Pt nanoparticles （ Pt NPs ）. catalyst. hydrogen storage media. d ~ 1 - 10 2 nm. electrodes for fuel cells. Electron states of Pt atoms on the surface of Pt NPs are remarkable !. 195 Pt NMR of Pt NPs depends on. ・ molecular size ・ chemisorbed molecules. Solid-state 195 Pt NMR.
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d ~ 1 - 102 nm
electrodes for fuel cells
Electron states of Pt atoms on
the surface of Pt NPs are remarkable !
195Pt NMR of Pt NPsdepends on
Peak positions of
commercial Pt NPs
a few MHz
The spins excited
by conventional π/2 pulses
（a few hundred kHz, at most）
Point-by-point plots of
the peak area of the spin echoes
Instruments （in Kyoto University)
variable-field cryogen-free magnet
OPENCORE NMR spectrometer
bulk Pt (n = ∞)
195PtNMR of Pt NPs
surface (n = 0)
subsurface(n = 1)
（n = 2）
the thickness of each Pt layer
NMR layer model
Kbulk: the Knight shift on bulk Pt metal
K0: the Knight shift on the surface Pt atoms
Kn: the Knight shift on the nth Pt layer
n: layer number
m: healing factor
the additional effect of hybridization of 5d and 6s band
core polarization by
5d conduction electron
electron configuration of
Pt atom: 6s25d8
→low 5d electron DOS at Fermi energy
→high 5d electron DOS at Fermi energy
195Pt NMRof Pt NPs protected by n-alkylthiols(1)
Pt complex ?
Pt complex ?
195Pt NMRof Pt NPs protected by n-alkylthiols (2)