skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Reactivity of Transition Metals (Pd, Pt, Cu, Ag, Au) toward Molecular Hydrogen Dissociation: Extended Surfaces versus Particles Supported on TiC(001) or Small Is Not Always Better and Large Is Not Always Bad

Abstract

The reactivity of Pd{sub 4}, Pt{sub 4}, Cu{sub 4}, Ag{sub 4}, and Au{sub 4} clusters supported on TiC(001) toward molecular hydrogen dissociation has been studied by means of density functional based theory and periodic models and compared to that of the (111) and (001) surfaces. Pd{sub 4} and Pt{sub 4} interact rather strongly with the TiC(001) substrate, but the interaction of molecular hydrogen with the Pd{sub 4}/TiC and Pt{sub 4}/TiC systems is also very strong. As a consequence of the substantial admetal {leftrightarrow} carbide interactions, the adsorbed H{sub 2} molecule becomes more difficult to dissociate than on the corresponding extended (111) and (001) surfaces. Here, having a small supported particle does not lead to an enhanced chemical activity. On the contrary, for the Cu{sub 4}/TiC, Ag{sub 4}/TiC, and Au{sub 4}/TiC systems the combination of the small size of the particle and the polarization induced by the underlying carbide facilitates the dissociation of the hydrogen molecule with respect to the case of the extended surfaces. Here, the reduced size effectively enhances the activity of the supported particle. Thus, our results for the M(111), M(100), and M{sub 4}/TiC(001) systems show the complex interplay that can take place among the nature of themore » admetal, particle size effects, and support interactions.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
USDOE SC OFFICE OF SCIENCE (SC)
OSTI Identifier:
1040497
Report Number(s):
BNL-94850-2011-JA
Journal ID: ISSN 1932-7447; R&D Project: CO-009; KC0302010; TRN: US201210%%673
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Journal Name:
The Journal of Physical Chemistry C
Additional Journal Information:
Journal Volume: 115; Journal Issue: 23; Journal ID: ISSN 1932-7447
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CARBIDES; DISSOCIATION; FUNCTIONALS; HYDROGEN; PARTICLE SIZE; POLARIZATION; THERMODYNAMIC ACTIVITY; TRANSITION ELEMENTS; national synchrotron light source

Citation Formats

Rodriguez, J A, Gomez, T, Florez, E, and Illas, F. Reactivity of Transition Metals (Pd, Pt, Cu, Ag, Au) toward Molecular Hydrogen Dissociation: Extended Surfaces versus Particles Supported on TiC(001) or Small Is Not Always Better and Large Is Not Always Bad. United States: N. p., 2011. Web.
Rodriguez, J A, Gomez, T, Florez, E, & Illas, F. Reactivity of Transition Metals (Pd, Pt, Cu, Ag, Au) toward Molecular Hydrogen Dissociation: Extended Surfaces versus Particles Supported on TiC(001) or Small Is Not Always Better and Large Is Not Always Bad. United States.
Rodriguez, J A, Gomez, T, Florez, E, and Illas, F. Wed . "Reactivity of Transition Metals (Pd, Pt, Cu, Ag, Au) toward Molecular Hydrogen Dissociation: Extended Surfaces versus Particles Supported on TiC(001) or Small Is Not Always Better and Large Is Not Always Bad". United States.
@article{osti_1040497,
title = {Reactivity of Transition Metals (Pd, Pt, Cu, Ag, Au) toward Molecular Hydrogen Dissociation: Extended Surfaces versus Particles Supported on TiC(001) or Small Is Not Always Better and Large Is Not Always Bad},
author = {Rodriguez, J A and Gomez, T and Florez, E and Illas, F},
abstractNote = {The reactivity of Pd{sub 4}, Pt{sub 4}, Cu{sub 4}, Ag{sub 4}, and Au{sub 4} clusters supported on TiC(001) toward molecular hydrogen dissociation has been studied by means of density functional based theory and periodic models and compared to that of the (111) and (001) surfaces. Pd{sub 4} and Pt{sub 4} interact rather strongly with the TiC(001) substrate, but the interaction of molecular hydrogen with the Pd{sub 4}/TiC and Pt{sub 4}/TiC systems is also very strong. As a consequence of the substantial admetal {leftrightarrow} carbide interactions, the adsorbed H{sub 2} molecule becomes more difficult to dissociate than on the corresponding extended (111) and (001) surfaces. Here, having a small supported particle does not lead to an enhanced chemical activity. On the contrary, for the Cu{sub 4}/TiC, Ag{sub 4}/TiC, and Au{sub 4}/TiC systems the combination of the small size of the particle and the polarization induced by the underlying carbide facilitates the dissociation of the hydrogen molecule with respect to the case of the extended surfaces. Here, the reduced size effectively enhances the activity of the supported particle. Thus, our results for the M(111), M(100), and M{sub 4}/TiC(001) systems show the complex interplay that can take place among the nature of the admetal, particle size effects, and support interactions.},
doi = {},
url = {https://www.osti.gov/biblio/1040497}, journal = {The Journal of Physical Chemistry C},
issn = {1932-7447},
number = 23,
volume = 115,
place = {United States},
year = {2011},
month = {5}
}