Symmetric growth of Pt ultrathin nanowires from dumbbell nuclei for use as oxygen reduction catalysts
Nanowire, dumbbell, nanocube, chromium hexacarbonyl, fuel cell, oxygen reduction reaction
ABSTRACT This work demonstrates the synthesis of Pt ultrathin nanowires assisted by chromium hexacarbonyl [Cr(CO)6]. The nanowires exhibit a uniform diameter of 2–3 nm. The length can reach up to several microns. It was found that Cr species produced dumbbell-like nuclei which play a pivotal role in the formation of the Pt nanowires. Such Pt nanowires can be tuned to nanocubes by simply decreasing the concentration of [Cr(CO)6]. Compared to a commercial Pt/C catalyst (45 wt%, Vulcan, Tanaka) and Pt black (fuel cell grade, Sigma), the synthesized Pt nanowires exhibit superior performance in electrocatalytic oxygen reduction with a specific activity of 0.368 mA/cm2, which was 2.7 and 1.8 times greater than that of Pt/C (0.138 mA/cm2) and Pt black (0.202 mA/cm2), respectively. The mass activity of Pt nanowires (0.088 mA/µg) is 2.3 times that of Pt black (0.038 mA/µg) and comparable to that of Pt/C (0.085 mA/µg).
Tsinghua University Press
Qiangfeng Xiao,Mei Cai,Michael P. Balogh,Misle M. Tessema,Yunfeng Lu, Symmetric growth of Pt ultrathin nanowires from dumbbell nuclei for use as oxygen reduction catalysts. NanoRes.2012, 5(3): 145–151