Induced changes in ceria by thermal treatments under vacuum or hydrogen

Fierro, J.L.G.; Soria, J.; Sanz, J.; Rojo, J. M.

doi:10.1016/0022-4596(87)90230-1

Cited by 243 publications

(139 citation statements)

References 9 publications

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“…Within such a low temperature interval, the mobility of oxygen from the deeper layers is not very likely. It has to be taken also into account that a small amount of hydrogen could be retained into the bulk of ceria as well [34,35].…”

Section: Discussionmentioning

confidence: 99%

NO reduction by CO over gold catalysts based on ceria supports, prepared by mechanochemical activation, modified by Me3+ (Me = Al or lanthanides): Effect of water in the feed gas

Ilieva

Pantaleo

Nedyalkova

et al. 2009

Applied Catalysis B: Environmental

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Section: Discussionmentioning

confidence: 99%

NO reduction by CO over gold catalysts based on ceria supports, prepared by mechanochemical activation, modified by Me3+ (Me = Al or lanthanides): Effect of water in the feed gas

Ilieva

Pantaleo

Nedyalkova

et al. 2009

Applied Catalysis B: Environmental

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“…Again, the pretreatments had to be ; however, according to the literature, such paramagnetic ion could be observed at very low temperature only (T <20 K) [41,42]. Some authors proposed that this signal originated from Ce 3+ in peculiar geometry/ symmetry [43,44], while other authors proposed that it arises from quasi-free electrons with some orbital mixing with the empty f-orbitals of Ce 4+ ions [23,45]. Upon addition of O 2 , the signal at g≈ 1.97 remained unchanged, which further strengthened the hypothesis of a paramagnetic species trapped in the bulk of the CeO 2 particles (no possible dipolar interaction with O 2 that could affect the signal).…”

Section: Identification Of Oxygen Active Speciesmentioning

confidence: 99%

Understanding of the oxygen activation on ceria- and ceria/alumina-supported gold catalysts: a study combining 18O/16O isotopic exchange and EPR spectroscopy

et al. 2013

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Gold supported on ceria or ceria-alumina mixed oxides are very active catalysts for total oxidation of a variety of molecules. The key step of the oxygen activation on such catalysts is still a matter of debate. Gold-ceria (Au/CeO 2 ) and gold-ceria-alumina (Au/CeO 2 /Al 2 O 3 ) catalysts were prepared by deposition-precipitation of gold precursor with urea as in former works where their efficiency to catalyze the oxidation of propene and propan-2-ol was demonstrated. To understand the phenomenon of oxygen activation over this class of catalysts, efficient techniques generally used to characterize the interaction between oxygen and cerium-based oxides were applied; the oxygen storage capacity (OSC) measurement, the O (g) ), indicating that gold did not promote the dissociation of dioxygen. Peroxo adspecies were observed by Raman spectroscopy only in the presence of gold. On the contrary, EPR spectroscopy indicated that the concentration of superoxo adspecies was lower for oxide-supported gold samples than for bare oxides. The combination of techniques allowed reinforcing the hypothesis that the gold nanoparticules promote the activation of dioxygen by generating extremely mobile diatomicoxygenated species at the gold/ceria interfacial perimeter. This specific gold-ceria interaction, which leads to the increase in oxygen mobility, is probably also responsible for the higher catalytic performance of Au/CeO 2 and Au/CeO 2 /Al 2 O 3 in oxidation reaction compared to bare supports.

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“…CeO2 retains its defective fluorite-type crystal structure during the oxygen storage and release processes, and thus is an active oxide component of various oxidation catalysts used in diverse redox catalytic reactions [4,5]. Ceria-based catalysts are very good WGS catalysts [6][7][8][9], and the Cu-CeO2 system was first reported by Li et al as a promising lowtemperature shift catalyst [6].…”

Section: Introductionmentioning

confidence: 99%

Water gas shift reaction over Cu catalyst supported by mixed oxide materials for fuel cell application

Tepamatr

Charojrochkul

Laosiripojana

2016

MATEC Web of Conferences

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Abstract. The water gas shift activities of Cu on ceria and Gd doped ceria have been studied for the further enhancement of hydrogen purity [1] after the steam reforming of ethanol. The catalytic properties of commercial catalysts were also studied to compare with the as-prepared catalysts. Copper-containing cerium oxide materials are shown in this work to be suitable for the high temperature. Copper-ceria is a stable high-temperature shift catalyst, unlike iron-chrome catalysts that deactivate severely in CO2-rich gases. We found that 5%Cu/10%GDC(D) has much higher activity than other copper ceria based catalysts. The finely dispersed CuO species is favorable to the higher activity, which explained the activity enhancement of this catalyst. The kinetics of the WGS reaction over Cu catalysts supported by mixed oxide materials were measured in the temperature range 200-400 °C. An independence of the CO conversion rate on CO2 and H2 was found.

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Induced changes in ceria by thermal treatments under vacuum or hydrogen

Cited by 243 publications

References 9 publications

NO reduction by CO over gold catalysts based on ceria supports, prepared by mechanochemical activation, modified by Me3+ (Me = Al or lanthanides): Effect of water in the feed gas

NO reduction by CO over gold catalysts based on ceria supports, prepared by mechanochemical activation, modified by Me3+ (Me = Al or lanthanides): Effect of water in the feed gas

Understanding of the oxygen activation on ceria- and ceria/alumina-supported gold catalysts: a study combining 18O/16O isotopic exchange and EPR spectroscopy

Water gas shift reaction over Cu catalyst supported by mixed oxide materials for fuel cell application

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