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Title: Destruction of SO2 on Au and Cu Nanoparticles Dispersed on MgO(100) and CeO2(111)

Abstract

When going from periodic surfaces to isolated clusters or nanoparticles, there is a big increase in the reactivity of Au and Cu toward SO{sub 2}. Density functional calculations indicate that the enhancement in the SO{sub 2} adsorption energy is due to the presence of corner sites (i.e., metal atoms with a low coordination number) and the fluxionality of the nanoparticles. Therefore, small Au particles bind SO{sub 2} stronger than a periodic Au(100) surface. However, the S {leftrightarrow} Au and O {leftrightarrow} Au interactions are not strong enough to induce the rupture of the S-O bonds. In contrast, the dissociation of SO{sub 2} on Cu particles is a very exothermic process, even more exothermic than on a periodic Cu(100) surface. Experiments of synchrotron-based high-resolution photoemission and X-ray absorption spectroscopy show big differences in the DeSOx activity of Au and Cu nanoparticles dispersed on MgO(100) and CeO{sub 2}(111). The heat of adsorption of the SO{sub 2} on Au nanoparticles supported on MgO(100) or CeO{sub 2}(111) was 0.2 to 0.4 eV larger than on Au(100) with negligible dissociation of the molecule. The full decomposition of SO{sub 2} was observed only after O vacancies were introduced in the ceria support. The O vacancies inmore » ceria either played a direct role in the dissociation of SO{sub 2} (cracking of the molecule at the oxide-metal interface) or enhanced the chemical activity of the supported Au nanoparticles. The addition of Cu particles to MgO(100) or CeO{sub 2}(111) generates systems that are extremely active for the destruction of SO{sub 2}. At 100-150 K, the SO{sub 2} adsorbs molecularly on the supported Cu particles. Heating to temperatures above 200 K leads to massive dissociation of the SO{sub 2}. A comparison of the behavior of SO{sub 2} on Cu/MgO(100) and Cu/CeO{sub 2-x}(111) shows how important the reducibility of the oxide support in DeSOx operations can be.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
DOE - OFFICE OF SCIENCE
OSTI Identifier:
1019945
Report Number(s):
BNL-95791-2011-JA
Journal ID: ISSN 1089-5639; TRN: US201115%%581
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry A
Additional Journal Information:
Journal Volume: 114; Journal Issue: 11; Journal ID: ISSN 1089-5639
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION SPECTROSCOPY; ADSORPTION; ADSORPTION HEAT; ATOMS; COORDINATION NUMBER; DISSOCIATION; FUNCTIONALS; HEATING; OXIDES; PHOTOEMISSION; RUPTURES; THERMODYNAMIC ACTIVITY; VACANCIES; national synchrotron light source

Citation Formats

Rodriguez, J, Liu, P, Perez, M, Liu, G, and Hrbek, J. Destruction of SO2 on Au and Cu Nanoparticles Dispersed on MgO(100) and CeO2(111). United States: N. p., 2010. Web. doi:10.1021/jp905761s.
Rodriguez, J, Liu, P, Perez, M, Liu, G, & Hrbek, J. Destruction of SO2 on Au and Cu Nanoparticles Dispersed on MgO(100) and CeO2(111). United States. https://doi.org/10.1021/jp905761s
Rodriguez, J, Liu, P, Perez, M, Liu, G, and Hrbek, J. Fri . "Destruction of SO2 on Au and Cu Nanoparticles Dispersed on MgO(100) and CeO2(111)". United States. https://doi.org/10.1021/jp905761s.
@article{osti_1019945,
title = {Destruction of SO2 on Au and Cu Nanoparticles Dispersed on MgO(100) and CeO2(111)},
author = {Rodriguez, J and Liu, P and Perez, M and Liu, G and Hrbek, J},
abstractNote = {When going from periodic surfaces to isolated clusters or nanoparticles, there is a big increase in the reactivity of Au and Cu toward SO{sub 2}. Density functional calculations indicate that the enhancement in the SO{sub 2} adsorption energy is due to the presence of corner sites (i.e., metal atoms with a low coordination number) and the fluxionality of the nanoparticles. Therefore, small Au particles bind SO{sub 2} stronger than a periodic Au(100) surface. However, the S {leftrightarrow} Au and O {leftrightarrow} Au interactions are not strong enough to induce the rupture of the S-O bonds. In contrast, the dissociation of SO{sub 2} on Cu particles is a very exothermic process, even more exothermic than on a periodic Cu(100) surface. Experiments of synchrotron-based high-resolution photoemission and X-ray absorption spectroscopy show big differences in the DeSOx activity of Au and Cu nanoparticles dispersed on MgO(100) and CeO{sub 2}(111). The heat of adsorption of the SO{sub 2} on Au nanoparticles supported on MgO(100) or CeO{sub 2}(111) was 0.2 to 0.4 eV larger than on Au(100) with negligible dissociation of the molecule. The full decomposition of SO{sub 2} was observed only after O vacancies were introduced in the ceria support. The O vacancies in ceria either played a direct role in the dissociation of SO{sub 2} (cracking of the molecule at the oxide-metal interface) or enhanced the chemical activity of the supported Au nanoparticles. The addition of Cu particles to MgO(100) or CeO{sub 2}(111) generates systems that are extremely active for the destruction of SO{sub 2}. At 100-150 K, the SO{sub 2} adsorbs molecularly on the supported Cu particles. Heating to temperatures above 200 K leads to massive dissociation of the SO{sub 2}. A comparison of the behavior of SO{sub 2} on Cu/MgO(100) and Cu/CeO{sub 2-x}(111) shows how important the reducibility of the oxide support in DeSOx operations can be.},
doi = {10.1021/jp905761s},
url = {https://www.osti.gov/biblio/1019945}, journal = {Journal of Physical Chemistry A},
issn = {1089-5639},
number = 11,
volume = 114,
place = {United States},
year = {2010},
month = {1}
}