A cerium oxide (CeOx) nanowire of approximately 35 nm diameter was fabricated using an alco-thermal method. Platinum nanoparticles were formed at the interface between Ce(OH)3 and CeOx nanowire which consisted of slightly ionized Pt, Ce3+ and Ce4+. Additionally, Pt nanoparticle sizes were found to be less than 2 nm. The electrochemically active surface area of the Pt-CeOx nanowire/C electrode reaches 152 m2 gPt-1. It is quite high as compared with the same parameter observed for commercially available Pt/C electrodes of 51 m2 gPt-1. This indicates that both CeOx nanowire and Ce(OH)3 can provide useful interfacial reaction space at the nanoscale for formation of small Pt particles. The platinum content of Pt-loaded CeOx nanowire/C can be low such as 0.975 mg ml-1 using this interface reaction space, as compared to 3.90 mg ml-1 in current industrial fuel cell anode materials. While the Pt content in the present nanostructured Pt-CeOx nanowire/C anode is much lower than commercially available Pt/C anodes, the carbon monoxide (CO) tolerance of Pt in the present nanostructured Pt-CeOx nanowire/C anode is superior in the methanol electro-oxidation reaction, which is an important electrode reaction at the anodic side of fuel cells. Based on the experimental data, it is concluded that the interface between Pt and CeO x nanowire plays a key role in enhancement of the electrochemically active surface area of the Pt-CeOx nanowire/C electrode and improvement of CO tolerance of Pt in Pt-CeOx nanowire/C for fuel cell applications.
ASJC Scopus subject areas
- 化学 (全般)