Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

Journal Article · Thu May 15 04:00:00 EDT 2014 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4874002· OSTI ID:22254894

Mayr, Lukas; Klötzer, Bernhard; Penner, Simon ^[1]; Rameshan, Raffael ^[1]; Rameshan, Christoph ^[1]

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1. Institute of Physical Chemistry, University of Innsbruck, Innrain 52a, 6020 Innsbruck (Austria)

An ultra-high vacuum (UHV) setup for “real” and “inverse” model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, “magic angle”) and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown.

• OSTI ID: 22254894
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 5 Vol. 85; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
AUGER ELECTRON SPECTROSCOPY
CATALYSIS
CATALYSTS
DESIGN
ELECTRON BEAMS
EVAPORATORS
METHANOL
MICROBALANCES
PUMPS
QUARTZ
REACTION KINETICS
SAMPLE HOLDERS
SAMPLE PREPARATION
THICKNESS
X RADIATION
X-RAY PHOTOELECTRON SPECTROSCOPY