scholarly journals Prospects for the expansion of standing wave ambient pressure photoemission spectroscopy to reactions at elevated temperatures

2022 ◽  
Vol 40 (1) ◽  
pp. 013207
Author(s):  
Osman Karslıoğlu ◽  
Lena Trotochaud ◽  
Farhad Salmassi ◽  
Eric M. Gullikson ◽  
Andrey Shavorskiy ◽  
...  
Keyword(s):  
Standing Wave ◽  
Elevated Temperatures ◽  
Ambient Pressure ◽  
Photoemission Spectroscopy

scholarly journals Layer-resolved many-electron interactions in delafossite PdCoO2 from standing-wave photoemission spectroscopy

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Qiyang Lu ◽  
Henrique Martins ◽  
Juhan Matthias Kahk ◽  
Gaurab Rimal ◽  
Seongshik Oh ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Standing Wave ◽  
Three Dimensional ◽  
Photoemission Spectroscopy ◽  
Electronic Coupling ◽  
Many Body ◽  
X Ray ◽  
Charge Transfer Excitons ◽  
Many Body Interactions ◽  
Electron Interactions

AbstractWhen a three-dimensional material is constructed by stacking different two-dimensional layers into an ordered structure, new and unique physical properties can emerge. An example is the delafossite PdCoO2, which consists of alternating layers of metallic Pd and Mott-insulating CoO2 sheets. To understand the nature of the electronic coupling between the layers that gives rise to the unique properties of PdCoO2, we revealed its layer-resolved electronic structure combining standing-wave X-ray photoemission spectroscopy and ab initio many-body calculations. Experimentally, we have decomposed the measured VB spectrum into contributions from Pd and CoO2 layers. Computationally, we find that many-body interactions in Pd and CoO2 layers are highly different. Holes in the CoO2 layer interact strongly with charge-transfer excitons in the same layer, whereas holes in the Pd layer couple to plasmons in the Pd layer. Interestingly, we find that holes in states hybridized across both layers couple to both types of excitations (charge-transfer excitons or plasmons), with the intensity of photoemission satellites being proportional to the projection of the state onto a given layer. This establishes satellites as a sensitive probe for inter-layer hybridization. These findings pave the way towards a better understanding of complex many-electron interactions in layered quantum materials.

Near ambient pressure photoemission spectroscopy of metal and semiconductor surfaces

2015 ◽  
Vol 12 (3) ◽  
pp. 259-262 ◽  
Author(s):  
Iain D. Baikie ◽  
Angela Grain ◽  
James Sutherland ◽  
Jamie Law
Keyword(s):  
Ambient Pressure ◽  
Photoemission Spectroscopy ◽  
Semiconductor Surfaces

Hard x-ray photoemission spectroscopy on the trilayer system MgO/Au/Fe using standing-wave excitation

2013 ◽  
Vol 46 (37) ◽  
pp. 375001 ◽  
Author(s):  
S Döring ◽  
F Schönbohm ◽  
U Berges ◽  
D E Bürgler ◽  
C M Schneider ◽  
...  
Keyword(s):  
Standing Wave ◽  
Photoemission Spectroscopy ◽  
Wave Excitation ◽  
X Ray

scholarly journals Cover Picture: Ambient Pressure Photoemission Spectroscopy Reveals the Mechanism of Carbon Soot Oxidation in Ceria-Based Catalysts (ChemCatChem 17/2016)

ChemCatChem ◽  
2016 ◽  
Vol 8 (17) ◽  
pp. 2733-2733
Author(s):  
Lluís Soler ◽  
Albert Casanovas ◽  
Carlos Escudero ◽  
Virginia Pérez-Dieste ◽  
Eleonora Aneggi ◽  
...  
Keyword(s):  
Ambient Pressure ◽  
Soot Oxidation ◽  
Photoemission Spectroscopy ◽  
Carbon Soot

Observation of in situ oxidation dynamics of vanadium thin film with ambient pressure X-ray photoemission spectroscopy

