Browsing by Author "Efstathiou, Angelos M."

Article

Absorption-enhanced reforming of phenol by steam over supported Fe catalysts

Polychronopoulou, Kyriaki; Bakandritsos, Aristides; Tzitzios, Vasileios; Fierro, José Luis García; Efstathiou, Angelos M. (2006)

Supported Fe catalysts of varying support chemical composition prepared by sol-gel and incipient wetness impregnation methods were studied for the steam reforming of phenol (one of the main constituents of tar produced ...

Article

Adsorption study by transient tracing methods. theory and modeling

Szedlacsek, P.; Efstathiou, Angelos M.; Bennett, C. O.; Suib, S. L. (1993)

The advantages of transient tracing methods (TTM) in studying heterogeneous catalytic systems have been described by many authors. This chapter presents a new application of TTM for studying adsorption. The basic idea of ...

Article

Ball Milling Effect on the CO2 Uptake of Mafic and Ultramafic Rocks: A Review

Rigopoulos, Ioannis; Ioannou, Ioannis; Delimitis, Andreas; Efstathiou, Angelos M.; Kyratsi, Theodora (2018)

Mineral carbonation is considered to be the most stable mechanism for the sequestration of CO2. This study comprises a comparative review of the effect of ball milling on the CO2 uptake of ultramafic/mafic lithologies, ...

Article

Ball Milling Effect on the CO2 Uptake of Mafic and Ultramafic Rocks: A Review

Rigopoulos, Ioannis; Ioannou, Ioannis; Delimitis, Andreas; Efstathiou, Angelos M.; Kyratsi, Theodora (2018)

Mineral carbonation is considered to be the most stable mechanism for the sequestration of CO2. This study comprises a comparative review of the effect of ball milling on the CO2 uptake of ultramafic/mafic lithologies, ...

Article

The C2H4/He reaction on Rh/MgO studied by transient methods

Efstathiou, Angelos M. (1991)

The reaction of a 0.5 mol% C2H4/He mixture with 2.5 wt% Rh/MgO at 310 and 533 K was studied by employing transient and temperature-programmed methods. The reaction of C2H4/He at 310 K gives CH4 and C2H6 in the gas phase, ...

Article

Carbon dioxide storage in olivine basalts: Effect of ball milling process

Rigopoulos, Ioannis; Petallidou, Klito C.; Vasiliades, Michalis A.; Delimitis, Andréas; Ioannou, Ioannis; Efstathiou, Angelos M.; Kyratsi, Theodora (2015)

The goal of this study is to propose a cost-effective method for the optimization of the ex situ carbonation of basaltic rocks. The ball milling process was applied to a sample of olivine basalt from the Troodos ophiolite ...

Article

Carbon sequestration via enhanced weathering of peridotites and basalts in seawater

Rigopoulos, Ioannis; Harrison, Anna L.; Delimitis, Andreas; Ioannou, Ioannis; Efstathiou, Angelos M.; Kyratsi, Theodora; Oelkers, Eric H. (2018)

Enhanced weathering of mafic and ultramafic rocks has been suggested as a carbon sequestration strategy for the mitigation of climate change. This study was designed to assess the potential drawdown of CO2 directly from ...

Article

Carbon sequestration via enhanced weathering of peridotites and basalts in seawater

Rigopoulos, Ioannis; Harrison, Anna L.; Delimitis, Andreas; Ioannou, Ioannis; Efstathiou, Angelos M.; Kyratsi, Theodora; Oelkers, Eric H. (2018)

Enhanced weathering of mafic and ultramafic rocks has been suggested as a carbon sequestration strategy for the mitigation of climate change. This study was designed to assess the potential drawdown of CO2 directly from ...

Book

Catalysis 28

Tshentu, Zenixole R.; Dai, Wei-Lin; Jin, Rongchao; Efstathiou, Angelos M.; Coppens, Marc-Oliver; Murzin, Dmitry; Spivey, James; Dooley, K. M.; Han, Yi-Fan [Main author]

Article

Catalytic activity of high surface area mesoporous mn-based mixed oxides for the deep oxidation of methane and lean-nox reduction

Stathopoulos, Vassilis N.; Belessi, Vassiliki C.; Costa, Costas N.; Neophytides, Stylianos G.; Falaras, Polycarpos; Efstathiou, Angelos M.; Pomonis, Phillippos J. (2000)

Article

Catalytic behavior of La-Sr-Ce-Fe-O mixed oxidic/perovskitic systems for the NO+CO and NO+CH4+O2 (lean-NOx) reactions

Belessi, Vassiliki C.; Costa, Costas N.; Bakas, Thomas V.; Anastasiadou, T.; Pomonis, Phillippos J.; Efstathiou, Angelos M. (2000)

Mixed oxides of the general formula La0.5SrxCeyFeOz were prepared by using the nitrate method and characterized by XRD and Mossbauer techniques. The crystal phases detected were perovskites LaFeO3 and SrFeO3-x and oxides ...

