4 Catalyst Materials for Oxygen Reduction Reaction
111
Fig. 4.17 a TEM images of Pt nanowires, the inset is the HRTEM image of Pt nanowires, b selected
area electron diffraction images, c ORR Curve of Pt nanowires and Pt/C catalyst in 0.1 M HClO 4
d Comparison of ORR specific activity of Pt nanowires and Pt/C catalysts [185]. Reprinted with
permission. [185] Copyright (2010) American Chemical Society
structure and double twin boundaries. Pt 3 Ni icosahedrons are basically composed of
{111} facets. Among the Pt–M icosahedral nanocrystals, the ORR activity of Pt 3 Ni
was the highest, and the specific activity and mass activity at 0.9 V (vs. RHE) reached
1.83 mA cm
−2
Pt and 620 mA mg
−1
Pt . In addition, they also compared the ORR
activity of this Pt 3 Ni decahedrons and Pt 3 Ni octahedrons, and found that the specific
activity of the Pt 3 Ni decahedrons was 50% higher than that of the Pt3Ni octahedrons.
The density functional theory and molecular dynamic calculation results show that
this difference in ORR performance may be due to the electronic effect caused by
strain. Choi et al. [209] used Pt(acac) 2 and Ni(acac) 2 precursor, and added the above
precursors to a mixed solution of oleic acid, oleylamine, and benzyl ether. Under
the protection of Ar gas, W(CO) 6 was added at 130 °C, then the temperature was
raised to 230 °C, and then the Ar gas was stopped, and the reaction was performed
at 230 °C for 40 min to obtain Pt–Ni octahedrons. The size of the obtained Pt–Ni
octahedron is 9 nm, and the addition of W(CO) 6 as a CO gas source can promote
the formation of {111} crystal planes under the effcet of Ni. They further treated the
obtained Pt–Ni octahedrons with acetic acid for 2 and 10 h, and finally loaded these
Pt–Ni octahedrons onto the carbon powder. The mass activity of Pt–Ni octahedrons
at 0.9 V (vs. RHE) before acetic acid treatment reached 3100 mA mg
−1
Pt , while
the Pt–Ni octahedrons after 2 h acetic acid treatment at 0.9 V (vs. RHE) reached
3300 mA mg
−1
Pt , which is 17 times of the commercial Pt/C (200 mA mg
−1
Pt ). Their
111
Fig. 4.17 a TEM images of Pt nanowires, the inset is the HRTEM image of Pt nanowires, b selected
area electron diffraction images, c ORR Curve of Pt nanowires and Pt/C catalyst in 0.1 M HClO 4
d Comparison of ORR specific activity of Pt nanowires and Pt/C catalysts [185]. Reprinted with
permission. [185] Copyright (2010) American Chemical Society
structure and double twin boundaries. Pt 3 Ni icosahedrons are basically composed of
{111} facets. Among the Pt–M icosahedral nanocrystals, the ORR activity of Pt 3 Ni
was the highest, and the specific activity and mass activity at 0.9 V (vs. RHE) reached
1.83 mA cm
−2
Pt and 620 mA mg
−1
Pt . In addition, they also compared the ORR
activity of this Pt 3 Ni decahedrons and Pt 3 Ni octahedrons, and found that the specific
activity of the Pt 3 Ni decahedrons was 50% higher than that of the Pt3Ni octahedrons.
The density functional theory and molecular dynamic calculation results show that
this difference in ORR performance may be due to the electronic effect caused by
strain. Choi et al. [209] used Pt(acac) 2 and Ni(acac) 2 precursor, and added the above
precursors to a mixed solution of oleic acid, oleylamine, and benzyl ether. Under
the protection of Ar gas, W(CO) 6 was added at 130 °C, then the temperature was
raised to 230 °C, and then the Ar gas was stopped, and the reaction was performed
at 230 °C for 40 min to obtain Pt–Ni octahedrons. The size of the obtained Pt–Ni
octahedron is 9 nm, and the addition of W(CO) 6 as a CO gas source can promote
the formation of {111} crystal planes under the effcet of Ni. They further treated the
obtained Pt–Ni octahedrons with acetic acid for 2 and 10 h, and finally loaded these
Pt–Ni octahedrons onto the carbon powder. The mass activity of Pt–Ni octahedrons
at 0.9 V (vs. RHE) before acetic acid treatment reached 3100 mA mg
−1
Pt , while
the Pt–Ni octahedrons after 2 h acetic acid treatment at 0.9 V (vs. RHE) reached
3300 mA mg
−1
Pt , which is 17 times of the commercial Pt/C (200 mA mg
−1
Pt ). Their