1 research outputs found
Tabletop Femtosecond VUV Photoionization and PEPICO Detection of Microreactor Pyrolysis Products
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 the ability to distinguish thermal products from dissociative
ionization. Here, vacuum ultraviolet light is derived 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 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 illustrates the
advantages and potential of this approach