Surface oxidation-induced restructuring of liquid Pd-Ga SCALMS model catalysts

2021 ◽  
Author(s):  
Haiko Wittkaemper ◽  
Sven Maisel ◽  
Michael Moritz ◽  
Mathias Grabau ◽  
Andreas Görling ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Surface Oxidation ◽  
Model Catalysts ◽  
Model Systems ◽  
X Ray ◽  
Catalytically Active ◽  
Active Liquid

We have examined model systems for the recently reported Pd-Ga Supported Catalytically Active Liquid Metal Solutions (SCALMS) catalysts using near-ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) under oxidizing conditions. Gallium is...

scholarly journals Nanostructured, mesoporous Au/TiO2 model catalysts – structure, stability and catalytic properties

2011 ◽  
Vol 2 ◽  
pp. 593-606 ◽  
Author(s):  
Matthias Roos ◽  
Dominique Böcking ◽  
Kwabena Offeh Gyimah ◽  
Gabriela Kucerova ◽  
Joachim Bansmann ◽  
...  
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Model Catalysts ◽  
Model Systems ◽  
Structure Stability ◽  
Titanium Tetraisopropoxide ◽  
X Ray ◽  
Film Model ◽  
Thin Film Model

Aiming at model systems with close-to-realistic transport properties, we have prepared and studied planar Au/TiO2 thin-film model catalysts consisting of a thin mesoporous TiO2 film of 200–400 nm thickness with Au nanoparticles, with a mean particle size of ~2 nm diameter, homogeneously distributed therein. The systems were prepared by spin-coating of a mesoporous TiO2 film from solutions of ethanolic titanium tetraisopropoxide and Pluronic P123 on planar Si(100) substrates, calcination at 350 °C and subsequent Au loading by a deposition–precipitation procedure, followed by a final calcination step for catalyst activation. The structural and chemical properties of these model systems were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption, inductively coupled plasma ionization spectroscopy (ICP–OES) and X-ray photoelectron spectroscopy (XPS). The catalytic properties were evaluated through the oxidation of CO as a test reaction, and reactivities were measured directly above the film with a scanning mass spectrometer. We can demonstrate that the thin-film model catalysts closely resemble dispersed Au/TiO2 supported catalysts in their characteristic structural and catalytic properties, and hence can be considered as suitable for catalytic model studies. The linear increase of the catalytic activity with film thickness indicates that transport limitations inside the Au/TiO2 film catalyst are negligible, i.e., below the detection limit.

scholarly journals Surface Chemistry of Carbon Dioxide on Copper Model Catalysts Studied by Ambient-Pressure X-ray Photoelectron Spectroscopy

2019 ◽  
Vol 17 (0) ◽  
pp. 169-178 ◽  
Author(s):  
Takanori Koitaya ◽  
Susumu Yamamoto ◽  
Iwao Matsuda ◽  
Jun Yoshinobu
Keyword(s):  
Carbon Dioxide ◽  
Surface Chemistry ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Model Catalysts ◽  
X Ray

scholarly journals Organometallic Ruthenium Nanoparticles as Model Catalysts for CO Hydrogenation: A Nuclear Magnetic Resonance and Ambient-Pressure X-ray Photoelectron Spectroscopy Study

ACS Catalysis ◽  
2014 ◽  
Vol 4 (9) ◽  
pp. 3160-3168 ◽  
Author(s):  
Luis M. Martínez-Prieto ◽  
Sophie Carenco ◽  
Cheng H. Wu ◽  
Eric Bonnefille ◽  
Stephanus Axnanda ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Photoelectron Spectroscopy ◽  
Co Hydrogenation ◽  
Ambient Pressure ◽  
Model Catalysts ◽  
Spectroscopy Study ◽  
Ruthenium Nanoparticles ◽  
X Ray ◽  
Nuclear Magnetic

scholarly journals Novel Sample-Stage for Combined Near Ambient Pressure X-ray Photoelectron Spectroscopy, Catalytic Characterization and Electrochemical Impedance Spectroscopy

