Monitoring Chemical Reactions with Terahertz Rotational Spectroscopy

Dayne F. Swearer; Samuel Gottheim; Jay G. Simmons; Dane J. Phillips; Matthew J. Kale; Michael J. McClain; Phillip Christopher; Naomi J. Halas; Henry O. Everitt

doi:10.1021/acsphotonics.8b00342

Monitoring Chemical Reactions with Terahertz Rotational Spectroscopy

Dayne F. Swearer, Samuel Gottheim, Jay G. Simmons, Dane J. Phillips, Matthew J. Kale, Michael J. McClain, Phillip Christopher, Naomi J. Halas, Henry O. Everitt

Chemical Engineering and Materials Science

Research output: Contribution to journal › Article › peer-review

21 Scopus citations

Abstract

Rotational spectroscopy is introduced as a new in situ method for monitoring gas-phase reactants and products during chemical reactions. Exploiting its unambiguous molecular recognition specificity and extraordinary detection sensitivity, rotational spectroscopy at terahertz frequencies was used to monitor the decomposition of carbonyl sulfide (OCS) over an aluminum nanocrystal (AlNC) plasmonic photocatalyst. The intrinsic surface oxide on AlNCs is discovered to have a large number of strongly basic sites that are effective for mediating OCS decomposition. Spectroscopic monitoring revealed two different photothermal decomposition pathways for OCS, depending on the absence or presence of H₂O. The strength of rotational spectroscopy is witnessed through its ability to detect and distinguish isotopologues of the same mass from an unlabeled OCS precursor at concentrations of <1 nanomolar or partial pressures of <10 μTorr. These attributes recommend rotational spectroscopy as a compelling alternative for monitoring gas-phase chemical reactants and products in real time.

Original language	English (US)
Pages (from-to)	3097-3106
Number of pages	10
Journal	ACS Photonics
Volume	5
Issue number	8
DOIs	https://doi.org/10.1021/acsphotonics.8b00342
State	Published - Aug 15 2018

Bibliographical note

Funding Information:
The authors thank C. Neese and M. Reish for discussions regarding rotational spectroscopy, J. Yang, A. Alabastri, and P. Nordlander for discussions regarding photothermal heating of the Al NCs in vacuo, and Hossein Robatjazi for the instrument schematic in Figure 1a. This work was funded by the Air Force Office of Scientific Research Multidisciplinary Research Program of the University Research Initiative (AFOSR MURI FA9550-15-1-0022), the Army Research Office (MURI W911NF-12-1-0407), Defense Threat Reduction Agency (HDTRA 1-16-1-0042), the Army Aviation and Missile RD&E Center In-house Laboratory Innovative Research program, and the Welch Foundation under grant C-1220 (N.J.H.). D.F.S. acknowledges the National Science Foundation for a Graduate Research Fellowship under grant no. 1450681.

Publisher Copyright:
© 2018 American Chemical Society.

Keywords

aluminum nanocrystals
carbonyl sulfide
photocatalysis
plasmonics
rotational spectroscopy

Publisher link

10.1021/acsphotonics.8b00342

Find It

Find It at U of M Libraries

Cite this

@article{cd450ef0823542e280b476eb90b41924,

title = "Monitoring Chemical Reactions with Terahertz Rotational Spectroscopy",

abstract = "Rotational spectroscopy is introduced as a new in situ method for monitoring gas-phase reactants and products during chemical reactions. Exploiting its unambiguous molecular recognition specificity and extraordinary detection sensitivity, rotational spectroscopy at terahertz frequencies was used to monitor the decomposition of carbonyl sulfide (OCS) over an aluminum nanocrystal (AlNC) plasmonic photocatalyst. The intrinsic surface oxide on AlNCs is discovered to have a large number of strongly basic sites that are effective for mediating OCS decomposition. Spectroscopic monitoring revealed two different photothermal decomposition pathways for OCS, depending on the absence or presence of H2O. The strength of rotational spectroscopy is witnessed through its ability to detect and distinguish isotopologues of the same mass from an unlabeled OCS precursor at concentrations of <1 nanomolar or partial pressures of <10 μTorr. These attributes recommend rotational spectroscopy as a compelling alternative for monitoring gas-phase chemical reactants and products in real time.",

keywords = "aluminum nanocrystals, carbonyl sulfide, photocatalysis, plasmonics, rotational spectroscopy",

author = "Swearer, {Dayne F.} and Samuel Gottheim and Simmons, {Jay G.} and Phillips, {Dane J.} and Kale, {Matthew J.} and McClain, {Michael J.} and Phillip Christopher and Halas, {Naomi J.} and Everitt, {Henry O.}",

