A5061932210- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Catalytic Processes in Materials Science
- X-ray Spectroscopy and Fluorescence Analysis
- Material Dynamics and Properties
- Electron and X-Ray Spectroscopy Techniques
- Quantum, superfluid, helium dynamics
- Catalysis and Oxidation Reactions
- nanoparticles nucleation surface interactions
- Electrocatalysts for Energy Conversion
- Phase Equilibria and Thermodynamics
- Atomic and Molecular Physics
- Surface Chemistry and Catalysis
- Molecular Junctions and Nanostructures
- Inorganic Fluorides and Related Compounds
- Photochemistry and Electron Transfer Studies
- CO2 Reduction Techniques and Catalysts
- Theoretical and Computational Physics
- Social and Educational Sciences
- Molecular spectroscopy and chirality
- X-ray Diffraction in Crystallography
- Mass Spectrometry Techniques and Applications
- Spectroscopy and Laser Applications
- NMR spectroscopy and applications
- Machine Learning in Materials Science
Stockholm University
2016-2025
AlbaNova
2016-2025
SLAC National Accelerator Laboratory
2016-2022
KTH Royal Institute of Technology
2000-2022
Fritz Haber Institute of the Max Planck Society
2022
ORCID
2020
Belarusian State University
2019
Bolin Centre for Climate Research
2019
Stockholm Environment Institute
2019
University of Nottingham
2018
X-ray absorption spectroscopy and x-ray Raman scattering were used to probe the molecular arrangement in first coordination shell of liquid water. The local structure is characterized by comparison with bulk surface ordinary hexagonal ice Ih calculated spectra. Most molecules water are two hydrogen-bonded configurations one strong donor acceptor hydrogen bond contrast four tetrahedral ice. Upon heating from 25 degrees C 90 C, 5 10% change environments configurations. Our findings consistent...
Small-angle X-ray scattering (SAXS) is used to demonstrate the presence of density fluctuations in ambient water on a physical length-scale ≈1 nm; this retained with decreasing temperature while magnitude enhanced. In contrast, normal liquid, such as CCl 4 , exhibits no enhancement temperature, also case for from molecular dynamics simulations under conditions. Based emission spectroscopy and Raman data we propose that difference contrast SAXS due between tetrahedral-like hydrogen-bond...
We address the adsorption of water on Pt(111) using x-ray absorption, emission, and photoelectron spectroscopy along with calculations in framework density functional theory. Using direct relationship between electronic structure adsorbate geometry, we show that first layer all molecules bind directly to surface each other through in-layer H bonds without dissociation, creating a nearly flat overlayer. The are adsorbed alternating metal-oxygen (M-O) metal-hydrogen (M-HO) bonds.
We explore the utility of density-functional theory (DFT) in conjunction with transition-potential (TP) method to simulate x-ray-absorption spectra. Calculations on a set small carbon-containing molecules and chemisorbed species show that this provides viable option for obtaining excitation energies oscillator strengths close experimental accuracy core-valence transitions. Systematic variations energy positions intensities different spectra test series have been investigated, comparison is...
Robust methods to tune the unique electronic properties of graphene by chemical modification are in great demand due potential two dimensional material impact a range device applications. Here we show that carbon and nitrogen core-level resonant X-ray spectroscopy is sensitive probe bonding structure dopants introduced single-sheet films. In conjunction with density functional theory based calculations, able obtain detailed picture bond types doped at sub-percent level. We different N-bond...
Four recent x-ray diffraction measurements of ambient liquid water are reviewed here. Each these represents a significant development the technique applied to study water. Sources uncertainty from statistical noise, Q-range, Compton scattering, and self-scattering discussed. The oxygen-hydrogen contribution measured scattering pattern was subtracted using literature data yield an experimental determination, with error bars, oxygen-oxygen pair-distribution function, gOO(r), which essentially...
Copper electrocatalysts derived from an oxide have shown extraordinary electrochemical properties for the carbon dioxide reduction reaction (CO2RR). Using in situ ambient pressure X-ray photoelectron spectroscopy and quasi electron energy-loss a transmission microscope, we show that there is substantial amount of residual oxygen nanostructured, oxide-derived copper but no oxide. On basis these findings combination with density functional theory simulations, propose subsurface changes...
Femtosecond x-ray laser pulses are used to probe the carbon monoxide (CO) oxidation reaction on ruthenium (Ru) initiated by an optical pulse. On a time scale of few hundred femtoseconds, pulse excites motions CO and oxygen (O) surface, allowing reactants collide, and, with transient close picosecond (ps), new electronic states appear in O K-edge absorption spectrum. Density functional theory calculations indicate that these result from changes adsorption site bond formation between...
Significance The importance of a molecular-level understanding the properties, structure, and dynamics liquid water is recognized in many scientific fields. It has been debated whether observed high- low-density amorphous ice forms are related to two distinct forms. Here, we study experimentally structure high-density as it relaxes into form. unique aspect this work combination X-ray methods, where wide-angle scattering provides evidence for at atomic level photon-correlation spectroscopy...
Abstract Glycerol electrolysis affords a green and energetically favorable route for the production of value‐added chemicals at anode H 2 in parallel cathode. Here, facile method trapping Pt nanoparticles oxygen vacancies molybdenum oxide (MoO x ) nanosheets, yielding high‐performance MoO /Pt composite electrocatalyst both glycerol oxidation reaction (GOR) hydrogen evolution (HER) alkaline electrolytes, is reported. Combined electrochemical experiments theoretical calculations reveal...
Abstract Electrochemical valorization of biomass waste (e.g., glycerol) for production value‐added products (such as formic acid) in parallel with hydrogen holds great potential developing renewable and clean energy sources. Here, a synergistic effort between theoretical calculations at the atomic level experiments to predict validate promising oxide catalyst glycerol oxidation reaction (GOR) are reported, providing good example designing novel, cost‐effective, highly efficient...
Abstract Density functional theory predictions of binding energies and reaction barriers provide invaluable data for analyzing chemical transformations in heterogeneous catalysis. For high accuracy, effects band structure coverage, as well the local bond strength both covalent non-covalent interactions, must be reliably described much focus has been put on improving functionals to this end. Here, we show that a correction from higher-level calculations small metal clusters can applied...
We have studied the electronic structure of liquid water using x-ray absorption spectroscopy at oxygen K edge. Since process takes less than a femtosecond, it allows probing molecular orbital frozen, local geometries molecules timescale that has not previously been accessible. Our results indicate is significantly different from solid and gaseous forms, resulting in pronounced pre-edge feature below main edge spectrum. Theoretical calculations these spectra suggest this originates specific...
High resolution, vibrationally resolved, near-edge x-ray absorption fine structure (NEXAFS) spectra at the C 1s and N ionization thresholds of pyridine deuterated d5-pyridine in gas phase have been recorded. The high resolution 65 meV (150 meV) s (N 1s) reveals vibrational structures spectra. Detailed ab initio density functional theory (DFT) calculations were performed to interpret experimental assign observed peaks. In particular we focused on previously unexplained intensity ratio for two...
It is shown using x-ray photoelectron spectroscopy that water adsorbed either nondissociatively or partially dissociatively on Ru(001) under ultrahigh vacuum conditions. We found an activated dissociation process with a barrier slightly larger than of desorption. A difference in barriers between H2O and D2O explains the anomalous isotope effects thermal Previous theoretical experimental disagreements can be rationalized based electron beam-induced overlayer earlier underestimation barrier.