Angular distribution of desorbing carbon dioxide produced in two processes on a stepped platinum (557) surface

Ohno, Yuichi; Sánchez, J. R.; Lesar, Antonija; Yamanaka, Toshiro; Matsushima, Toshiyasu

doi:10.1016/s0039-6028(97)00147-7

Cited by 21 publications

(20 citation statements)

References 35 publications

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“…For example, early work by Ohno et al. showed that CO 2 forms from the reaction of adsorbed CO with adsorbed O atoms on flat terraces, but with adsorbed O 2 molecules on steps 40…”

Section: Co Interaction With Monometallic Systems: the Example Of Plamentioning

confidence: 99%

“…For example, early work by Ohno et al showed that CO 2 forms from the reaction of adsorbed CO with adsorbed O atoms on flat terraces, but with adsorbed O 2 molecules on steps. [40] Energy barriers also depend on the presence of steps, kinks and defects. By using sum-frequency generation operating under 40 Torr, CO dissociation temperature was shown to be lower (500 K) on the less stable Pt(100) surface, which is prone to surface roughening, than on more stable Pt(111) surface (673 K).…”

Section: Stepped Surfacesmentioning

confidence: 99%

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Carbon Monoxide‐Induced Dynamic Metal‐Surface Nanostructuring

Carenco

2014

Chemistry A European J

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Carbon monoxide is a ubiquitous molecule in surface science, materials chemistry, catalysis and nanotechnology. Its interaction with a number of metal surfaces is at the heart of major processes, such as Fischer-Tropsch synthesis or fuel-cell optimization. Recent works, coupling structural and nanoscale in situ analytic tools have highlighted the ability of metal surfaces and nanoparticles to undergo restructuring after exposure to CO under fairly mild conditions, generating nanostructures. This Minireview proposes a brief overview of recent examples of such nanostructuring, which leads to a discussion about the driving force in reversible and non-reversible situations.

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“…For example, early work by Ohno et al. showed that CO 2 forms from the reaction of adsorbed CO with adsorbed O atoms on flat terraces, but with adsorbed O 2 molecules on steps 40…”

Section: Co Interaction With Monometallic Systems: the Example Of Plamentioning

confidence: 99%

Section: Stepped Surfacesmentioning

confidence: 99%

Carbon Monoxide‐Induced Dynamic Metal‐Surface Nanostructuring

Carenco

2014

Chemistry A European J

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“…14,15,16 This surface was chosen since various stepped platinum surfaces have been shown to dissociate CO under UHV conditions. 8,17,18 It was expected that the stepped Pt(557) surface would dissociate CO at lower temperatures than was observed for Pt(111) when exposed to 40 Torr of CO.…”

Section: Co Adsorption and Decomposition On Pt(557)mentioning

confidence: 99%

“…Three SFG spectra were for the terrace sites, and at 498K for step sites. 19,15 Since only one feature is observed in the SFG spectrum at saturation coverage, the SFG spectrum is indicative of a twodimensional domain composed of CO molecules adsorbed at both step and terrace sites. 20 To determine whether just CO adsorbed on stepped edges could be observed by SFG, the surface was flashed sequentially to higher temperatures and cooled back down to 293K at which point SFG spectra were acquired ( Figure 6 This could explain why the peak is broader than the peak observed directly after the 4L exposure.…”

Section: Co Adsorption and Decomposition On Pt(557)mentioning

confidence: 99%

Effect of surface structure on catalytic reactions: A sum frequency generation surface vibrational spectroscopy study

