Chemisorbed Oxygen on Au(111) Produced by a Novel Route:  Reaction in Condensed Films of NO<sub>2</sub> + H<sub>2</sub>O

Wang, Jiang; Voß, M.; Busse, H.; Koel, Bruce E.

doi:10.1021/jp981028o

Cited by 57 publications

(83 citation statements)

References 16 publications

(30 reference statements)

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“…Based on their calibration, the maximum coverage of oxygen atoms deposited using our method was calculated to be~0.4 ML. This value is close to the saturation coverage of atomic oxygen deposited from the reaction of NO 2 and H 2 O (h O = 0.42 ML), [39] but less than that obtained from ozone exposure (h O = 1.2 ML) [41]. We corroborate the coverage estimate with temperature programmed desorption measurements of O 2 yields relative to those measured for a saturation coverage of atomic oxygen from ozone exposure.…”

Section: Interaction Of Sulfur and Oxygen With Au(111) At Low Coveragesupporting

confidence: 68%

“…Recently, Mullins and coworkers deposited oxygen atoms on Au(111) using a supersonic beam of oxygen atoms produced from a radio frequency-generated plasma source [37]. Atomic oxygen has also been prepared on Au(111) by exposure to ozone (O 3 ), [16] thermal dissociation of gaseous O 2 using hot filaments, [38] O + sputtering, [15] and co-adsorption of NO 2 and H 2 O [39]. More recently, we developed a new method for depositing atomic oxygen on Au(111) by electron bombardment of NO 2 condensed on the Au(111) surface [40].…”

Section: Interaction Of Sulfur and Oxygen With Au(111) At Low Coveragementioning

confidence: 99%

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Reaction of Au(111) with Sulfur and Oxygen: Scanning Tunneling Microscopic Study

et al. 2005

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The reaction of sulfur and oxygen with the gold surface is important in many technological applications, including heterogeneous catalysis, corrosion, and chemical sensors. We have studied reactions on Au(111) using scanning tunneling microscopy (STM) in order to better understand the surface structure and the origin of gold's catalytic activity. We find that the Au(111) surface dynamically restructures during deposition of sulfur and oxygen and that these changes in structure promote the reactivity of Au with respect to SO 2 and O 2 dissociation. Specifically, the Au(111) herringbone reconstruction lifts when either S or O is deposited on the surface. We attribute this structural change to the reduction of tensile surface stress via charge redistribution by these electronegative adsorbates. This lifting of the reconstruction was accompanied by the release of gold atoms from the herringbone structure. At high coverage, clusters of gold sulfides or gold oxides form by abstraction of gold atoms from regular terrace sites of the surface. Concomitant with the restructuring is the release of gold atoms from the herringbone structure to produce a higher density of low-coordinated Au sites by forming serrated step edges or small gold islands. These undercoordinated Au atoms may play an essential role in the enhancement of catalytic activity of gold in reactions such as oxygen dissociation or SO 2 decomposition. Our results further elucidate the interaction between sulfur and oxygen and the Au(111) surface and indicate that the reactivity of Au nanoclusters on reducible metal oxides is probably related to the facile release of Au from the edges of these small islands. Our results provide insight into the sintering mechanism which leads to deactivation of Au nanoclusters and into the fundamental limitation in the edge definition in soft lithography using thiol-based self-assembled monolayers (SAMs) on Au. Furthermore, the enhanced reactivity of Au after release of undercoordinated atoms from the surface indicate a relatively insignificant role of an oxide support for high reactivity.

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Section: Interaction Of Sulfur and Oxygen With Au(111) At Low Coveragesupporting

confidence: 68%

Section: Interaction Of Sulfur and Oxygen With Au(111) At Low Coveragementioning

confidence: 99%

Reaction of Au(111) with Sulfur and Oxygen: Scanning Tunneling Microscopic Study

et al. 2005

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“…This isomerization is known to occur in solid matrices at low temperatures or high pressures, on ice and in solution, 101,[135][136][137][138][139][140][141][142][143][144][145][146][147][148][149][150] (although one study 151 observed only the symmetric form of N 2 O 4 on ice films). Koel and coworkers [148][149][150]152 proposed that this isomerization occurs via the free O-H groups on amorphous ice, and it is possible that a similar process occurs in the thin films studied here. Once formed, the asymmetric ONONO 2 Experimental and theoretical studies [153][154][155] of the reactions of gas phase clusters of hydrated NO + show that reaction to generate HONO occurs with four or more water molecules bound to NO + .…”

Section: Mechanisms and Modelsmentioning

confidence: 99%

The heterogeneous hydrolysis of NO2 in laboratory systems and in outdoor and indoor atmospheres: An integrated mechanism

Finlayson-Pitts

Wingen

Sumner

et al. 2002

Phys. Chem. Chem. Phys.

