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Title: Pyrolysis of the Simplest Carbohydrate, Glycolaldehyde (CHO-CH 2OH), and Glyoxal in a Heated Microreactor

Both glycolaldehyde and glyoxal were pyrolyzed in a set of flash-pyrolysis microreactors. The pyrolysis products resulting from CHO-CH 2OH and HCO-CHO were detected and identified by vacuum ultraviolet (VUV) photoionization mass spectrometry. Complementary product identification was provided by argon matrix infrared absorption spectroscopy. Pyrolysis pressures in the microreactor were about 100 Torr, and contact times with the microreactors were roughly 100 μs. At 1200 K, the products of glycolaldehyde pyrolysis are H atoms, CO, CH 2=O, CH 2=C=O, and HCO-CHO. Thermal decomposition of HCO-CHO was studied with pulsed 118.2 nm photoionization mass spectrometry and matrix infrared absorption. Under these conditions, glyoxal undergoes pyrolysis to H atoms and CO. Tunable VUV photoionization mass spectrometry provides a lower bound for the ionization energy IE(CHO-CH 2OH) ≥ 9.95 ± 0.05 eV. The gas-phase heat of formation of glycolaldehyde was established by a sequence of calorimetric experiments. The experimental result is Δ fH 298(CHO-CH 2OH) = -75.8 ± 1.3 kcal mol -1. Fully ab initio, coupled cluster calculations predict Δ fH 0(CHO-CH 2OH) of -73.1 ± 0.5 kcal mol -1 and Δ fH 298(CHO-CH 2OH) of -76.1 ± 0.5 kcal mol -1. The coupled-cluster singles doubles and noniterative triples correction calculations also lead tomore » a revision of the geometry of CHO-CH 2OH. We have found that the O-H bond length differs substantially from earlier experimental estimates, due to unusual zero-point contributions to the moments of inertia.« less
Authors:
 [1] ;  [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [6] ;  [1]
  1. Univ. of Colorado, Boulder, CO (United States). Dept. of Chemistry and Biochemistry
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Chemical Sciences Division
  3. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
  4. Xavier Univ. of Louisiana, New Orleans, LA (United States). Dept. of Chemistry
  5. Univ. of Colorado, Boulder, CO (United States). Center for Combustion and Environmental Research and Dept. of Mechanical Engineering,
  6. Univ. of Texas, Austin, TX (United States). Dept. of Chemistry
Publication Date:
Grant/Contract Number:
AC02-05CH11231; CBET-1403979; CHE-1361874; CHE-1361031; F-1283; FG02-07ER15884
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
Additional Journal Information:
Journal Volume: 120; Journal Issue: 14; Related Information: © 2016 American Chemical Society.; Journal ID: ISSN 1089-5639
Publisher:
American Chemical Society
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division; National Science Foundation (NSF); Univ. of New Orleans, New Orleans, LA (United States). Advanced Materials Research Inst. (AMRI) Fabrication, Analysis, and Consulting Services (FACS); Robert A. Welch Foundation
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 47 OTHER INSTRUMENTATION
OSTI Identifier:
1464135

Porterfield, Jessica P., Baraban, Joshua H., Troy, Tyler P., Ahmed, Musahid, McCarthy, Michael C., Morgan, Kathleen M., Daily, John W., Nguyen, Thanh Lam, Stanton, John F., and Ellison, G. Barney. Pyrolysis of the Simplest Carbohydrate, Glycolaldehyde (CHO-CH2OH), and Glyoxal in a Heated Microreactor. United States: N. p., Web. doi:10.1021/acs.jpca.6b00652.
Porterfield, Jessica P., Baraban, Joshua H., Troy, Tyler P., Ahmed, Musahid, McCarthy, Michael C., Morgan, Kathleen M., Daily, John W., Nguyen, Thanh Lam, Stanton, John F., & Ellison, G. Barney. Pyrolysis of the Simplest Carbohydrate, Glycolaldehyde (CHO-CH2OH), and Glyoxal in a Heated Microreactor. United States. doi:10.1021/acs.jpca.6b00652.
Porterfield, Jessica P., Baraban, Joshua H., Troy, Tyler P., Ahmed, Musahid, McCarthy, Michael C., Morgan, Kathleen M., Daily, John W., Nguyen, Thanh Lam, Stanton, John F., and Ellison, G. Barney. 2016. "Pyrolysis of the Simplest Carbohydrate, Glycolaldehyde (CHO-CH2OH), and Glyoxal in a Heated Microreactor". United States. doi:10.1021/acs.jpca.6b00652. https://www.osti.gov/servlets/purl/1464135.
@article{osti_1464135,
title = {Pyrolysis of the Simplest Carbohydrate, Glycolaldehyde (CHO-CH2OH), and Glyoxal in a Heated Microreactor},
author = {Porterfield, Jessica P. and Baraban, Joshua H. and Troy, Tyler P. and Ahmed, Musahid and McCarthy, Michael C. and Morgan, Kathleen M. and Daily, John W. and Nguyen, Thanh Lam and Stanton, John F. and Ellison, G. Barney},
abstractNote = {Both glycolaldehyde and glyoxal were pyrolyzed in a set of flash-pyrolysis microreactors. The pyrolysis products resulting from CHO-CH2OH and HCO-CHO were detected and identified by vacuum ultraviolet (VUV) photoionization mass spectrometry. Complementary product identification was provided by argon matrix infrared absorption spectroscopy. Pyrolysis pressures in the microreactor were about 100 Torr, and contact times with the microreactors were roughly 100 μs. At 1200 K, the products of glycolaldehyde pyrolysis are H atoms, CO, CH2=O, CH2=C=O, and HCO-CHO. Thermal decomposition of HCO-CHO was studied with pulsed 118.2 nm photoionization mass spectrometry and matrix infrared absorption. Under these conditions, glyoxal undergoes pyrolysis to H atoms and CO. Tunable VUV photoionization mass spectrometry provides a lower bound for the ionization energy IE(CHO-CH2OH) ≥ 9.95 ± 0.05 eV. The gas-phase heat of formation of glycolaldehyde was established by a sequence of calorimetric experiments. The experimental result is ΔfH298(CHO-CH2OH) = -75.8 ± 1.3 kcal mol-1. Fully ab initio, coupled cluster calculations predict ΔfH0(CHO-CH2OH) of -73.1 ± 0.5 kcal mol-1 and ΔfH298(CHO-CH2OH) of -76.1 ± 0.5 kcal mol-1. The coupled-cluster singles doubles and noniterative triples correction calculations also lead to a revision of the geometry of CHO-CH2OH. We have found that the O-H bond length differs substantially from earlier experimental estimates, due to unusual zero-point contributions to the moments of inertia.},
doi = {10.1021/acs.jpca.6b00652},
journal = {Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory},
number = 14,
volume = 120,
place = {United States},
year = {2016},
month = {3}
}