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 947
Author(s):  
Raffael Rameshan ◽  
Andreas Nenning ◽  
Johannes Raschhofer ◽  
Lorenz Lindenthal ◽  
Thomas Ruh ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Ambient Pressure ◽  
Rapid Development ◽  
Model Systems ◽  
X Ray ◽  
Precise Control ◽  
Lower Temperature

For an in-depth characterization of catalytic materials and their properties, spectroscopic in-situ (operando) investigations are indispensable. With the rapid development of advanced commercial spectroscopic equipment, it is possible to combine complementary methods in a single system. This allows for simultaneously gaining insights into surface and bulk properties of functional oxides, such as defect chemistry, catalytic characteristics, electronic structure, etc., enabling a direct correlation of structure and reactivity of catalyst materials, thus facilitating effective catalyst development. Here, we present a novel sample-stage, which was specifically developed to pave the way to a lab–based combination of near ambient pressure X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy with simultaneous catalytic operando measurements. This setup is designed to probe different (model) systems under conditions close to real heterogeneous catalysis, with a focus on solid oxide electrochemical cells. In a proof of concept experiment using an electrochemical model cell with the doped perovskite Nd0.6Ca0.4Fe0.9Co0.1O3-δ as working electrode, the precise control of the surface chemistry that is possible with this setup is demonstrated. The exsolution behavior of the material was studied, showing that at a lower temperature (500 °C) with lower reducing potential of the gas phase, only cobalt was exsolved, forming metallic particles on the surface of the perovskite-type oxide. Only when the temperature was increased to 600 °C and a cathodic potential was applied (−250 mV) Fe also started to be released from the perovskite lattice.

Introducing Time Resolution to Detect Ce3+ Catalytically Active Sites at the Pt/CeO2 Interface through Ambient Pressure X-ray Photoelectron Spectroscopy

2016 ◽  
Vol 8 (1) ◽  
pp. 102-108 ◽  
Author(s):  
Luca Artiglia ◽  
Fabrizio Orlando ◽  
Kanak Roy ◽  
René Kopelent ◽  
Olga Safonova ◽  
...  
Keyword(s):  
Time Resolution ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Ambient Pressure ◽  
X Ray ◽  
Catalytically Active

scholarly journals Non-Thermal Plasma-Modified Ru-Sn-Ti Catalyst for Chlorinated Volatile Organic Compound Degradation

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1456
Author(s):  
Yujie Fu ◽  
You Zhang ◽  
Qi Xin ◽  
Zhong Zheng ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Photoelectron Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Surface Oxidation ◽  
Treatment Method ◽  
X Ray ◽  
Chlorinated Volatile Organic Compounds ◽  
Volatile Organic ◽  
Doped Titania

Chlorinated volatile organic compounds (CVOCs) are vital environmental concerns due to their low biodegradability and long-term persistence. Catalytic combustion technology is one of the more commonly used technologies for the treatment of CVOCs. Catalysts with high low-temperature activity, superior selectivity of non-toxic products, and resistance to chlorine poisoning are desirable. Here we adopted a plasma treatment method to synthesize a tin-doped titania loaded with ruthenium dioxide (RuO2) catalyst, possessing enhanced activity (T90%, the temperature at which 90% of dichloromethane (DCM) is decomposed, is 262 °C) compared to the catalyst prepared by the conventional calcination method. As revealed by transmission electron microscopy, X-ray diffraction, N2 adsorption, X-ray photoelectron spectroscopy, and hydrogen temperature-programmed reduction, the high surface area of the tin-doped titania catalyst and the enhanced dispersion and surface oxidation of RuO2 induced by plasma treatment were found to be the main factors determining excellent catalytic activities.

Electrochemical reduction of CO2 in ionic liquid: Mechanistic study of Li–CO2 batteries via in situ ambient pressure X-ray photoelectron spectroscopy

Nano Energy ◽  
2021 ◽  
Vol 83 ◽  
pp. 105830
Author(s):  
Yu Wang ◽  
Wanwan Wang ◽  
Jing Xie ◽  
Chia-Hsin Wang ◽  
Yaw-Wen Yang ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Electrochemical Reduction ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Mechanistic Study ◽  
X Ray ◽  
Reduction Of Co2

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
Sign in / Sign up

Export Citation Format

Share Document