Demonstration Of Cresu-rempi For Reaction Kinetic Measurements In The Gas-phase

Gurusinghe, Ranil

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https://hdl.handle.net/2142/116743 Copy

Description

Title

Demonstration Of Cresu-rempi For Reaction Kinetic Measurements In The Gas-phase

Author(s)

Gurusinghe, Ranil

Contributor(s)

• Suits, Arthur
• Edlin, Matthew L.
• Lang, Jinxin
• Dias, Nureshan

Issue Date

2022-06-22

Keyword(s)

Instrument/Technique Demonstration

Abstract

The CRESU technique (French acronym for “reaction kinetics in uniform supersonic flows”) provides a wall-less gas-phase reactor to measure low-temperature reaction kinetics. In the past, probing methods such as laser-induced fluorescence (LIF), mass spectrometry, and chirped-pulse uniform flow (CPUF) microwave spectroscopy have been successfully used to measures reaction kinetics in CRESU flows, but the latter two call for sampling of the flow prior to detection. Here we show a selective, low-cost, and highly sensitive probing tool to measure the kinetics of reactions that involve both molecular and atomic species. This new detection method uses resonance-enhance multi-photon ionization (REMPI) and an electron capture probe, adapted from approaches successfully used in flames, to selectively identify atomic and molecular species. A negative-biased high voltage applied to two electrodes, that are placed on either side of a grounded probe, enables rapid capture of electrons produced by the selective ionization from the REMPI spectroscopy. The performance of this setup was verified by recording the (1+1) REMPI spectra of nitric oxide in 20 K and 50 K uniform supersonic flows. The REMPI probe response is proportional to the number of electrons produced by ionization, and therefore to the concentration of ionized species. Thus, the time-dependent REMPI signal can be used to measure the rate of decay or growth of a reactant or product in fast chemical reactions in CRESU flows.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116743

DOI

https://doi.org/10.15278/isms.2022.WJ04

Copyright and License Information

Copyright 2022 held by the authors

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