title: Electrochemically Identifying Degradation Pathways of Carbon-Supported Pt Catalysts Assists in Designing Highly Durable Catalysts.
abstract: Supported Pt catalysts are considered highly efficient in many applications because of their unique catalytic properties. Their poor durability hampers their use in practical applications, particularly in novel energy-conversion devices such as fuel cells. A facile electrochemical procedure that combines the evaluation of the electrochemical surface area with a breakthrough in direct electrochemical quantification of the Pt content was utilized. Catalytic performance-related factors and kinetics of Pt nanoparticle (Ptnano) growth on a carbon substrate were probed under high-temperature annealing and ambient-temperature potential polarization, respectively. Apart from the Pt dissolution/redeposition pathway, we demonstrated that the crystal migration/coalescence pathway in catalyst degradation could not be ignored at ambient temperature. We report the enhanced durability and long-term activity of carbon-supported Pt catalysts, where the Ptnanosurface was partially encapsulated by nonspecific noble metal clusters; inhibition of the migration/coalescence pathway and effective exposure of Ptnanosurface active sites led to such enhancements.
authors.affiliation: Department of Chemistry, National Chung Hsing University , 145 Xingda Road, Taichung 402, Taiwan, R.O.C.
authors.forename: Jing-Fang
authors.initials: JF
authors.lastname: Huang
authors.affiliation: Department of Chemistry, National Chung Hsing University , 145 Xingda Road, Taichung 402, Taiwan, R.O.C.
authors.forename: Hsin-Ying
authors.initials: HY
authors.lastname: Hsiao
keywords: ORR; catalyst; degradation; fuel cell; noble metal cluster; platinum