scholarly journals Water Formation Reaction under Interfacial Confinement: Al0.25Si0.75O2 on O-Ru(0001)

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 183
Author(s):  
Jorge Cored ◽  
Mengen Wang ◽  
Nusnin Akter ◽  
Zubin Darbari ◽  
Yixin Xu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Reaction Pathway ◽  
Ambient Pressure ◽  
Inert Material ◽  
Formation Reaction ◽  
X Ray ◽  
Electrostatic Stabilization ◽  
Water Formation ◽  
Interfacial Confinement ◽  
Kinetics Of

Confined nanosized spaces at the interface between a metal and a seemingly inert material, such as a silicate, have recently been shown to influence the chemistry at the metal surface. In prior work, we observed that a bilayer (BL) silica on Ru(0001) can change the reaction pathway of the water formation reaction (WFR) near room temperature when compared to the bare metal. In this work, we looked at the effect of doping the silicate with Al, resulting in a stoichiometry of Al0.25Si0.75O2. We investigated the kinetics of WFR at elevated H2 pressures and various temperatures under interfacial confinement using ambient pressure X-ray photoelectron spectroscopy. The apparent activation energy was lower than that on bare Ru(0001) but higher than that on the BL-silica/Ru(0001). The apparent reaction order with respect to H2 was also determined. The increased residence time of water at the surface, resulting from the presence of the BL-aluminosilicate (and its subsequent electrostatic stabilization), favors the so-called disproportionation reaction pathway (*H2O + *O ↔ 2 *OH), but with a higher energy barrier than for pure BL-silica.

scholarly journals Kinetics of the Thermal Oxidation of Ir(100) toward IrO2 Studied by Ambient-Pressure X-ray Photoelectron Spectroscopy

2020 ◽  
Vol 11 (9) ◽  
pp. 3601-3607 ◽  
Author(s):  
Zbynek Novotny ◽  
Benjamin Tobler ◽  
Luca Artiglia ◽  
Martin Fischer ◽  
Matthias Schreck ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
X Ray ◽  
Kinetics Of

scholarly journals Self-Assembled Bimetallic Aluminum-Salen Catalyst for the Cyclic Carbonates Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4097
Author(s):  
Wooyong Seong ◽  
Hyungwoo Hahm ◽  
Seyong Kim ◽  
Jongwoo Park ◽  
Khalil A. Abboud ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Reaction Pathway ◽  
Kinetic Studies ◽  
Cyclic Carbonate ◽  
Reaction Conditions ◽  
Formation Reaction ◽  
X Ray ◽  
Carbonate Formation ◽  
Salen Aluminum

Bimetallic bis-urea functionalized salen-aluminum catalysts have been developed for cyclic carbonate synthesis from epoxides and CO2. The urea moiety provides a bimetallic scaffold through hydrogen bonding, which expedites the cyclic carbonate formation reaction under mild reaction conditions. The turnover frequency (TOF) of the bis-urea salen Al catalyst is three times higher than that of a μ-oxo-bridged catalyst, and 13 times higher than that of a monomeric salen aluminum catalyst. The bimetallic reaction pathway is suggested based on urea additive studies and kinetic studies. Additionally, the X-ray crystal structure of a bis-urea salen Ni complex supports the self-assembly of the bis-urea salen metal complex through hydrogen bonding.

scholarly journals In situ monitoring of the influence of water on DNA radiation damage by near-ambient pressure X-ray photoelectron spectroscopy

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Marc Benjamin Hahn ◽  
Paul M. Dietrich ◽  
Jörg Radnik
Keyword(s):  
Dna Damage ◽  
Radiation Damage ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
In Situ Monitoring ◽  
Strong Increase ◽  
Oh Radicals ◽  
Strand Breaks ◽  
X Ray

AbstractIonizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.

scholarly journals New ambient pressure X-ray photoelectron spectroscopy endstation at Taiwan light source

2019 ◽  
Author(s):  
Chia-Hsin Wang ◽  
Sun-Tang Chang ◽  
Sheng-Yuan Chen ◽  
Yaw-Wen Yang
Keyword(s):  
Light Source ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
X Ray

Ambient Pressure Hard X-ray Photoelectron Spectroscopy for Functional Material Systems as Fuel Cells under Working Conditions

2018 ◽  
Vol 51 (3) ◽  
pp. 719-727 ◽  
Author(s):  
Yasumasa Takagi ◽  
Tomoya Uruga ◽  
Mizuki Tada ◽  
Yasuhiro Iwasawa ◽  
Toshihiko Yokoyama
Keyword(s):  
Fuel Cells ◽  
Working Conditions ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Functional Material ◽  
X Ray ◽  
Material Systems
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