Chapter 5
Adatoms, Defects, and Kink Edges
Abstract Atoms with even fewer neighbors perform both atomic like and bulk like
associated with shorter and stronger interatomic bonds. The bond contraction raises
the local charge and energy density and the bond strength gain deepens the local
potential well and entraps the core electrons. The locally and densely entrapped core
electrons in turn polarize the valence electrons. The subjective valence electron polarization occurs to those atoms with unpaired lone electrons in the s orbitals such as Rh,
Au, Ag, Cu and the unpaired 4f
14 5d
4 6s
2 (5d
5 6s
1 seems to be stable) electrons of the
W adatoms and Mo(4d
5 5s
1 ) as well. However, the Co(3d
7 4s
2 ) with fully-occupied
s electrons and the Re(5d
5 6s
2 ) with semi-occupied d electrons exhibit entrapment
dominance. The undercoordination resolved valence electron entrapment or polarization laid foundations for the extraordinary catalytic ability of the excessively
undercoordinated atoms and the dispersed single atom.
Highlights
• Atoms with even fewer neighbors than that at the flat skin enhance the BOLS-NEP
effect.
• Bond between a metallic adatom and its substrate is 18% shorter and 21% stronger.
• Shared by Re and Co edge atoms, quantum entrapment makes Pt adatom an
acceptor-type catalyst.
• Shared by Au, Ag, Cu, Mo, and W adatoms, polarization entitles Rh adatom a
donor-type catalyst.
5.1 Observations
5.1.1 XPS Detection
Interaction between undercoordinated atoms distinguishes nanocrystals from their
bulk parents in terms of size dependency of known properties and size derivacy of new
properties. Size dependence means that the quantities such as the elastic modulus and
the melting point remain no longer constant but change with the shape and size of the
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
C. Q. Sun, Electron and Phonon Spectrometrics,
https://doi.org/10.1007/978-981-15-3176-7_5
81
Adatoms, Defects, and Kink Edges
Abstract Atoms with even fewer neighbors perform both atomic like and bulk like
associated with shorter and stronger interatomic bonds. The bond contraction raises
the local charge and energy density and the bond strength gain deepens the local
potential well and entraps the core electrons. The locally and densely entrapped core
electrons in turn polarize the valence electrons. The subjective valence electron polarization occurs to those atoms with unpaired lone electrons in the s orbitals such as Rh,
Au, Ag, Cu and the unpaired 4f
14 5d
4 6s
2 (5d
5 6s
1 seems to be stable) electrons of the
W adatoms and Mo(4d
5 5s
1 ) as well. However, the Co(3d
7 4s
2 ) with fully-occupied
s electrons and the Re(5d
5 6s
2 ) with semi-occupied d electrons exhibit entrapment
dominance. The undercoordination resolved valence electron entrapment or polarization laid foundations for the extraordinary catalytic ability of the excessively
undercoordinated atoms and the dispersed single atom.
Highlights
• Atoms with even fewer neighbors than that at the flat skin enhance the BOLS-NEP
effect.
• Bond between a metallic adatom and its substrate is 18% shorter and 21% stronger.
• Shared by Re and Co edge atoms, quantum entrapment makes Pt adatom an
acceptor-type catalyst.
• Shared by Au, Ag, Cu, Mo, and W adatoms, polarization entitles Rh adatom a
donor-type catalyst.
5.1 Observations
5.1.1 XPS Detection
Interaction between undercoordinated atoms distinguishes nanocrystals from their
bulk parents in terms of size dependency of known properties and size derivacy of new
properties. Size dependence means that the quantities such as the elastic modulus and
the melting point remain no longer constant but change with the shape and size of the
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
C. Q. Sun, Electron and Phonon Spectrometrics,
https://doi.org/10.1007/978-981-15-3176-7_5
81