The reactions of water vapour on the surfaces of stoichiometric and reduced uranium dioxide: A high resolution XPS study

Senanayake, Sanjaya D.; Waterhouse, Geoffrey I. N.; Chan, Anthony; Madey, Theodore E.; Mullins, David R.; Idriss, Hicham

doi:10.1016/j.cattod.2006.07.040

Cited by 63 publications

(52 citation statements)

References 24 publications

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“…At 150 K there is an abrupt decomposition as the ice layers melt, with a more pronounced peak at 531.4 eV. At 175 K, the ice layers (533.9 eV) has desorbed completely leaving the most predominant peak at 531.4 eV, which can be assigned to OH derived from the dissociation of O-H bonds in H 2 O [20,21]. The peak area of the 531.4 eV peak is approximately two times larger than that of the peak at 529.…”

Section: Adsorption Of Co On Cu(111)mentioning

confidence: 96%

Intermediates Arising from the Water–Gas Shift Reaction over Cu Surfaces: From UHV to Near Atmospheric Pressures

et al. 2015

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The water-gas shift (WGS) reaction is a key process to the production of high purity H-2 from gas streams rich in CO. The identification of the WGS reaction mechanism and the probable stable intermediates is critical to design the catalyst structure, optimize composition and tune reaction kinetics/thermodynamics to achieve the optimum selectivity and activity. In this study, first the WGS reaction steps on Cu(111) have been studied using X-ray photoelectron spectroscopy (XPS) and infrared reflection absorption spectroscopy under ultra-high vacuum (UHV) conditions. Then the interactions of H2O with CO on Cu(111) have been studied under elevated pressures (90 mTorr CO + 30 mTorr H2O) at 300-575 K with ambient pressure XPS. Under UHV conditions, non-dissociative adsorption of H2O on Cu(111) and Cu2O/Cu(111) was observed. Whereas H2O readily dissociates, by breaking the O-H bond on a chemisorbed O layer on Cu(111) to form OH species. Even though this OH interacts with adsorbed CO, it does not react to form any associative intermediate and simply desorbs as H2O at 275 K under UHV conditions. At ambient pressures, no associative intermediates species, only CO and OH, were observed in the reaction of CO with H2O although the catalytic production of H-2 can be detected under these conditions. Since intermediate species other than CO and OH were not observed on Cu(111) under reaction conditions, we concluded that the redox mechanism is the dominant WGS pathway on Cu(111). The coupling of Cu to an oxide, Cu-CeO2 catalyst, or a carbide, Cu-TiC catalyst, favors an associative mechanism and produces a very large increase in the rate for the production of H-2 through the WGS

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Section: Adsorption Of Co On Cu(111)mentioning

confidence: 96%

Intermediates Arising from the Water–Gas Shift Reaction over Cu Surfaces: From UHV to Near Atmospheric Pressures

et al. 2015

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“…Owing to its technological relevance in the nuclear power industry and its significance from fundamental scientific point of view, uranium dioxide is intensely studied both experimentally [1][2][3][4][5] and theoretically [6][7][8]. One of the challenging research topics about uranium dioxide is the reactions of uranium dioxide with water, which it is associated with many fundamental phenomena related to hydrogen production [9,10], corrosion [11] and modifications of crystal morphologies [12,13].…”

Section: Introductionmentioning

confidence: 99%

First-principles study of water adsorption and dissociation on the UO2 (1 1 1), (1 1 0) and (1 0 0) surfaces

Tang

Lan

Zhao

et al. 2014

Journal of Nuclear Materials

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“…doi:10.1016/j.jnucmat.2007. 12.007 and the use of polycrystalline versus single-crystal substrates [16,[19][20][21]27]. The presence of defects or the use of polycrystalline materials tends to favor the dissociation of water [19] which is important because the interaction of water with actinide-oxide surfaces (e.g.…”

Section: Introductionmentioning

confidence: 99%

Corrosion of UO2 and ThO2: A quantum-mechanical investigation

Skomurski

Shuller

Ewing

et al. 2008

Journal of Nuclear Materials

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The reactions of water vapour on the surfaces of stoichiometric and reduced uranium dioxide: A high resolution XPS study

Cited by 63 publications

References 24 publications

Intermediates Arising from the Water–Gas Shift Reaction over Cu Surfaces: From UHV to Near Atmospheric Pressures

Intermediates Arising from the Water–Gas Shift Reaction over Cu Surfaces: From UHV to Near Atmospheric Pressures

First-principles study of water adsorption and dissociation on the UO2 (1 1 1), (1 1 0) and (1 0 0) surfaces

Corrosion of UO2 and ThO2: A quantum-mechanical investigation

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