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 ◽  
...  
2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Qiyang Lu ◽  
Henrique Martins ◽  
Juhan Matthias Kahk ◽  
Gaurab Rimal ◽  
Seongshik Oh ◽  
...  

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.


2015 ◽  
Vol 12 (3) ◽  
pp. 259-262 ◽  
Author(s):  
Iain D. Baikie ◽  
Angela Grain ◽  
James Sutherland ◽  
Jamie Law

2013 ◽  
Vol 46 (37) ◽  
pp. 375001 ◽  
Author(s):  
S Döring ◽  
F Schönbohm ◽  
U Berges ◽  
D E Bürgler ◽  
C M Schneider ◽  
...  

ChemCatChem ◽  
2016 ◽  
Vol 8 (17) ◽  
pp. 2733-2733
Author(s):  
Lluís Soler ◽  
Albert Casanovas ◽  
Carlos Escudero ◽  
Virginia Pérez-Dieste ◽  
Eleonora Aneggi ◽  
...  

2016 ◽  
Vol 120 (20) ◽  
pp. 205305 ◽  
Author(s):  
Geonhwa Kim ◽  
Joonseok Yoon ◽  
Hyukjun Yang ◽  
Hojoon Lim ◽  
Hyungcheol Lee ◽  
...  

2020 ◽  
Author(s):  
Pablo Lustemberg ◽  
Feng Zhang ◽  
Ramón A. Gutiérrez ◽  
Pedro J. Ramírez ◽  
Sanjaya D. Senanayake ◽  
...  

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>


2021 ◽  
Vol 118 (49) ◽  
pp. e2108325118
Author(s):  
Wahid Zaman ◽  
Ray A. Matsumoto ◽  
Matthew W. Thompson ◽  
Yu-Hsuan Liu ◽  
Yousuf Bootwala ◽  
...  

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.


2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Slavomír Nemšák ◽  
Andrey Shavorskiy ◽  
Osman Karslioglu ◽  
Ioannis Zegkinoglou ◽  
Arunothai Rattanachata ◽  
...  

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