Visualization of gas distribution in a model AP-XPS reactor by PLIF : Co oxidation over a Pd(100) catalyst

Summary, in English

In situ knowledge of the gas phase around a catalyst is essential to make an accurate correlation between the catalytic activity and surface structure in operando studies. Although ambient pressure X-ray photoelectron spectroscopy (AP-XPS) can provide information on the gas phase as well as the surface structure of a working catalyst, the gas phase detected has not been spatially resolved to date, thus possibly making it ambiguous to interpret the AP-XPS spectra. In this work, planar laser-induced fluorescence (PLIF) is used to visualize the CO₂ distribution in a model AP-XPS reactor, during CO oxidation over a Pd(100) catalyst. The results show that the gas composition in the vicinity of the sample measured by PLIF is significantly different from that measured by a conventional mass spectrometer connected to a nozzle positioned just above the sample. In addition, the gas distribution above the catalytic sample has a strong dependence on the gas flow and total chamber pressure. The technique presented has the potential to increase our knowledge of the gas phase in AP-XPS, as well as to optimize the design and operating conditions of in situ AP-XPS reactors for catalysis studies.

• Author: Jianfeng Zhou; Sara Blomberg; Johan Gustafson; Edvin Lundgren; Johan Zetterberg
• Department/s: Combustion Physics; Synchrotron Radiation Research
• Publishing year: 2017-01-17
• Language: English
• Publication/Series: Catalysts
• Volume: 7
• Issue: 1
• Links: http://dx.doi.org/10.3390/catal7010029
• Document type: Journal article
• Publisher: MDPI AG
• Topic: Physical Sciences; Atom and Molecular Physics and Optics; Condensed Matter Physics (including Material Physics, Nano Physics)
• Keywords: AP-XPS; Boundary layer; CO oxidation; PLIF
• Status: Published
• ISBN/ISSN/Other: ISSN: 2073-4344