(Graph Presented) We prepared Pt nanoparticles of different particle sizes by plasma enhanced atomic layer deposition (PEALD) on the native oxide surface layer of Ti thin films, and investigated the Pt particle size effect on the electrocatalytic activity towards methanol oxidation reaction (MOR) in acidic media. The average Pt nanoparticles size ranges from 3 nm to 7 nm depending on the number of the PEALD reaction cycles. The electronic interaction between Pt nanoparticles and the TiO2 support is insignificant according to x-ray photoelectron spectroscopy analyses, suggesting that the influence of the Pt particle size on the electrocatalytic activity can be mainly described by the bifunctional mechanism. From cyclic voltammetry measurements, Pt particles of smaller size have a better CO tolerance in MOR. We proposed the reaction steps for the electrooxidation of CO adspecies on Pt nanoparticles on the basis of the bifunctional mechanism. The electrode with Pt nanoparticles of ∼5 nm in size shows the best electrocatalytic performance in terms of CO tolerance and electrochemical stability.
- Bifunctional mechanism
- Electronic effect
- Methanol oxidation reaction
- Plasma-enhanced atomic layer deposition
- Pt nanoparticle