??????????????

1
?????????????????????????? (GL ?? ?)
??????? ???????
H21
H22
H20
H23
H24
?????????? (??????????????PD)
????????? ???????????
?????? ????????????
???????????? ??????
0??????
2??????
3?????
????(?????????)??????? (?????)
?????????? (???????????)
???????????????? ????????????
?????????? ??????????
????
????
????
???????????(????????PD)
??????? ??????
??????? ?????
????????? ??????
??1????
????????
???????
2
?????????????????????????? (GL ?? ?)
??????? ???????
H20
H21
H22
H23
H24
?????????? (??????????????PD)
????????? ???????????
?????? ????????????
???????????? ??????
0??????
2??????
3?????
????(?????????)??????? (?????)
?????????? (???????????)
???????????????? ????????????
?????????? ??????????
????
????
????
???????????(????????PD)
??????? ??????
??????? ?????
????????? ??????
??1????
????????
???????
3
?????????????
Pt-Ru?????? ??????????C1?????????????????????
Pt-(CO)ads Ru-OH ? Pt Ru CO2 H e-
Pt
????????????????? ?????????????????
Ru
????????????????? ????????????????? ?????????
??????????????????
?????????????????????????????
?????????????????????????
4
300ºC?????
Pt-Ru????????
Pt-Ru??????
0.1 M KOH 1 M MeOH, 50 mV/s
Pt-Ru???????????????????????? ??????????????????
Imax 3109 nA
Imax 8108 nA
Imax 3.3109 nA
Ref) H. Uehara, Y. Okawa, Y. Sasaki, K. Uosaki,
Chem. Lett., 2009, 38, 148.
5
????????????????????
3 ????????
9 ????????
15 ????????
1 ????????
????????????????Pt-Ru?????????? 9?????????????15?
?????2?????
????? ?????????
6
???????-????????
HAADF (high-angle annular dark-field ) scanning
TEM image of Pt DNPs
I-V curves of rotating GC electrode modified
with DPNs in O2 saturated 0.5 M H2SO4 with scan
of 50 mV s-1.
CV of DPNs modified GC electrode in 0.5 M H2SO4
with scan rate 100 mV s-1.
Pt-Pd alloy
EDX Pt
EDX Pd
HRTEM
SEM
7
?????????????????????????? (GL ?? ?)
??????? ???????
H20
H21
H22
H23
H24
?????????? (??????????????PD)
????????? ???????????
?????? ????????????
???????????? ??????
0??????
2??????
3?????
????(?????????)??????? (?????)
?????????? (???????????)
???????????????? ????????????
?????????? ??????????
????
????
????
???????????(????????PD)
??????? ??????
??????? ?????
????????? ??????
??1????
????????
???????
8
????????????????
?????????? ?????????? ??????????
?????????????
?????? ?????????????????????????? ???????????????
???????
9
????????????????????????
?????????Au????
????????????????
f 500 mV
f -1000 mV
2H 2e- ? H2
??????
????
?????????????
2Had ? H2(2)
M. Kiguchi et al., Phys. Rev. B 73, 125406 (2006).
H e- Had ? H2(2)
H e- ? Had (1)
H2
H2
???????Ni???????
H
H
e-
Had
Had
Had
Had
e-
????
?????????????
????????? ?????????????(Had)???
M. Kiguchi et al., Appl. Phys. Lett. 87, 043104
(2005) T. Konishi et al., Jpn. J. Appl Phys., 45,
2000 (2006).
??? ?????????????????
10
Au???????????????
Au???????????
????? ?????
11
???Pd?????????
Length histogram of atomic contact
12
???????
Conductance trace
Low conductance lt 0.3 G0
High conductance 0.3 1.2 G0
Counts (a.u.)
Counts (a.u.)
Pd H2
Pd H2
100
80
60
40
20
0
100
80
60
40
20
0
Vibration Energy (meV)
Vibration Energy (meV)
13
???? ???
?? -Gaussian03, ATK
??
Short chain
Long chain
Pd
H
1. ?? 2. ??? 3. ?????
1.5 G0 (Exp. 1.0 G0)
0.5 G0 (Exp. 0.5 G0)
Exp. 35 meV
Exp. 31 meV, 67 meV
14
?????????????????????????? (GL ?? ?)
??????? ???????
H20
H21
H22
H23
H24
?????????? (??????????????PD)
????????? ???????????
?????? ????????????
???????????? ??????
0??????
2??????
3?????
????(?????????)??????? (?????)
?????????? (???????????)
???????????????? ????????????
?????????? ??????????
????
????
????
???????????(????????PD)
??????? ??????
??????? ?????
????????? ??????
??1????
????????
???????
15
???????????
(??????????)
1.????????????????????????????
After H2O Addition (no color change)
After O2 Bubbling (color change to green)
???????????????????????
16
?????? Monolayer Formation of a Pt-Ru Dinuclear
Complex on a Gold (111) Surface and Its
Conversion to a Pt-Ru Two-dimensional
Nanocomposite Having Electrocatalytic Activity,
H. Uehara, Y. Okawa, Y. Sasaki and K. Uosaki
Chem. Lett., 38 148 (2009) Characterization of Au
Atomic Contact in Hydrogen Environment using
Vibration Spectroscopy of a Single Molecular
Junction, M. Kiguchi, T. Nakazumi, K. Hashimoto
and K. Murakoshie-J. Surf.Sci. Nanotechnol 7, 53
(2008) Dynamic Characterization of the
Post-breaking Behavior of a NanowireJ. Zhao, K.
Murakoshi, X. Yin, M. Kiguchi, Y. Guo, N. Wang,
S. Liang and H. LiuJ. Phys. Chem. C 112(50),
20088 (2008) Stable iron-group metal nano contact
showing quantized conductance in solutionT.
Konishi, M. Kiguch and K. MurakoshiSurf. Sci.
602, 2333 (2008) In-situ preparation of a single
molecular junction with mechanically controllable
break junctions in vaccumM Kiguchi, N Sekiguchi
and K MurakoshiJ. Phys. Conf. Ser. 100, 052059
(2009). Three reversible states controlled on a
gold monoatomic contact by the electrochemical
potentialM. Kiguchi, T. Konishi, K. Hasegawa, S.
Shidara, K. MurakoshiPhys. Rev. B 77,245421
(2009)
?????????????????????????? (GL ?? ?)
??????? ???????
H20 - H21 ?????
?????????? (????????????????) ????(?????????)?????
?? (?????)
Pt ? Ru ???????????????????????? Pt Ru
????????????????? Pt Ru ???????????Pt?????????
?????????????? ???????????????????????
?????????? (???????????)
??????????????????????? ?????????????????????
????? ???????????????????????
???????????(??????????)
????????????????????? ????????? Mo
??????????????? ? ????????????????????????????
17
???-??????????
?????
??????????????Zhang
Heated at 300oC on Au(111)
Pt-Ni catalyst
?????????????
18
?????
????????
????????????????????????????????????????
??????????????????
N????????????????
M. Lefevre et al., Science 71, 324(2009)
J. Wei et al., Appl. Phys. Lett. 94, 102108(2009)
????????????? ???????
?????????????????
A. Hashimoto et al., Nature 430, 870(2004)
S Tang et al., J. Chem. Phys. 131, 114706(2009)
19
?????
????????
???????????? ??????????????
?????????? ??????????
785 nm (1.58 eV) 0.15 mW
h?
H2O
Au
Au
???????????????
????????????
233 cm-1 (11,3)
RBM
D-band
?????????????????
???????????????
???????????????