2016 ◽  
Vol 120 (20) ◽  
pp. 205305 ◽  
Author(s):  
Geonhwa Kim ◽  
Joonseok Yoon ◽  
Hyukjun Yang ◽  
Hojoon Lim ◽  
Hyungcheol Lee ◽  
...  
Keyword(s):  
Thin Film ◽  
Ambient Pressure ◽  
Photoemission Spectroscopy ◽  
In Situ Oxidation ◽  
X Ray

scholarly journals Breaking Simple Scaling Relations Through Metal-Oxide Interactions: Understanding Room Temperature Activation of Methane on M-CeO2 (M= Pt, Ni or Co) Interfaces

2020 ◽  
Author(s):  
Pablo Lustemberg ◽  
Feng Zhang ◽  
Ramón A. Gutiérrez ◽  
Pedro J. Ramírez ◽  
Sanjaya D. Senanayake ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Ambient Pressure ◽  
Scaling Relations ◽  
Time Resolved ◽  
X Ray ◽  
Metal Support ◽  
Simple Scaling

The clean activation of methane at low temperatures remains an eminent challenge and a field of competitive research. In particular, on late transition metal surfaces such as Pt(111) or Ni(111), elevated temperatures are necessary to activate the hydrocarbon molecule, but a massive deposition of carbon makes the metal surface useless for catalytic activity. However, on very low-loaded M/CeO2 (M= Pt, Ni, or Co) surfaces, the dissociation of methane occurs at room temperature, which is unexpected considering simple linear scaling relationships. This intriguing phenomenon has been studied using a combination of experimental techniques (ambient-pressure X-ray photoelectron spectroscopy, time-resolved X-ray diffraction and X-ray absorption spectroscopy) and density functional theory-based calculations. The experimental and theoretical studies show that the size and morphology of the supported nanoparticles together with strong metal-support interactions are behind the deviations from the scaling relations. These findings point toward a possible strategy to circumvent scaling relations, producing active and stable catalysts which can be employed for methane activation and conversion. <br>

In situ investigation of water on MXene interfaces

2021 ◽  
Vol 118 (49) ◽  
pp. e2108325118
Author(s):  
Wahid Zaman ◽  
Ray A. Matsumoto ◽  
Matthew W. Thompson ◽  
Yu-Hsuan Liu ◽  
Yousuf Bootwala ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Water Adsorption ◽  
Elevated Temperatures ◽  
Ambient Pressure ◽  
Transition Metal Carbide ◽  
Water Removal ◽  
Water Mobility ◽  
Level Control ◽  
X Ray ◽  
In Situ Investigation

A continuum of water populations can exist in nanoscale layered materials, which impacts transport phenomena relevant for separation, adsorption, and charge storage processes. Quantification and direct interrogation of water structure and organization are important in order to design materials with molecular-level control for emerging energy and water applications. Through combining molecular simulations with ambient-pressure X-ray photoelectron spectroscopy, X-ray diffraction, and diffuse reflectance infrared Fourier transform spectroscopy, we directly probe hydration mechanisms at confined and nonconfined regions in nanolayered transition-metal carbide materials. Hydrophobic (K+) cations decrease water mobility within the confined interlayer and accelerate water removal at nonconfined surfaces. Hydrophilic cations (Li+) increase water mobility within the confined interlayer and decrease water-removal rates at nonconfined surfaces. Solutes, rather than the surface terminating groups, are shown to be more impactful on the kinetics of water adsorption and desorption. Calculations from grand canonical molecular dynamics demonstrate that hydrophilic cations (Li+) actively aid in water adsorption at MXene interfaces. In contrast, hydrophobic cations (K+) weakly interact with water, leading to higher degrees of water ordering (orientation) and faster removal at elevated temperatures.

scholarly journals Concentration and chemical-state profiles at heterogeneous interfaces with sub-nm accuracy from standing-wave ambient-pressure photoemission

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Slavomír Nemšák ◽  
Andrey Shavorskiy ◽  
Osman Karslioglu ◽  
Ioannis Zegkinoglou ◽  
Arunothai Rattanachata ◽  
...  
Keyword(s):  
Standing Wave ◽  
Ambient Pressure ◽  
Chemical State ◽  
Heterogeneous Interfaces
Sign in / Sign up

Export Citation Format

Share Document