Supporting Information
Synthesis of Composition-tunable Octahedral Pt-Cu Alloy
Nanocrystals by Controlling Reduction Kinetics of Metal
Precursors
Yanyan Jia, Zhenming Cao, Qiaoli Chen, Yaqi Jiang*, Zhaoxiong Xie*, and Lansun
Zheng
State Key Laboratory for Physical Chemistry of Solid Surfaces and Department of
Chemistry, College of Chemistry and Chemical Engineering, Xiamen University,
Xiamen, China, 361005
E-mail: zxxie@xmu.edu.cn, yqjiang@xmu.edu.cn
Figure S1. The XRD patterns of the samples prepared by using different amount of
n-butylamine.
Figure S2. The SEM images of the samples prepared by using different amount of
n-butylamine: (a) 0.0 mmol, (b) 0.1 mmol, (c) 0.2 mmol, (d) 0.5 mmol. The SEM
images show that the octahedral shape was maintained very well.
Figure S3. The pictures showing the yield of Pt nanocrystals at different reaction
times with (No.1, 3, 5 samples)/without (No. 2, 4, 6 samples) n-butylamine. It can be
seen clearly that the as-prepared Pt NCs with n-butylamine (the former) is less than
that formed in the absence of n-butylamine (the latter) at each reaction time. We thus
deduced that the reducing rate of Pt in the presence of n-butylamine is much slower
than that without n-butylamine.
Figure S4. The CV curves measured for three Pt-Cu alloy catalysts with different
composition and commercial Pt black in an N2-purged solution of 0.5 M H2SO4. Scan
rate: 50 mV s-1.
Typical features for the hydrogen desorption description are clearly observed in CV
curves of the catalysts in an N2-purged solution of 0.5 M H2SO4. From the
representative CV curves in H2SO4 solution, we can see that the voltammogram
features in hydrogen underpotential deposition (HUPD) region are similar to those
reported for the commercial Pt black. For the three Pt-Cu alloy, the HUPD region
shows a nearly features. The ECSA was calculated by measuring the charges collected
in the hydrogen desorption region from -0.2 to 0.1 V. The ECSA are 1.14, 1.46, 1.92
and 2.23 cm2 for PtCu, Pt38Cu62, PtCu3 and Pt black. There is an oxidation peak at
about 0.48 V for three Pt-Cu alloy compared with Pt black, indicating Cu can be
electrochemically dissolved, and the current density increases with Cu content
increase displaying Cu dissolution more apparent.