Browsing by Author "Efstathiou, Angelos M."
Now showing items 21-40 of 153
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CO-Induced changes in the oxidation state of rhodium supported on MgO: X-Ray photoelectron spectroscopic study
Efstathiou, Angelos M.; Tan, B. J.; Suib, S. L. (1993)The oxidation state of Rh after various CO/He treatments with a 2.5 wt% Rh/MgO catalyst was investigated with X-ray photoelectron spectroscopy. The rhodium metal particles, initially in a reduced state (Rh0), were found ...
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The CO/H2 reaction on Rh/MgO studied by transient isotopic methods
Efstathiou, Angelos M. (1991)Various transient isotopic methods have been used to study the CO/H2 reaction over 2.5 wt% Rh/MgO catalyst at temperatures in the range 493-573 K. The steady-state tracing method permits the determination of the surface ...
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Comparative study of La-Sr-Fe-O perovskite-type oxides prepared by ceramic and surfactant methods over the CH4 and H2 lean-deNOx
Stathopoulos, Vassilis N.; Belessi, Vassiliki C.; Bakas, Thomas V.; Neophytides, Stylianos G.; Costa, Costas N.; Pomonis, Phillippos J.; Efstathiou, Angelos M. (2009)Mixed oxides of the general formula La0.8Sr0.2FeO3-x were prepared by ceramic and surfactant methods and tested towards the NO/H2/O2 and NO/CH4/O2 lean-deNOx reactions in the 200-450 °C range. The materials were characterized ...
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A comparative study of the steam reforming of phenol towards H2 production over natural calcite, dolomite and olivine materials
Constantinou, D. A.; Fierro, José Luis García; Efstathiou, Angelos M. (2010)Pre-calcined (air, 850 °C) naturally occurring calcite, dolomite and olivine materials were studied for phenol steam reforming towards H2 production. The effect of reaction temperature, feed volume flow rate, and hydrogen ...
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Cu-Ce-La-Ox as efficient CO oxidation catalysts: Effect of Cu content
AlKetbi, Maitha; Polychronopoulou, Kyriaki; Abi Jaoude, Maguy; Vasiliades, Michalis A.; Sebastian, Victor; Hinder, Steven J.; Baker, Mark A.; Zedan, Abdallah F.; Efstathiou, Angelos M. (2020)Nanograins of Ce-La-xCu-O mixed metal oxides (wherex = 3, 5, 7, 10, 20 at.%), of approximately 16 nm2 area size, and having all the metal cations homogeneously distributed, are tested as ternary catalytic materials towards ...
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Cyclopropane isomerization over Eu3+NaX zeolites
Simon, M. W.; Efstathiou, Angelos M.; Bennett, C. O.; Suib, S. L. (1992)Cyclopropane isomerization to propylene over various Eu3+ loadings in NaX zeolite have been studied by measurements of steady-state and transient kinetics and by Fourier transform infrared spectroscopy. As Eu3+ loading ...
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Deactivation of Pd/Ce 0.5Zr 0.5O 2 model three-way catalyst by P, Ca and Zn deposition
Christou, Stavroula Y.; García-Rodríguez, S.; Fierro, José Luis García; Efstathiou, Angelos M. (2012)The negative effects of P, P-Ca and P-Zn deposition on the surface of a model 1wt% Pd/Ce 0.5Zr 0.5O 2 " three-way" catalyst (TWC) on its structural, morphological, textural, oxygen storage and release, and catalytic ...
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A diffuse reflectance infrared fourier-transform spectra and density functional theory study of CO adsorption on Rhγ-Al2O 3
Zeinalipour-Yazdi, Constantinos D.; Cooksy, A. L.; Efstathiou, Angelos M. (2007)The vibrational frequencies and bond dissociation energies of carbon monoxide adsorbed to various rhodium clusters are computed, and the diffuse reflectance infrared Fourier-transform (DRIFT) spectrum of carbon monoxide ...
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Dry reforming of methane over 5 wt% Ni/Ce1-xPrxO2-δ catalysts: Performance and characterisation of active and inactive carbon by transient isotopic techniques
Vasiliades, Michalis A.; Makri, M. M.; Djinović, P.; Erjavec, B.; Pintar, A.; Efstathiou, Angelos M. (2016)The effects of Ce1-xPrxO2-δ support composition (x = 0.0–0.8) and reaction temperature (550–750 °C) on the catalytic activity and selectivity and important features of the mechanism of the dry reforming of methane (DRM) ...
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Dynamics of oxygen storage and release on commercial aged Pd-Rh three-way catalysts and their characterization by transient experiments
Lambrou, Panayiota S.; Costa, Costas N.; Christou, Stavroula Y.; Efstathiou, Angelos M. (2004)The present work has provided new fundamental information on the effects of aging (mileage, km) of a commercial Pd-Rh (9:1, w/w) three-way catalyst (TWC) on (a) the H 2 chemisorption, (b) the redox properties of washcoat ...
