TY - JOUR
T1 - H 2 Dissociation on Noble Metal Single Atom Catalysts Adsorbed on and Doped into CeO 2 (111)
AU - Righi, Giulia
AU - Magri, Rita
AU - Selloni, Annabella
N1 - Funding Information:
This work was supported by DoE-BES, Division of Chemical Sciences, Geosciences and Biosciences, under Award DESC0007347. We acknowledge use of the computational resources of TIGRESS high performance computer center at Princeton University. We thank the University of Modena and Reggio Emilia for financial support through the Bando Mobilità Giovani Ricercatori and the project FAR 2016.
Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/4/18
Y1 - 2019/4/18
N2 - We used density functional theory (DFT) calculations to investigate the dissociation of H 2 on an Ag single atom catalyst adsorbed on the pristine CeO 2 (111) surface (Ag/CeO 2 ), or substituting a surface Ce atom on the reduced (Ag:CeO 2-x ) and partially hydrogenated (Ag:H-CeO 2 ) surfaces. The initial state of the H 2 dissociation reaction in the different investigated models corresponds to distinct oxidation states, +1, +2, or +3, of the Ag atom, thus allowing us to examine the influence of the charge transfers between the noble metal, the oxide, and the hydrogen atoms on the reaction pathway and activation energy. In all investigated models, the computed barrier of H 2 dissociation is lowered by about 0.6 eV in comparison to that on metal-free CeO 2 . On Ag/CeO 2 and Ag:CeO 2-x , also the energy of H 2 dissociative adsorption is smaller than that on metal-free ceria. These results suggest that CeO 2 modified with dispersed Ag atoms is a promising anode material for proton exchange membrane fuel cells. Further comparison of our results for Ag to analogous calculations for Cu and Au single atom catalysts reveals trends in the computed barriers that can be related to the change of the metal oxidation state in the reaction.
AB - We used density functional theory (DFT) calculations to investigate the dissociation of H 2 on an Ag single atom catalyst adsorbed on the pristine CeO 2 (111) surface (Ag/CeO 2 ), or substituting a surface Ce atom on the reduced (Ag:CeO 2-x ) and partially hydrogenated (Ag:H-CeO 2 ) surfaces. The initial state of the H 2 dissociation reaction in the different investigated models corresponds to distinct oxidation states, +1, +2, or +3, of the Ag atom, thus allowing us to examine the influence of the charge transfers between the noble metal, the oxide, and the hydrogen atoms on the reaction pathway and activation energy. In all investigated models, the computed barrier of H 2 dissociation is lowered by about 0.6 eV in comparison to that on metal-free CeO 2 . On Ag/CeO 2 and Ag:CeO 2-x , also the energy of H 2 dissociative adsorption is smaller than that on metal-free ceria. These results suggest that CeO 2 modified with dispersed Ag atoms is a promising anode material for proton exchange membrane fuel cells. Further comparison of our results for Ag to analogous calculations for Cu and Au single atom catalysts reveals trends in the computed barriers that can be related to the change of the metal oxidation state in the reaction.
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U2 - 10.1021/acs.jpcc.9b00609
DO - 10.1021/acs.jpcc.9b00609
M3 - Article
AN - SCOPUS:85064401583
SN - 1932-7447
VL - 123
SP - 9875
EP - 9883
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 15
ER -