Browsing by Subject "Catalysts"

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

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 ...

Article

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) ...

Article

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 ...

Article

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 ...

Article

The effects of Fe on the oxygen storage and release properties of model Pd-Rh/CeO2-Al2O3 three-way catalyst

Lambrou, Panayiota S.; Efstathiou, Angelos M. (2006)

This work attempts to gain fundamental information about the role of Fe in the chemical deactivation of a three-way catalyst (TWC), with Fe originating from materials used in the construction of automotive engines and ...

Article

The effects of the use of weak organic acids on the improvement of oxygen storage and release properties of aged commercial three-way catalysts

Lambrou, Panayiota S.; Christou, Stavroula Y.; Fotopoulos, Apostolos P.; Foti, F. K.; Angelidis, Thomas N.; Efstathiou, Angelos M. (2005)

The efficiency of weak organic acid solutions for improving the oxygen storage and release properties of aged commercial three-way catalysts (TWC) has been investigated. For the first time, three candidate leaching solutions, ...

Article

Group transfer polymerization in the bulk: Linear polymers and randomly cross-linked networks

Yamasaki, E. N.; Patrickios, Costas S. (2003)

Linear homopolymers and randomly cross-linked homopolymer networks of 2-(dimethylamino)ethyl methacrylate of various molecular weights (MWs) were synthesized by group transfer polymerization in the bulk. 1-methoxy-1-(tri ...

Article

Industrial H2-SCR of NO on a novel Pt/MgO-CeO2 catalyst

Costa, Costas N.; Savva, Petros G.; Fierro, José Luis García; Efstathiou, Angelos M. (2007)

We describe here the performance of a novel MgO-CeO2-supported Pt (0.1 wt%) catalyst towards the selective conversion of NO into N2 (SN2 > 80%) by using H2 (H2-SCR) under process conditions similar to those encountered in ...

Article

Influence of oxychlorination treatments on the redox and oxygen storage and release properties of thermally aged Pd-Rh/CexZr1-xO 2/Al2O3 model three-way catalysts

Daley, R. A.; Christou, Stavroula Y.; Efstathiou, Angelos M.; Anderson, J. A. (2005)

Model Pd-Rh/Al2O3 three-way catalysts with and without CexZr1-xO2 as oxygen storage component have been compared in their fresh, thermally aged and oxychlorinated treated surface states to determine the potential regenerating ...

Article

Kinetic and mechanistic studies of the water-gas shift reaction on Pt/TiO2 catalyst

Kalamaras, Christos M.; Panagiotopoulou, P.; Kondarides, D. I.; Efstathiou, Angelos M. (2009)

A detailed kinetic and mechanistic study of the water-gas shift (WGS) reaction on a 0.5 wt% Pt/TiO2 catalyst has been carried out. The dependence of kinetic reaction rate on the partial pressures of reactants (CO, H2O) and ...

Article

Low temperature and cost-effective growth of vertically aligned carbon nanofibers using spin-coated polymer-stabilized palladium nanocatalysts

Saleem, A. M.; Shafiee, S.; Krasia-Christoforou, T.; Savva, I.; Göransson, G.; Desmaris, V.; Enoksson, P. (2015)

We describe a fast and cost-effective process for the growth of carbon nanofibers (CNFs) at a temperature compatible with complementary metal oxide semiconductor technology, using highly stable polymer-Pd nanohybrid colloidal ...

Article

N2O decomposition over ceria-promoted Ir/Al2O3 catalysts: The role of ceria

Pachatouridou, E.; Papista, E.; Delimitis, Andréas; Vasiliades, Michalis A.; Efstathiou, Angelos M.; Amiridis, Michael D.; Alexeev, O. S.; Bloom, D.; Marnellos, G. E.; Konsolakis, M.; Iliopoulou, E. (2016)

The impact of CeO2 in the Al2O3-20wt% CeO2 support prepared by the co-precipitation method on the Ir particle size, morphology and oxidation state, and in turn on the deN2O catalytic activity (1000ppmN2O) of supported Ir ...

Article

Near-monodisperse α-hydroxy and α,ω-dihydroxy amine-based polymers: Synthesis and characterization

Costa, Costas N.; Patrickios, Costas S. (1999)

α-Hydroxy and α,ω-dihydroxy polymers of 2-(dimethylamino)ethyl methacrylate (DMAEMA) of various molecular weights were synthesized by group transfer polymerization (GTP) in tetrahydrofuran (THF), using 1-methoxy-1-(trime ...

Article

Origin and reactivity of active and inactive carbon formed during DRM over Ni/Ce0.38Zr0.62O2-δ studied by transient isotopic techniques

Vasiliades, Michalis A.; Djinović, P.; Davlyatova, L. F.; Pintar, A.; Efstathiou, Angelos M. (2016)

The role of Ce0.38Zr0.62O2-δ redox support and that of reactants CH4 and CO2 in the carbon-path of dry reforming of methane (DRM) at 750°C over a 3wt% Ni/Ce0.38Zr0.62O2-δ catalyst were investigated. In particular, meticulously ...

Article

The phenol steam reforming reaction over MgO-based supported Rh catalysts

Polychronopoulou, Kyriaki; Fierro, José Luis García; Efstathiou, Angelos M. (2004)

The phenol steam reforming reaction toward H2 formation has been investigated in the 575-730°C range over MgO, CeO2, and ZrO 2 single metal oxides and various mixed metal oxides such as Mg-Ce-O, Mg-Zr-O, and Mg-Ce-Zr-O, ...

Article

Reactivation of severely aged commercial three-way catalysts by washing with weak EDTA and oxalic acid solutions

Christou, Stavroula Y.; Birgersson, H.; Efstathiou, Angelos M. (2007)

Ethylene diamine tetraacetic acid (EDTA) which is a well-known reagent for its metal extraction efficiency was studied for the first time towards the improvement of the catalytic activity and oxygen storage and release ...

Article

Reforming of methane with carbon dioxide to synthesis gas over supported Rh catalysts

Tsipouriari, Vaso A.; Efstathiou, Angelos M.; Zhang, Z. L.; Verykios, Xenophon E. (1994)

Reforming of methane with carbon dioxide to synthesis gas (CO/H2) has been investigated over rhodium supported on SiO2, TiO2, γ-Al2O3, MgO, CeO2, and YSZ (ZrO2 (8 mol% Y2O3)) catalysts in the temperature range of 650-750°C ...

Article

Regeneration of thermally aged Pt-Rh/CexZr1-xO2-Al2O3 model three-way catalysts by oxychlorination treatments

Anderson, J. A.; Daley, R. A.; Christou, Stavroula Y.; Efstathiou, Angelos M. (2006)

Pt-Rh/CexZr1-xO2-Al2O3 with 0.6 and 1.0 wt.% noble metal loadings were prepared and characterized for their metal dispersion with respect to CexZr1-xO2-free Pt-Rh/Al2O3 in fresh, thermally aged and oxychlorinated states. ...

Article

Regiospecific Suzuki coupling of 3,5-dichloroisothiazole-4-carbonitrile

Christoforou, Irene C.; Koutentis, Panayiotis Andreas; Rees, C. W. (2003)

3,5-Dichloroisothiazole-4-carbonitrile 1 reacts with aryl- and methylboronic acids to give in high yields the 3-chloro-5-(aryl and methyl)-isothiazole-4-carbonitrile 2 regiospecifically. The reaction was optimized with ...