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Effect of ball milling on the carbon sequestration efficiency of serpentinized peridotites
Rigopoulos, Ioannis; Delimitis, Andreas; Ioannou, Ioannis; Efstathiou, Angelos M.; Kyratsi, Theodora (2018)Mineral carbonation has been suggested as a safe carbon capture and storage (CCS) strategy for the mitigation of climate change. This study investigates the effect of ball milling on the CO2 sequestration capacity of ...
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Effect of ball milling on the carbon sequestration efficiency of serpentinized peridotites
Rigopoulos, Ioannis; Delimitis, Andreas; Ioannou, Ioannis; Efstathiou, Angelos M.; Kyratsi, Theodora (2018)Mineral carbonation has been suggested as a safe carbon capture and storage (CCS) strategy for the mitigation of climate change. This study investigates the effect of ball milling on the CO2 sequestration capacity of ...
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The effect of calcination temperature on the oxygen storage and release properties of CeO2 and Ce-Zr-O metal oxides modified by phosphorus incorporation
Larese, C.; López Granados, M.; Mariscal, R.; Fierro, José Luis García; Lambrou, Panayiota S.; Efstathiou, Angelos M. (2005)The present work reports on the effects of calcination temperature (T c) on the oxygen storage and release properties of CeO2 and Ce0.8Zr0.2O2 solids deliberately contaminated with CePO4. Pulsed-feed and stepped-feed dynamic ...
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The Effect of CeO2 Preparation Method on the Carbon Pathways in the Dry Reforming of Methane on Ni/CeO2 Studied by Transient Techniques
Damaskinos, Constantinos M.; Vasiliades, Michalis A.; Stathopoulos, Vassilis N.; Efstathiou, Angelos M. (2019)The present work discusses the effect of CeO2 synthesis method (thermal decomposition (TD), precipitation (PT), hydrothermal (HT), and sol-gel (SG)) on the carbon pathways of dry reforming of methane with carbon dioxide ...
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The effect of Fe on the catalytic behavior of model Pd-Rh/CeO2-Al2O3 three-way catalyst
Lambrou, Panayiota S.; Savva, Petros G.; Fierro, José Luis García; Efstathiou, Angelos M. (2007)The present work attempts to address the issue whether iron (Fe) which is accumulated on the surface of "three-way" catalysts (TWCs) used in gasoline-driven cars is a true chemical poison of their catalytic activity. This ...
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The effect of La3+, Ti4+ and Zr4+ dopants on the mechanism of WGS on ceria-doped supported Pt catalysts
Petallidou, Klito C.; Kalamaras, Christos M.; Efstathiou, Angelos M. (2014)Platinum nanoparticles supported on single CeO2 and TiO 2 metal oxides and Ce0.8Ti0.2O 2-δ solid solution were prepared to investigate the effect of Ti4+-doping of ceria on important mechanistic and kinetic aspects of the ...
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The effect of La3+-doping of CeO2 support on the water-gas shift reaction mechanism and kinetics over Pt/Ce1-xLaxO2-δ
Kalamaras, Christos M.; Petallidou, Klito C.; Efstathiou, Angelos M. (2013)Platinum nanoparticles (dPt=1.0-1.2nm) supported on single CeO2 and La2O3 metal oxides and Ce0.8La0.2O2-δ solid solution were prepared to investigate for the first time the effect of La3+-doping of ceria on important ...
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The effect of preparation route of commercial Co/γ-Al2O3 catalyst on important Fischer-Tropsch kinetic parameters studied by SSITKA and CO-DRIFTS transient hydrogenation techniques
Vasiliades, M. A.; Kalamaras, C. M.; Govender, N. S.; Govender, A.; Efstathiou, Angelos M. (2019)Two commercial Co-based catalysts supported on carbon-coated and uncoated γ-Al2O3 (during Co deposition) of different Co particle size (∼7 and 10 nm) and surface structure were investigated to address the effect of preparation ...
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The effect of Pt on the carbon pathways in the dry reforming of methane over Ni-Pt/Ce0.8Pr0.2O2-δ catalyst
Vasiliades, M. A.; Damaskinos, C. M.; Kyprianou, K. K.; Kollia, M.; Efstathiou, Angelos M. (2019)The present work extensively discusses the carbon pathways in the dry reforming of methane with carbon dioxide (DRM) at 750 °C towards syngas (CO/H2 ˜ 1) over 5 wt% Ni, 0.5 wt% Pt and their bimetallic alloy (5 wt% Ni-0.5 wt% ...
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Effect of support composition on the origin and reactivity of carbon formed during dry reforming of methane over 5 wt% Ni/Ce1-xMxO2-δ (M = Zr4+, Pr3+) catalysts
Makri, M. M.; Vasiliades, Michalis A.; Petallidou, Klito C.; Efstathiou, Angelos M. (2016)Carbon dioxide reforming of methane to synthesis gas in the 550-750°C range over 5 wt% Ni/Ce1-xMxO2-δ (M = Zr4+, Pr3+) solids has been investigated with respect to the effects of support chemical composition and reaction ...