title: Segregated Pt on Pd nanotubes for enhanced oxygen reduction activity in alkaline electrolyte.
abstract: Nanoscaled Pt domains were integrated with Pd nanotubes via vapor deposition to yield a highly active electrocatalyst for the oxygen reduction reaction (ORR) in alkaline media. The surface-area-normalized ORR activity of these bi-metallic Pt-on-Pd nanotubes (PtPdNTs) was nearly 6× the corresponding carbon-supported Pt nanoparticle (Pt/C) activity at 0.9 V vs. RHE (1.5 vs. 0.24 mA cmmetal(-2), respectively). Furthermore, the high specific activity of the PtPdNTs was achieved without sacrificing mass-normalized activity, which is more than twice that of Pt/C (0.333 A mgPtPdNT(-1)vs. 0.141 A mgPt/C(-1)) and also greater than that of Pd/C (0.221 A mgPd/C(-1)). We attribute the enhancements in specific and mass activity to modifications of the segregated Pt electronic structure and to nanoscale porosity, respectively.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, USA. apapandrew@utk.edu.
authors.forename: Samuel
authors.initials: S
authors.lastname: St John
authors.forename: Robert W
authors.initials: RW
authors.lastname: Atkinson
authors.forename: Ondrej
authors.initials: O
authors.lastname: Dyck
authors.forename: Cheng-Jun
authors.initials: CJ
authors.lastname: Sun
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Zawodzinski
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Papandrew