Quantitative and Sensitive Mid-Infrared Frequency Modulation Detection of HCN behind Shock Waves
Despite its key role for the study and modeling of nitrogen chemistry and NO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi mathvariant="normal">x</mi><...
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MDPI AG
2021-10-01
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| Online Access: | https://www.mdpi.com/2673-3994/2/4/25 |
| _version_ | 1797504520349024256 |
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| author | Michael Stuhr Sebastian Hesse Gernot Friedrichs |
| author_facet | Michael Stuhr Sebastian Hesse Gernot Friedrichs |
| author_sort | Michael Stuhr |
| collection | DOAJ |
| description | Despite its key role for the study and modeling of nitrogen chemistry and NO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi mathvariant="normal">x</mi></msub></semantics></math></inline-formula> formation in combustion processes, HCN has only rarely been detected under high-temperature conditions. Here, we demonstrate quantitative detection of HCN behind incident and reflected shock waves using a novel sensitive single-tone mid-infrared frequency modulation (mid-IR-FM) detection scheme. The temperature-dependent pressure broadening of the P(26) line in the fundamental CH stretch vibration band was investigated in the temperature range <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>670</mn><mspace width="3.33333pt"></mspace><mi mathvariant="normal">K</mi><mo>≤</mo><mi>T</mi><mo>≤</mo><mn>1460</mn><mspace width="3.33333pt"></mspace><mi mathvariant="normal">K</mi></mrow></semantics></math></inline-formula>, yielding a pressure broadening coefficient for argon of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2</mn><msubsup><mi>γ</mi><mrow><mi>Ar</mi></mrow><mrow><mn>296</mn><mspace width="4.pt"></mspace><mi mathvariant="normal">K</mi></mrow></msubsup><mo>=</mo><mrow><mo>(</mo><mn>0.093</mn><mo>±</mo><mn>0.007</mn><mo>)</mo></mrow><mspace width="3.33333pt"></mspace><msup><mi>cm</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup><msup><mi>atm</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> and a temperature exponent of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>n</mi><mi>Ar</mi></msub><mo>=</mo><mn>0.67</mn><mo>±</mo><mn>0.07</mn></mrow></semantics></math></inline-formula>. The sensitivity of the detection scheme was characterized by means of an Allan analysis, showing that HCN detection on the ppm mixing ratio level is possible at typical shock wave conditions. In order to demonstrate the capability of mid-IR-FM spectroscopy for future high-temperature reaction kinetic studies, we also report the first successful measurement of a reactive HCN decay profile induced by its reaction with oxygen atoms. |
| first_indexed | 2024-03-10T04:05:45Z |
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| institution | Directory Open Access Journal |
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| language | English |
| last_indexed | 2024-03-10T04:05:45Z |
| publishDate | 2021-10-01 |
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| spelling | doaj.art-dcc34f7e715245948ac0a7bedd181bdb2023-11-23T08:24:52ZengMDPI AGFuels2673-39942021-10-012443744710.3390/fuels2040025Quantitative and Sensitive Mid-Infrared Frequency Modulation Detection of HCN behind Shock WavesMichael Stuhr0Sebastian Hesse1Gernot Friedrichs2Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 1, 24118 Kiel, GermanyInstitut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 1, 24118 Kiel, GermanyInstitut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 1, 24118 Kiel, GermanyDespite its key role for the study and modeling of nitrogen chemistry and NO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi mathvariant="normal">x</mi></msub></semantics></math></inline-formula> formation in combustion processes, HCN has only rarely been detected under high-temperature conditions. Here, we demonstrate quantitative detection of HCN behind incident and reflected shock waves using a novel sensitive single-tone mid-infrared frequency modulation (mid-IR-FM) detection scheme. The temperature-dependent pressure broadening of the P(26) line in the fundamental CH stretch vibration band was investigated in the temperature range <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>670</mn><mspace width="3.33333pt"></mspace><mi mathvariant="normal">K</mi><mo>≤</mo><mi>T</mi><mo>≤</mo><mn>1460</mn><mspace width="3.33333pt"></mspace><mi mathvariant="normal">K</mi></mrow></semantics></math></inline-formula>, yielding a pressure broadening coefficient for argon of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2</mn><msubsup><mi>γ</mi><mrow><mi>Ar</mi></mrow><mrow><mn>296</mn><mspace width="4.pt"></mspace><mi mathvariant="normal">K</mi></mrow></msubsup><mo>=</mo><mrow><mo>(</mo><mn>0.093</mn><mo>±</mo><mn>0.007</mn><mo>)</mo></mrow><mspace width="3.33333pt"></mspace><msup><mi>cm</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup><msup><mi>atm</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> and a temperature exponent of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>n</mi><mi>Ar</mi></msub><mo>=</mo><mn>0.67</mn><mo>±</mo><mn>0.07</mn></mrow></semantics></math></inline-formula>. The sensitivity of the detection scheme was characterized by means of an Allan analysis, showing that HCN detection on the ppm mixing ratio level is possible at typical shock wave conditions. In order to demonstrate the capability of mid-IR-FM spectroscopy for future high-temperature reaction kinetic studies, we also report the first successful measurement of a reactive HCN decay profile induced by its reaction with oxygen atoms.https://www.mdpi.com/2673-3994/2/4/25mid-infrared frequency modulation spectroscopyshock wavescombustion diagnosticshigh-temperature detectionhydrogen cyanidepressure broadening |
| spellingShingle | Michael Stuhr Sebastian Hesse Gernot Friedrichs Quantitative and Sensitive Mid-Infrared Frequency Modulation Detection of HCN behind Shock Waves Fuels mid-infrared frequency modulation spectroscopy shock waves combustion diagnostics high-temperature detection hydrogen cyanide pressure broadening |
| title | Quantitative and Sensitive Mid-Infrared Frequency Modulation Detection of HCN behind Shock Waves |
| title_full | Quantitative and Sensitive Mid-Infrared Frequency Modulation Detection of HCN behind Shock Waves |
| title_fullStr | Quantitative and Sensitive Mid-Infrared Frequency Modulation Detection of HCN behind Shock Waves |
| title_full_unstemmed | Quantitative and Sensitive Mid-Infrared Frequency Modulation Detection of HCN behind Shock Waves |
| title_short | Quantitative and Sensitive Mid-Infrared Frequency Modulation Detection of HCN behind Shock Waves |
| title_sort | quantitative and sensitive mid infrared frequency modulation detection of hcn behind shock waves |
| topic | mid-infrared frequency modulation spectroscopy shock waves combustion diagnostics high-temperature detection hydrogen cyanide pressure broadening |
| url | https://www.mdpi.com/2673-3994/2/4/25 |
| work_keys_str_mv | AT michaelstuhr quantitativeandsensitivemidinfraredfrequencymodulationdetectionofhcnbehindshockwaves AT sebastianhesse quantitativeandsensitivemidinfraredfrequencymodulationdetectionofhcnbehindshockwaves AT gernotfriedrichs quantitativeandsensitivemidinfraredfrequencymodulationdetectionofhcnbehindshockwaves |