). Below monolayer coverage ( 5 W/nm2), crystalline WO3 nanoparticles are present on top of the Surface WOx monolayer. Above ∼10 W/nm2, bulk-like WO3 crystallites become dominant. The number of catalytic active sites and Surface chemistry of the supported tungsten oxide phases were chemically probed with CH3OH dehydration to CH3OCH3. The specific oxide support was found to significantly affect the relative catalytic acidity of the Surface WOx species (Al2O3 ≫ TiO2 > Nb2O5 > ZrO2) to that of the supported WO3 nanoparticles. Consequently, no general relationship exists between the molecular/electronic Structures or domain size and the specific catalytic acidity of the supported tungsten oxide phases present in the model-supported WO3 catalysts.
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molecular electronic Structure Surface acidity relationships of model supported tungsten oxide catalysts
Journal of Catalysis, 2007Co-Authors: Taejin Kim, Andrew Burrows, Christopher J. Kiely, Israel E. WachsAbstract:A series of model-supported WO3 catalysts were synthesized on preformed Al2O3, Nb2O5, TiO2, and ZrO2 supports by impregnation of aqueous ammonium metatungstate, (NH4)10W12O41⋅5H2O. The molecular and electronic Structures of the supported tungsten oxide phases were determined with in situ Raman and UV–vis spectroscopy, respectively. The supported tungsten oxide Structures are the same on all oxide supports as a function of tungsten oxide Surface density (W/nm2). Below monolayer coverage ( 5 W/nm2), crystalline WO3 nanoparticles are present on top of the Surface WOx monolayer. Above ∼10 W/nm2, bulk-like WO3 crystallites become dominant. The number of catalytic active sites and Surface chemistry of the supported tungsten oxide phases were chemically probed with CH3OH dehydration to CH3OCH3. The specific oxide support was found to significantly affect the relative catalytic acidity of the Surface WOx species (Al2O3 ≫ TiO2 > Nb2O5 > ZrO2) to that of the supported WO3 nanoparticles. Consequently, no general relationship exists between the molecular/electronic Structures or domain size and the specific catalytic acidity of the supported tungsten oxide phases present in the model-supported WO3 catalysts.
Andrew Burrows - One of the best experts on this subject based on the ideXlab platform.
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Molecular/electronic Structure–Surface acidity relationships of model-supported tungsten oxide catalysts
Journal of Catalysis, 2007Co-Authors: Taejin Kim, Andrew Burrows, Christopher J. Kiely, Israel E. WachsAbstract:A series of model-supported WO3 catalysts were synthesized on preformed Al2O3, Nb2O5, TiO2, and ZrO2 supports by impregnation of aqueous ammonium metatungstate, (NH4)10W12O41⋅5H2O. The molecular and electronic Structures of the supported tungsten oxide phases were determined with in situ Raman and UV–vis spectroscopy, respectively. The supported tungsten oxide Structures are the same on all oxide supports as a function of tungsten oxide Surface density (W/nm2). Below monolayer coverage ( 5 W/nm2), crystalline WO3 nanoparticles are present on top of the Surface WOx monolayer. Above ∼10 W/nm2, bulk-like WO3 crystallites become dominant. The number of catalytic active sites and Surface chemistry of the supported tungsten oxide phases were chemically probed with CH3OH dehydration to CH3OCH3. The specific oxide support was found to significantly affect the relative catalytic acidity of the Surface WOx species (Al2O3 ≫ TiO2 > Nb2O5 > ZrO2) to that of the supported WO3 nanoparticles. Consequently, no general relationship exists between the molecular/electronic Structures or domain size and the specific catalytic acidity of the supported tungsten oxide phases present in the model-supported WO3 catalysts.
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molecular electronic Structure Surface acidity relationships of model supported tungsten oxide catalysts
Journal of Catalysis, 2007Co-Authors: Taejin Kim, Andrew Burrows, Christopher J. Kiely, Israel E. WachsAbstract:A series of model-supported WO3 catalysts were synthesized on preformed Al2O3, Nb2O5, TiO2, and ZrO2 supports by impregnation of aqueous ammonium metatungstate, (NH4)10W12O41⋅5H2O. The molecular and electronic Structures of the supported tungsten oxide phases were determined with in situ Raman and UV–vis spectroscopy, respectively. The supported tungsten oxide Structures are the same on all oxide supports as a function of tungsten oxide Surface density (W/nm2). Below monolayer coverage ( 5 W/nm2), crystalline WO3 nanoparticles are present on top of the Surface WOx monolayer. Above ∼10 W/nm2, bulk-like WO3 crystallites become dominant. The number of catalytic active sites and Surface chemistry of the supported tungsten oxide phases were chemically probed with CH3OH dehydration to CH3OCH3. The specific oxide support was found to significantly affect the relative catalytic acidity of the Surface WOx species (Al2O3 ≫ TiO2 > Nb2O5 > ZrO2) to that of the supported WO3 nanoparticles. Consequently, no general relationship exists between the molecular/electronic Structures or domain size and the specific catalytic acidity of the supported tungsten oxide phases present in the model-supported WO3 catalysts.