Article

Catalytic removal of nitrates from waters

Constantinou, C. L.; Costa, Costas N.; Efstathiou, Angelos M. (2010)

The selective catalytic reduction of nitrates (NO3 -) in pure water towards N2 formation by the use of gaseous H2 and in the presence of O2 (air) at 1 atm total pressure and 25 °C has been investigated over Pd-Cu supported ...

Article

Ceria-based materials for hydrogen production via hydrocarbon steam reforming and water-gas shift reactions

Polychronopoulou, Kyriaki; Kalamaras, Christos M.; Efstathiou, Angelos M. (2011)

This review paper provides an overview of the use of ceria-based catalytic materials towards the industrial hydrogen production via the hydrocarbon steam reforming and the water-gas shift reaction routes with a focus on ...

Article

The CH4/NO/O2 "lean-deNOx" reaction on mesoporous Mn-based mixed oxides

Stathopoulos, Vassilis N.; Costa, Costas N.; Pomonis, Phillippos J.; Efstathiou, Angelos M. (2001)

High surface area Mn-based porous oxides (MANPO) containing additives like Ce, Sr and La were found to be very active and selective materials under 0.67% CH4/0.2% NO/5% O2 "lean-deNOx" conditions in the 200-300°C low-temperature ...

Article

Characterization of carbonaceous species formed during reforming of CH4 with CO2 over Ni/CaO-Al2O3 catalysts studied by various transient techniques

Goula, M. A.; Lemonidou, A. A.; Efstathiou, Angelos M. (1996)

Carbon dioxide reforming of methane to synthesis gas at 750°C over 5 wt% Ni/CaO-Al2O3 catalysts has been investigated with respect to effects of support composition (CaO to Al2O3 ratio) on catalyst stability, amount and ...

Article

CO adsorption on transition metal clusters: Trends from density functional theory

Zeinalipour-Yazdi, Constantinos D.; Cooksy, A. L.; Efstathiou, Angelos M. (2008)

This work reports for the first time the trends for carbon monoxide (CO) chemisorption on transition metal clusters present in supported metal catalysts. In particular, the energetic, structural and infrared adsorption ...

Article

CO chemisorption and hydrogenation of surface carbon species formed after CO/He reaction on Rh/MgO: A transient kinetic study using FTIR and mass spectroscopy

Efstathiou, Angelos M.; Chafik, T.; Bianchi, D.; Bennett, C. O. (1994)

The chemisorption of CO and hydrogenation of surface adsorbed carbon species formed after reaction of CO/He with Rh/MgO catalyst in the range 300-573 K were studied by transient methods employing both FTIR and mass ...

Article

The CO H2 reaction on Rh Al2O3. I. Steady-state and transient kinetics

Efstathiou, Angelos M.; Bennett, C. O. (1989)

Various hydrogen titrations yield the surface composition of Rh Al2O3 during the CO H2 reaction at temperatures in the range 180-260 °C. There is a very small amount of active carbon Ca, 0.02-0.06 monolayer, and 0.70-0.98 ...

Article

The CO H2 reaction on Rh Al2O3. II. Kinetic study by transient isotopic methods

Efstathiou, Angelos M.; Bennett, C. O. (1989)

Transient isotopic methods have been used to study the CO H2 reaction over 5% Rh Al2O3 in the temperature range 180-260 °C. The steady-state tracing method permits the determination of the surface coverage of CO and active ...

Article

CO oxidation over Rh dispersed on SiO2, Al2O3 and TiO2: Kinetic study and oscillatory behavior

Ioannides, T.; Efstathiou, Angelos M.; Zhang, Z. L.; Verykios, Xenophon E. (1995)

The kinetic behavior of Rh supported on SiO2, Al2O3, and TiO2 in the CO oxidation reaction has been investigated. It was found that the maximum turnover frequency (TOF) is approximately the same over the three catalysts, ...