Very low amount of TiO sub(2) on N-doped carbon nanotubes significantly improves oxygen reduction activity and stability of supported Pt nanoparticles

• Published in: Physical chemistry chemical physics : PCCP Vol. 17; no. 16; pp. 10767 - 10773
• Main Authors: Zhao, Anqi, Masa, Justus, Xia, Wei
• Format: Journal Article
• Language: English
• Published: 01.04.2015
• Subjects: Carbon; Carbon nanotubes; Chemical vapor deposition; Doping; Electrocatalysis; Platinum; Semiconductors; Titanium dioxide
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c5cp00369e

Electrochemical corrosion is a major problem for carbon materials used in electrocatalysis. Highly dispersed TiO sub(2) was deposited on O-functionalized and N-doped carbon nanotubes by chemical vapour deposition to tackle the carbon corrosion problem. Very low Ti loadings of about 1 wt% were applied to minimize the negative influence of TiO sub(2) as a semiconductor on the high conductivity of carbon materials. Both N doping and TiO sub(2) coating facilitate strong metal-support interactions and favour the formation of small Pt particles. N doping improved the intrinsic catalytic activity of the carbon support and enhanced the conductivity due to the removal of surface oxygen groups, while the negative effect of TiO sub(2) on conductivity is counterbalanced by its promoting effect on metal-support interactions leading to enhanced overall catalytic performance. Pt/TiO sub(2)/NCNTs showed the highest ORR activity, and significantly outperformed Pt/NCNTs in electrochemical stability tests.