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Title: Interaction of Formaldehyde with the Rutile TiO 2 (110) Surface: A Combined Experimental and Theoretical Study

Abstract

The adsorption and reaction of formaldehyde (CH 2O) on the oxidized rutile TiO 2(110) surface were studied by temperature programmed desorption (TPD), scanning tunneling microscopy (STM), infrared reflection-absorption spectroscopy (IRRAS) and density functional theory (DFT) calculations. The experimental and theoretical data reveal the presence of various species depending on the temperature and coverage. After formaldehyde adsorption on TiO 2(110) at 65 K, the multilayer CH 2O was detected, which desorbs completely upon heating to 120 K. The isolated CH 2O monomer was identified after submonolayer adsorption at low temperatures (45-65 K), in which CH 2O is bound to the surface Ti5c sites via σ-donation and adopts a tilted geometry. With heating to higher temperatures the CH 2O monomers remain stable up to 70 K and then undergo coupling reactions to form paraformaldehyde (polyoxymethylene, POM) at the Ti 5c rows. The POM chain is oriented primarily along the [001] direction in a slightly disordered configuration. POM becomes the predominant species at 120 K and is decomposed releasing CH 2O at about 250 K. In addition, dioxymethylene (DOM) was detected as minority species formed via reaction of Ti 5c-bound CH 2O with both neighboring O 2c along the [1-10] direction and oxygenmore » adatoms (Oad) at Ti 5c sites along [001] on the oxidized TiO 2(110) surface.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1324912
Report Number(s):
PNNL-SA-116863
Journal ID: ISSN 1932-7447; 48287; 48368; KC0302010
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry. C; Journal Volume: 120; Journal Issue: 23
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Environmental Molecular Sciences Laboratory

Citation Formats

Yu, Xiaojuan, Zhang, Zhenrong, Yang, Chengwu, Bebensee, Fabian, Heissler, Stefan, Nefedov, Alexei, Tang, Miru, Ge, Qingfeng, Chen, Long, Kay, Bruce D., Dohnálek, Zdenek, Wang, Yuemin, and Wöll, Christof. Interaction of Formaldehyde with the Rutile TiO 2 (110) Surface: A Combined Experimental and Theoretical Study. United States: N. p., 2016. Web. doi:10.1021/acs.jpcc.6b03689.
Yu, Xiaojuan, Zhang, Zhenrong, Yang, Chengwu, Bebensee, Fabian, Heissler, Stefan, Nefedov, Alexei, Tang, Miru, Ge, Qingfeng, Chen, Long, Kay, Bruce D., Dohnálek, Zdenek, Wang, Yuemin, & Wöll, Christof. Interaction of Formaldehyde with the Rutile TiO 2 (110) Surface: A Combined Experimental and Theoretical Study. United States. doi:10.1021/acs.jpcc.6b03689.
Yu, Xiaojuan, Zhang, Zhenrong, Yang, Chengwu, Bebensee, Fabian, Heissler, Stefan, Nefedov, Alexei, Tang, Miru, Ge, Qingfeng, Chen, Long, Kay, Bruce D., Dohnálek, Zdenek, Wang, Yuemin, and Wöll, Christof. 2016. "Interaction of Formaldehyde with the Rutile TiO 2 (110) Surface: A Combined Experimental and Theoretical Study". United States. doi:10.1021/acs.jpcc.6b03689.
@article{osti_1324912,
title = {Interaction of Formaldehyde with the Rutile TiO 2 (110) Surface: A Combined Experimental and Theoretical Study},
author = {Yu, Xiaojuan and Zhang, Zhenrong and Yang, Chengwu and Bebensee, Fabian and Heissler, Stefan and Nefedov, Alexei and Tang, Miru and Ge, Qingfeng and Chen, Long and Kay, Bruce D. and Dohnálek, Zdenek and Wang, Yuemin and Wöll, Christof},
abstractNote = {The adsorption and reaction of formaldehyde (CH2O) on the oxidized rutile TiO2(110) surface were studied by temperature programmed desorption (TPD), scanning tunneling microscopy (STM), infrared reflection-absorption spectroscopy (IRRAS) and density functional theory (DFT) calculations. The experimental and theoretical data reveal the presence of various species depending on the temperature and coverage. After formaldehyde adsorption on TiO2(110) at 65 K, the multilayer CH2O was detected, which desorbs completely upon heating to 120 K. The isolated CH2O monomer was identified after submonolayer adsorption at low temperatures (45-65 K), in which CH2O is bound to the surface Ti5c sites via σ-donation and adopts a tilted geometry. With heating to higher temperatures the CH2O monomers remain stable up to 70 K and then undergo coupling reactions to form paraformaldehyde (polyoxymethylene, POM) at the Ti5c rows. The POM chain is oriented primarily along the [001] direction in a slightly disordered configuration. POM becomes the predominant species at 120 K and is decomposed releasing CH2O at about 250 K. In addition, dioxymethylene (DOM) was detected as minority species formed via reaction of Ti5c-bound CH2O with both neighboring O2c along the [1-10] direction and oxygen adatoms (Oad) at Ti5c sites along [001] on the oxidized TiO2(110) surface.},
doi = {10.1021/acs.jpcc.6b03689},
journal = {Journal of Physical Chemistry. C},
number = 23,
volume = 120,
place = {United States},
year = 2016,
month = 6
}
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