619

767

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The heterogeneous reaction of NO 2 with water on the surface of laboratory systems has been known for decades to generate HONO, a major source of OH that drives the formation of ozone and other air pollutants in urban areas and possibly in snowpacks. Previous studies have shown that the reaction is first order in NO 2 and in water vapor, and the formation of a complex between NO 2 and water at the air-water interface has been hypothesized as being the key step in the mechanism. We report data from long path FTIR studies in borosilicate glass reaction chambers of the loss of gaseous NO 2 and the formation of the products HONO, NO and N 2 O. Further FTIR studies were carried out to measure species generated on the surface during the reaction, including HNO 3 , N 2 O 4 and NO 2 + . We propose a new reaction mechanism in which we hypothesize that the symmetric form of the NO 2 dimer, N 2 O 4 , is taken up on the surface and isomerizes to the asymmetric form, ONONO 2 . The latter autoionizes to NO + NO 3 À , and it is this intermediate that reacts with water to generate HONO and surface-adsorbed HNO 3 . Nitric oxide is then generated by secondary reactions of HONO on the highly acidic surface. This new mechanism is discussed in the context of our experimental data and those of previous studies, as well as the chemistry of such intermediates as NO + and NO 2 + that is known to occur in solution. Implications for the formation of HONO both outdoors and indoors in real and simulated polluted atmospheres, as well as on airborne particles and in snowpacks, are discussed. A key aspect of this chemistry is that in the atmospheric boundary layer where human exposure occurs and many measurements of HONO and related atmospheric constituents such as ozone are made, a major substrate for this heterogeneous chemistry is the surface of buildings, roads, soils, vegetation and other materials. This area of reactions in thin films on surfaces (SURFACE ¼ Surfaces, Urban and Remote: Films As a Chemical Environment) has received relatively little attention compared to reactions in the gas and liquid phases, but in fact may be quite important in the chemistry of the boundary layer in urban areas.

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“…[70][71][72] In the case of HONO, the relatively large enthalpy of adsorption on the surface relative to water as discussed above suggests that the adsorbed species might already be partially or fully ionized.…”

mentioning

confidence: 98%

HONO decomposition on borosilicate glass surfaces: implications for environmental chamber studies and field experiments

Syomin

Finlayson-Pitts

2003

Phys. Chem. Chem. Phys.

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Nitrous acid (HONO) is the major source of OH in polluted urban atmospheres, so an understanding of its formation and loss processes both in urban atmospheres and in laboratory systems is important. Earlier studies over a limited range of conditions showed that HONO is taken up and undergoes reaction on surfaces. We report here a comprehensive set of studies of the decay of HONO and the formation of gas phase products over a range of initial HONO concentrations (0.1-11 ppm) at 1 atm pressure in N 2 at 296 K and 0, 20 and 50% relative humidity (RH), respectively. The loss of HONO and increase in gas phase products were measured over time using long path FTIR spectroscopy. Studies were carried out in an unconditioned borosilicate glass cell and in the same cell after pretreatment with dry gaseous nitric acid. In the HNO 3 -conditioned cell, the loss of HONO was first order at all values of relative humidity (RH), and NO 2 was the only significant gas phase product. For the unconditioned cell, the reaction order increased from first order at 0% RH to second order at 50% RH. The gas phase products at 0% RH were equal amounts of NO and NO 2 . The yield of NO increased to > 90% at 50% RH while the yield of NO 2 decreased to 10%. For both the unconditioned and the HNO 3 -treated cell, the rate of loss of HONO decreased with increasing RH. These results suggest that there is a competition between water, HONO and HNO 3 for surface sites. Displacement of HONO from the cell walls by water was observed in separate experiments. Possible mechanisms, and the implications for HONO formation in environmental chambers and in air, are discussed.

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Chemisorbed Oxygen on Au(111) Produced by a Novel Route: Reaction in Condensed Films of NO₂ + H₂O

Cited by 57 publications

References 16 publications

Reaction of Au(111) with Sulfur and Oxygen: Scanning Tunneling Microscopic Study

Reaction of Au(111) with Sulfur and Oxygen: Scanning Tunneling Microscopic Study

The heterogeneous hydrolysis of NO2 in laboratory systems and in outdoor and indoor atmospheres: An integrated mechanism

HONO decomposition on borosilicate glass surfaces: implications for environmental chamber studies and field experiments

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Chemisorbed Oxygen on Au(111) Produced by a Novel Route: Reaction in Condensed Films of NO2 + H2O

Cited by 57 publications

References 16 publications

Reaction of Au(111) with Sulfur and Oxygen: Scanning Tunneling Microscopic Study

Reaction of Au(111) with Sulfur and Oxygen: Scanning Tunneling Microscopic Study

The heterogeneous hydrolysis of NO2 in laboratory systems and in outdoor and indoor atmospheres: An integrated mechanism

HONO decomposition on borosilicate glass surfaces: implications for environmental chamber studies and field experiments

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Chemisorbed Oxygen on Au(111) Produced by a Novel Route: Reaction in Condensed Films of NO₂ + H₂O