note = "Funding Information: The authors thank C. Neese and M. Reish for discussions regarding rotational spectroscopy, J. Yang, A. Alabastri, and P. Nordlander for discussions regarding photothermal heating of the Al NCs in vacuo, and Hossein Robatjazi for the instrument schematic in Figure 1a. This work was funded by the Air Force Office of Scientific Research Multidisciplinary Research Program of the University Research Initiative (AFOSR MURI FA9550-15-1-0022), the Army Research Office (MURI W911NF-12-1-0407), Defense Threat Reduction Agency (HDTRA 1-16-1-0042), the Army Aviation and Missile RD&E Center In-house Laboratory Innovative Research program, and the Welch Foundation under grant C-1220 (N.J.H.). D.F.S. acknowledges the National Science Foundation for a Graduate Research Fellowship under grant no. 1450681. Publisher Copyright: {\textcopyright} 2018 American Chemical Society.",

year = "2018",

month = aug,

day = "15",

doi = "10.1021/acsphotonics.8b00342",

language = "English (US)",

volume = "5",

pages = "3097--3106",

journal = "ACS Photonics",

issn = "2330-4022",

publisher = "American Chemical Society",

number = "8",

}

TY - JOUR

T1 - Monitoring Chemical Reactions with Terahertz Rotational Spectroscopy

AU - Swearer, Dayne F.

AU - Gottheim, Samuel

AU - Simmons, Jay G.

AU - Phillips, Dane J.

AU - Kale, Matthew J.

AU - McClain, Michael J.

AU - Christopher, Phillip

AU - Halas, Naomi J.

AU - Everitt, Henry O.

N1 - Funding Information: The authors thank C. Neese and M. Reish for discussions regarding rotational spectroscopy, J. Yang, A. Alabastri, and P. Nordlander for discussions regarding photothermal heating of the Al NCs in vacuo, and Hossein Robatjazi for the instrument schematic in Figure 1a. This work was funded by the Air Force Office of Scientific Research Multidisciplinary Research Program of the University Research Initiative (AFOSR MURI FA9550-15-1-0022), the Army Research Office (MURI W911NF-12-1-0407), Defense Threat Reduction Agency (HDTRA 1-16-1-0042), the Army Aviation and Missile RD&E Center In-house Laboratory Innovative Research program, and the Welch Foundation under grant C-1220 (N.J.H.). D.F.S. acknowledges the National Science Foundation for a Graduate Research Fellowship under grant no. 1450681. Publisher Copyright: © 2018 American Chemical Society.

PY - 2018/8/15

Y1 - 2018/8/15

N2 - Rotational spectroscopy is introduced as a new in situ method for monitoring gas-phase reactants and products during chemical reactions. Exploiting its unambiguous molecular recognition specificity and extraordinary detection sensitivity, rotational spectroscopy at terahertz frequencies was used to monitor the decomposition of carbonyl sulfide (OCS) over an aluminum nanocrystal (AlNC) plasmonic photocatalyst. The intrinsic surface oxide on AlNCs is discovered to have a large number of strongly basic sites that are effective for mediating OCS decomposition. Spectroscopic monitoring revealed two different photothermal decomposition pathways for OCS, depending on the absence or presence of H2O. The strength of rotational spectroscopy is witnessed through its ability to detect and distinguish isotopologues of the same mass from an unlabeled OCS precursor at concentrations of <1 nanomolar or partial pressures of <10 μTorr. These attributes recommend rotational spectroscopy as a compelling alternative for monitoring gas-phase chemical reactants and products in real time.

AB - Rotational spectroscopy is introduced as a new in situ method for monitoring gas-phase reactants and products during chemical reactions. Exploiting its unambiguous molecular recognition specificity and extraordinary detection sensitivity, rotational spectroscopy at terahertz frequencies was used to monitor the decomposition of carbonyl sulfide (OCS) over an aluminum nanocrystal (AlNC) plasmonic photocatalyst. The intrinsic surface oxide on AlNCs is discovered to have a large number of strongly basic sites that are effective for mediating OCS decomposition. Spectroscopic monitoring revealed two different photothermal decomposition pathways for OCS, depending on the absence or presence of H2O. The strength of rotational spectroscopy is witnessed through its ability to detect and distinguish isotopologues of the same mass from an unlabeled OCS precursor at concentrations of <1 nanomolar or partial pressures of <10 μTorr. These attributes recommend rotational spectroscopy as a compelling alternative for monitoring gas-phase chemical reactants and products in real time.

KW - aluminum nanocrystals

KW - carbonyl sulfide

KW - photocatalysis

KW - plasmonics

KW - rotational spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=85047400475&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85047400475&partnerID=8YFLogxK

U2 - 10.1021/acsphotonics.8b00342

DO - 10.1021/acsphotonics.8b00342

M3 - Article

AN - SCOPUS:85047400475

SN - 2330-4022

VL - 5

SP - 3097

EP - 3106

JO - ACS Photonics

JF - ACS Photonics

IS - 8

ER -

Monitoring Chemical Reactions with Terahertz Rotational Spectroscopy

Abstract

Bibliographical note

Keywords

Publisher link

Find It

Other files and links

Fingerprint

Cite this