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Title: Multiple Non-Thermal Reaction Steps for the Photooxidation CO to CO2 on Reduced TiO2(110)

Abstract

The photooxidation of CO on reduced, rutile TiO2(110) was studied on a millisecond timescale. For a saturation coverage of chemisorbed O2 (0sat) and for half that coverage, the CO2 photon-stimulated desorption (PSD) signal is initially zero, increases to a maximum after several tens of milliseconds, and then decreases at longer times. The CO2 PSD signal increases ~5 times more quickly for 0.50sat. The initial rate of increase of the CO2 PSD signal is proportional to the flux of UV photons. The intermediate species involved in the reactions is stable for at least 100 s at 30 K. These results show that two or more non-thermal reaction steps are required to photooxidize CO adsorbed on TiO2(110). In contrast, previous models had suggested that CO photooxidation required only one non-thermal reaction. The likely initial and final charge states of the system suggest that an electron-mediated reaction and a hole-mediated reaction are needed for the complete photooxidation reaction.

Authors:
;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1073568
Report Number(s):
PNNL-SA-92421
47406; KC0301020
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
The Journal of Physical Chemistry Letters, 4(3):344-349
Additional Journal Information:
Journal Name: The Journal of Physical Chemistry Letters, 4(3):344-349
Country of Publication:
United States
Language:
English
Subject:
Environmental Molecular Sciences Laboratory

Citation Formats

Petrik, Nikolay G., and Kimmel, Gregory A. Multiple Non-Thermal Reaction Steps for the Photooxidation CO to CO2 on Reduced TiO2(110). United States: N. p., 2013. Web. doi:10.1021/jz302012j.
Petrik, Nikolay G., & Kimmel, Gregory A. Multiple Non-Thermal Reaction Steps for the Photooxidation CO to CO2 on Reduced TiO2(110). United States. https://doi.org/10.1021/jz302012j
Petrik, Nikolay G., and Kimmel, Gregory A. 2013. "Multiple Non-Thermal Reaction Steps for the Photooxidation CO to CO2 on Reduced TiO2(110)". United States. https://doi.org/10.1021/jz302012j.
@article{osti_1073568,
title = {Multiple Non-Thermal Reaction Steps for the Photooxidation CO to CO2 on Reduced TiO2(110)},
author = {Petrik, Nikolay G. and Kimmel, Gregory A.},
abstractNote = {The photooxidation of CO on reduced, rutile TiO2(110) was studied on a millisecond timescale. For a saturation coverage of chemisorbed O2 (0sat) and for half that coverage, the CO2 photon-stimulated desorption (PSD) signal is initially zero, increases to a maximum after several tens of milliseconds, and then decreases at longer times. The CO2 PSD signal increases ~5 times more quickly for 0.50sat. The initial rate of increase of the CO2 PSD signal is proportional to the flux of UV photons. The intermediate species involved in the reactions is stable for at least 100 s at 30 K. These results show that two or more non-thermal reaction steps are required to photooxidize CO adsorbed on TiO2(110). In contrast, previous models had suggested that CO photooxidation required only one non-thermal reaction. The likely initial and final charge states of the system suggest that an electron-mediated reaction and a hole-mediated reaction are needed for the complete photooxidation reaction.},
doi = {10.1021/jz302012j},
url = {https://www.osti.gov/biblio/1073568}, journal = {The Journal of Physical Chemistry Letters, 4(3):344-349},
number = ,
volume = ,
place = {United States},
year = {Thu Feb 07 00:00:00 EST 2013},
month = {Thu Feb 07 00:00:00 EST 2013}
}