Christopher J. Kiely - One of the best experts on this subject based on the ideXlab platform.
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Molecular/electronic Structure–Surface acidity relationships of model-supported tungsten oxide catalysts
Journal of Catalysis, 2007Co-Authors: Taejin Kim, Andrew Burrows, Christopher J. Kiely, Israel E. WachsAbstract:A series of model-supported WO3 catalysts were synthesized on preformed Al2O3, Nb2O5, TiO2, and ZrO2 supports by impregnation of aqueous ammonium metatungstate, (NH4)10W12O41⋅5H2O. The molecular and electronic Structures of the supported tungsten oxide phases were determined with in situ Raman and UV–vis spectroscopy, respectively. The supported tungsten oxide Structures are the same on all oxide supports as a function of tungsten oxide Surface density (W/nm2). Below monolayer coverage ( 5 W/nm2), crystalline WO3 nanoparticles are present on top of the Surface WOx monolayer. Above ∼10 W/nm2, bulk-like WO3 crystallites become dominant. The number of catalytic active sites and Surface chemistry of the supported tungsten oxide phases were chemically probed with CH3OH dehydration to CH3OCH3. The specific oxide support was found to significantly affect the relative catalytic acidity of the Surface WOx species (Al2O3 ≫ TiO2 > Nb2O5 > ZrO2) to that of the supported WO3 nanoparticles. Consequently, no general relationship exists between the molecular/electronic Structures or domain size and the specific catalytic acidity of the supported tungsten oxide phases present in the model-supported WO3 catalysts.
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molecular electronic Structure Surface acidity relationships of model supported tungsten oxide catalysts
Journal of Catalysis, 2007Co-Authors: Taejin Kim, Andrew Burrows, Christopher J. Kiely, Israel E. WachsAbstract:A series of model-supported WO3 catalysts were synthesized on preformed Al2O3, Nb2O5, TiO2, and ZrO2 supports by impregnation of aqueous ammonium metatungstate, (NH4)10W12O41⋅5H2O. The molecular and electronic Structures of the supported tungsten oxide phases were determined with in situ Raman and UV–vis spectroscopy, respectively. The supported tungsten oxide Structures are the same on all oxide supports as a function of tungsten oxide Surface density (W/nm2). Below monolayer coverage ( 5 W/nm2), crystalline WO3 nanoparticles are present on top of the Surface WOx monolayer. Above ∼10 W/nm2, bulk-like WO3 crystallites become dominant. The number of catalytic active sites and Surface chemistry of the supported tungsten oxide phases were chemically probed with CH3OH dehydration to CH3OCH3. The specific oxide support was found to significantly affect the relative catalytic acidity of the Surface WOx species (Al2O3 ≫ TiO2 > Nb2O5 > ZrO2) to that of the supported WO3 nanoparticles. Consequently, no general relationship exists between the molecular/electronic Structures or domain size and the specific catalytic acidity of the supported tungsten oxide phases present in the model-supported WO3 catalysts.
Yaoqiang Chen - One of the best experts on this subject based on the ideXlab platform.
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Structure, Surface and reactivity of activated carbon: From model soot to Bio Diesel soot
Fuel, 2019Co-Authors: Hailong Zhang, Yi Jiao, Eduard Emil Iojoiu, Patrick Da Costa, Maria Elena Galvez, Yaoqiang ChenAbstract:Abstract The present work aims to investigate and compare the Structure, Surface and reactivity of the activated Printex U carbon black and real Bio soot samples through BET, Raman, HRTEM, XPS, DRIFTS and temperature-programmed oxidation (TPO). TPO evidenced that the activated Printex U carbon black was more reactive than the activated Biodiesel soot (B7 and B100) generated from a real engine under both O2 and NO + O2. BET displayed an increased Surface area and a decreased pore size for the activated soot. Raman and HRTEM revealed that the activated soot showed decreased structural order. The morphology features also confirmed different combustion pathway for Printex U and B100. XPS illustrated that the activation decreased Surface graphene carbon and increased Surface oxygen content. DRIFTS indicated that real Bio soot had higher concentration of Surface functional groups than Printex U model soot, and a more apparent increase in Surface functional groups was observed for the activated Printex U soot. It was proved that the reactivity of the activated Printex U is more dependent on structural and Surface properties compared with that of the activated Biodiesel soot samples.