McCrea¹

2001

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Using Sum Frequency Generation (SFG) and gas chromatography (GC), molecular level investigations of catalytic reactions were performed on platinum single crystal surfaces. The SFG spectra and GC data was correlated to elucidate the nature of active species present on the surface under high-pressure catalytic reactions.The effect of structure sensitivity and insensitivity of several catalytic reactions were investigated. Ethylene hydrogenation, a structure insensitive reaction, was performed over both Pt(111) and Pt(100). The reaction rate was the same on both surfaces (11 molecules/site/sec 300 K), although the relative concentrations of surface species were observed to be different. Both ethylidyne and di-σ bonded ethylene, strongly adsorbed species, were present on the surface under reaction conditions. These species were not responsible for catalytic turnover. Weekly adsorbed species 2 such as π-bonded ethylene and ethyl intermediates are responsible for surface turnover as revealed by SFG.Cyclohexene hydrogenation and dehydrogenation were also performed on Pt(100) and Pt(111). Cyclohexene dehydrogenation is structure sensitive and it was found that the rate of dehydrogenation was higher on the (100) surface of platinum.From SFG results, it was concluded that dehydrogenation can proceed through both 1,3-and 1,4-cyclohexadiene intermediates, although, the rate proceeds faster through the 1,3-intermediate. The rate dehydrogenation on Pt(100) was higher because there was a higher concentration of 1,3-cyclohexadiene on the Pt(100) surface as compared to the (111) surface.By exposing Pt(111), Pt(100), and Pt(557) single crystal surfaces to high pressures of CO, it was found that Pt-carbonyls could be produced leading to the dissociation of CO. In addition, it was found that CO dissociation was structure sensitive when the crystals were exposed to 40 Torr of CO. The Pt(100) surface was the most active and showed dissociation at 500 K, while the Pt(111) surface was the least active with a dissociation temperature of 673 K. Pt(557) exhibited a dissociation temperature at 548 K, between the two other surfaces. Surface roughness was found to affect the temperature of dissociation and Pt-carbonyls were responsible for roughening of the surface. Pt(100) was the most active because the surface reconstructs and roughens at a lower temperature than the other two surfaces. In addition, CO oxidation experiments were performed on all three surfaces and the ignition temperature followed 3 the same trend observed for CO dissociation. This indicates that CO dissociation is important for the onset of ignition.An in depth study of CO oxidation on Pt(557) was performed on both clean and carbon-covered prepared surfaces. Under excess O 2 and excess CO conditions, a clean prepared platinum surface will remain carbon free below and above ignition. It was found that a carbon oxide species was formed on carbon covered platinum surfaces.The carbon oxide species was also found to form on clean prepared platinum below ignition when it was e...

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“…Early HV and UHV experiments found a higher activation energy at steps compared to terraces. 37,[55][56][57][58][59] However, the high oxygen dissociation probability at steps may be ineffective due to an equally low CO oxidation rate, making it a priori unclear whether steps are beneficial for the catalytic efficiency of the surface. 55 Only a few experiments have been done on vicinal surfaces at millibar pressures, which prove the presence of structural instabilities 42,60 and volatile oxides, 52 pointing to diverse reaction mechanisms and structural/chemical interplay.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Oxidation of CO on a Curved Pt(111) Surface: Simultaneous Ignition at All Facets Through a Transient CO-O Complex

García-Martínez¹,

́andez²,

Simonovi³

et al. 2020

Preprint

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We combine PLIF and NAP-XPS to investigate the CO oxidation reaction at vicinal Pt(111) surfaces in the millibar regime, using a curved sample. We find that the catalytic activation of Pt occurs in all vicinal planes simultaneously,<br>irrespectively of the reaction parameters. The systematic analysis of chemical species across the entire curved surface provides the clues for this surprising behavior. As the surface CO concentration decreases when approaching ignition, minor amounts of oxygen build up at both steps and (111) terraces. First-principles theory indicates that the latter is forming a CO-Pt-O complex that binds CO molecules to terraces strongly, leveling its adsorption energy to that of low-coordinated steps, and explaining why CO abruptly desorbs at the same temperature along the di erent crystal facets that make up the curved Pt surface.

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Angular distribution of desorbing carbon dioxide produced in two processes on a stepped platinum (557) surface

Cited by 21 publications

References 35 publications

Carbon Monoxide‐Induced Dynamic Metal‐Surface Nanostructuring

Carbon Monoxide‐Induced Dynamic Metal‐Surface Nanostructuring

Effect of surface structure on catalytic reactions: A sum frequency generation surface vibrational spectroscopy study

Catalytic Oxidation of CO on a Curved Pt(111) Surface: Simultaneous Ignition at All Facets Through a Transient CO-O Complex

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