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Title: Strong Temperature Dependence in the Reactivity of H 2 on RuO 2 (110)

Abstract

The ability of hydrogen to facilitate many types of heterogeneous catalysis starts with its adsorption. As such, understanding the temperature-dependence sticking of H2 is critical toward controlling and optimizing catalytic conditions in those cases where adsorption is rate-limiting. In this work, we examine the temperature-dependent sticking of H2/D2 to the clean RuO2(110) surface using the King & Wells molecular beam approach, temperature programmed desorption (TPD) and scanning tunneling microscopy (STM). We show that the sticking probability (molecular or dissociative) of H2/D2 on this surface is highly temperature-dependent, decreasing from ~0.4-0.5 below 25 K to effectively zero above 200 K. Both STM and TPD reveal that OH/OD formation is severely limited for adsorption temperatures above ~150 K. Previous literature reports of extensive surface hydroxylation from H2/D2 exposures at room temperature were most likely the result of inadvertent contamination brought about from dosing by chamber backfilling.

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:
1340798
Report Number(s):
PNNL-SA-119145
Journal ID: ISSN 1948-7185; 49642; 48287; KC0302010
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry Letters; Journal Volume: 7; Journal Issue: 15
Country of Publication:
United States
Language:
English
Subject:
RuO2(110); hydrogen; adsorption; STM; Environmental Molecular Sciences Laboratory

Citation Formats

Henderson, Michael A., Dahal, Arjun, Dohnálek, Zdenek, and Lyubinetsky, Igor. Strong Temperature Dependence in the Reactivity of H 2 on RuO 2 (110). United States: N. p., 2016. Web. doi:10.1021/acs.jpclett.6b01307.
Henderson, Michael A., Dahal, Arjun, Dohnálek, Zdenek, & Lyubinetsky, Igor. Strong Temperature Dependence in the Reactivity of H 2 on RuO 2 (110). United States. doi:10.1021/acs.jpclett.6b01307.
Henderson, Michael A., Dahal, Arjun, Dohnálek, Zdenek, and Lyubinetsky, Igor. 2016. "Strong Temperature Dependence in the Reactivity of H 2 on RuO 2 (110)". United States. doi:10.1021/acs.jpclett.6b01307.
@article{osti_1340798,
title = {Strong Temperature Dependence in the Reactivity of H 2 on RuO 2 (110)},
author = {Henderson, Michael A. and Dahal, Arjun and Dohnálek, Zdenek and Lyubinetsky, Igor},
abstractNote = {The ability of hydrogen to facilitate many types of heterogeneous catalysis starts with its adsorption. As such, understanding the temperature-dependence sticking of H2 is critical toward controlling and optimizing catalytic conditions in those cases where adsorption is rate-limiting. In this work, we examine the temperature-dependent sticking of H2/D2 to the clean RuO2(110) surface using the King & Wells molecular beam approach, temperature programmed desorption (TPD) and scanning tunneling microscopy (STM). We show that the sticking probability (molecular or dissociative) of H2/D2 on this surface is highly temperature-dependent, decreasing from ~0.4-0.5 below 25 K to effectively zero above 200 K. Both STM and TPD reveal that OH/OD formation is severely limited for adsorption temperatures above ~150 K. Previous literature reports of extensive surface hydroxylation from H2/D2 exposures at room temperature were most likely the result of inadvertent contamination brought about from dosing by chamber backfilling.},
doi = {10.1021/acs.jpclett.6b01307},
journal = {Journal of Physical Chemistry Letters},
number = 15,
volume = 7,
place = {United States},
year = 2016,
month = 8
}
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