<b>
                     <i>Operando</i>
                  </b> study of Pd(100) surface during CO oxidation using ambient pressure x-ray photoemission spectroscopy

Yu, Youngseok; Kim, Dongwoo; Lim, Hojoon; Kim, Geonhwa; Koh, Yoobin Esther; Kim, Dae Hyun; Ueda, Kohei; Hiwasa, Satoru; Mase, Kenji; Bournel, Fabrice; Gallet, Jean Jacques; Rochet, F.; Crumlin, Ethan J.; Ross, Philip N.; Kondoh, Hiroshi; Noh, Do Young; Mun, Bongjin Simon

doi:10.1063/1.5081066

Cited by 12 publications

(6 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“… 28 , 29 For the oxide peak, a Gaussian–Lorentzian peak shape was used at 336.5 (±0.05) eV. The peak positions and assignments of the metal and oxide peaks are in good agreement with previous studies 30 , 31 after correction for the recoil effect caused by the high-energy X-rays. 32 …”

supporting

confidence: 80%

“…The fitting included the Pd 3d 5/2 metal peak, an asymmetric shape that incorporates the asymmetry expected for a metal peak, and the Pd CO 2√2×√2 adsorbed peak based on the pure metal, centered at 334.9 (±0.05) eV. , For the oxide peak, a Gaussian–Lorentzian peak shape was used at 336.5 (±0.05) eV. The peak positions and assignments of the metal and oxide peaks are in good agreement with previous studies , after correction for the recoil effect caused by the high-energy X-rays …”

supporting

confidence: 77%

See 1 more Smart Citation

The Structure of the Active Pd State During Catalytic Carbon Monoxide Oxidization

Goodwin

Shipilin

Albertin

et al. 2021

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

Using grazing incidence X-rays and X-ray photoelectron spectroscopy during the mass transfer limited catalytic oxidation of CO, the long-range surface structure of Pd(100) was investigated. Under the reaction conditions of 50:4 O 2 to CO, 300 mbar pressure, and temperatures between 200 and 450 °C, the surface structure resulting from oxidation and the subsequent oxide reduction was elucidated. The reduction cycle was halted, and while under reaction conditions, angle-dependent X-ray photoelectron spectroscopy close to the critical angle of Pd and modeling of the data was performed. Two proposed models for the system were compared. The suggestion with the metallic islands formed on top of the oxide island was shown to be consistent with the data.

show abstract

supporting

confidence: 80%

supporting

confidence: 77%

The Structure of the Active Pd State During Catalytic Carbon Monoxide Oxidization

Goodwin

Shipilin

Albertin

et al. 2021

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

show abstract

“…By increasing the temperature, the CO molecules desorb, the light-off for the reaction is reached, and Pd(100) is highly active. For a broad partial pressure range of CO and O 2, the surface oxide is reported to be observed after the light-off. − The thicker PdO oxide formation has also been observed in the highly active phase when more oxidizing conditions are applied. , If the reaction conditions are switched from oxygen-rich to CO rich conditions, a metallic Pd surface is observed …”

Section: Introductionmentioning

confidence: 99%

Bridging the Pressure Gap in CO Oxidation

et al. 2021

View full text Add to dashboard Cite

Performing fundamental operando catalysis studies under realistic conditions is a key to further develop and increase the efficiency of industrial catalysts. Operando X-ray photoelectron spectroscopy (XPS) experiments have been limited to pressures, and the relevance for industrial applications has been questioned. Herein, we report on the CO oxidation experiment on Pd(100) performed at a total pressure of 1 bar using XPS. We investigate the light-off regime and the surface chemical composition at the atomistic level in the highly active phase. Furthermore, the observed gas-phase photoemission peaks of CO 2 , CO, and O 2 indicate that the kinetics of the reaction during the light-off regime can be followed operando , and by studying the reaction rate of the reaction, the activation energy is calculated. The reaction was preceded by an in situ oxidation study in 7% O 2 in He and a total pressure of 70 mbar to confirm the surface sensitivity and assignment of the oxygen-induced photoemission peaks. However, oxygen-induced photoemission peaks were not observed during the reaction studies, but instead, a metallic Pd phase is present in the highly active regime under the conditions applied. The novel XPS setup utilizes hard X-rays to enable high-pressure studies, combined with a grazing incident angle to increase the surface sensitivity of the measurement. Our findings demonstrate the possibilities of achieving chemical information of the catalyst, operando , on an atomistic level, under industrially relevant conditions.

show abstract

“…The binding energies of gas molecules can serve as a way to measure how the work function of the sample varies [19,26]. Thus, the Ar 2p binding energies were investigated together with the components of the 2D MoS 2 monolayer and MoS 2 /Gr vdW 2D HT.…”

Section: Resultsmentioning

confidence: 99%

Revealing unique energy level alignment at graphene/MoS₂ 2-dimensional layered junction using in situ ambient pressure x-ray photoelectron spectroscopy

et al. 2020

View full text Add to dashboard Cite

The chemical/electronic structures of a 2-dimensional (2D) molybdenum disulfide (MoS2) monolayer were characterized using ambient pressure x-ray photoelectron spectroscopy (APXPS) under various gas environments. APXPS results captured the binding energy shifts for the MoS2 chemical states that represent the electronic-structure of the 2D MoS2 monolayer in a real gas environment. The effect of the presence of a 2D graphene (Gr) layer on the properties of the 2D MoS2 layer was simultaneously characterized. When coating a Gr layer on the MoS2 layer, electron injection from MoS2 to Gr occurs due to the Schottky barrier at the interface. As a result, the Gr layer and MoS2 layer attain relatively more n-type and p-type characteristics, respectively, compared to when they exist separately. The hole-injection barrier, formed between the MoS2 layer and the SiO2 substrate, is lower by about 0.3 eV in the Gr/MoS2/SiO2 structure compared to that in the MoS2/SiO2 structure. This gap in the energy level alignments is stable so that there is no change in Ar, N2, O2, and CO2 environments. Taken together, our results not only present an appropriate methodology for fabricating 2D material-based device components, but also suggest the need for consideration of the charge transfer at the MoS2/Gr junction when applied to a practical device.

show abstract

Operando study of Pd(100) surface during CO oxidation using ambient pressure x-ray photoemission spectroscopy

Cited by 12 publications

References 33 publications

The Structure of the Active Pd State During Catalytic Carbon Monoxide Oxidization

The Structure of the Active Pd State During Catalytic Carbon Monoxide Oxidization

Bridging the Pressure Gap in CO Oxidation

Revealing unique energy level alignment at graphene/MoS₂ 2-dimensional layered junction using in situ ambient pressure x-ray photoelectron spectroscopy

Contact Info

Product

Resources

About

Operando study of Pd(100) surface during CO oxidation using ambient pressure x-ray photoemission spectroscopy

Cited by 12 publications

References 33 publications

The Structure of the Active Pd State During Catalytic Carbon Monoxide Oxidization

The Structure of the Active Pd State During Catalytic Carbon Monoxide Oxidization

Bridging the Pressure Gap in CO Oxidation

Revealing unique energy level alignment at graphene/MoS2 2-dimensional layered junction using in situ ambient pressure x-ray photoelectron spectroscopy

Contact Info

Product

Resources

About

Revealing unique energy level alignment at graphene/MoS₂ 2-dimensional layered junction using in situ ambient pressure x-ray photoelectron spectroscopy