Tabletop Femtosecond VUV Photoionization and PEPICO Detection of Microreactor Pyrolysis Products

Journal Article · Thu Jun 29 00:00:00 EDT 2017 · Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory

DOI: https://doi.org/10.1021/acs.jpca.7b02821 · OSTI ID:1372114

Couch, David E.  ^[1]; Buckingham, Grant T. ^[2]; Baraban, Joshua H. ^[2]; Porterfield, Jessica P. ^[2]; Wooldridge, Laura A. ^[3]; Ellison, G. Barney  ^[2]; Kapteyn, Henry C. ^[3]; Murnane, Margaret M. ^[3]; Peters, William K.  ^[3]

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1. Univ. of Colorado, Boulder, CO (United States). JILA and Dept. of Physics; University of Colorado
2. Univ. of Colorado, Boulder, CO (United States). Dept. of Chemistry
3. Univ. of Colorado, Boulder, CO (United States). JILA and Dept. of Physics

Here, we report the combination of tabletop vacuum ultraviolet photoionization with photoion--photoelectron coincidence spectroscopy for sensitive, isomer-specific detection of nascent products from a pyrolysis microreactor. Results on several molecules demonstrate two essential capabilities that are very straightforward to implement: the ability to differentiate isomers, and to distinguish thermal products from dissociative ionization. We derive vacuum ultraviolet light is from a commercial tabletop femtosecond laser system, allowing data to be collected at 10 kHz; this high repetition rate is critical for coincidence techniques. The photoion—photoelectron coincidence spectrometer uses the momentum of the ion to identify dissociative ionization events, and coincidence techniques to provide a photoelectron spectrum specific to each mass, which is used to distinguish different isomers. We also have used this spectrometer to detect the pyrolysis products that result from the thermal cracking of acetaldehyde, cyclohexene, and 2-butanol. The photoion—photoelectron spectrometer can detect and identify organic radicals and reactive intermediates that result from pyrolysis. Direct comparison of laboratory and synchrotron data illustrate the advantages and potential of this approach.

• Research Organization: Univ. of Colorado, Boulder, CO (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: FG02-99ER14982; AC02-05CH11231
• OSTI ID: 1372114
• Journal Information: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory, Journal Name: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory Journal Issue: 28 Vol. 121; ISSN 1089-5639
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English