title: Well-dispersed high-loading pt nanoparticles supported by shell-core nanostructured carbon for methanol electrooxidation.
abstract: Shell-core nanostructured carbon materials with a nitrogen-doped graphitic layer as a shell and pristine carbon black particle as a core were synthesized by carbonizing the hybrid materials containing in situ polymerized aniline onto carbon black. In an N-doped carbon layer, the nitrogen atoms substitute carbon atoms at the edge and interior of the graphene structure to form pyridinic N and quaternary N structures, respectively. As a result, the carbon structure becomes more compact, showing curvatures and disorder in the graphene stacking. In comparison with nondoped carbon, the N-doped one was proved to be a suitable supporting material to synthesize high-loading Pt catalysts (up to 60 wt %) with a more uniform size distribution and stronger metal-support interactions due to its high electrochemically accessible surface area, richness of disorder and defects, and high electron density. Moreover, the more rapid charge-transfer rates over the N-doped carbon material are evidenced by the high crystallinity of the graphitic shell layer with nitrogen doping as well as the low charge-transfer resistance at the electrolyte/electrode interface. Beneficial roles of nitrogen doping can be found to enhance the CO tolerance of Pt catalysts. Accordingly, an improved performance in methanol oxidation was achieved on a high-loading Pt catalyst supported by N-doped carbon. The enhanced catalytic properties were extensively discussed based on mass activity (Pt utilization) and intrinsic activity (charge-transfer rate). Therefore, N-doped carbon layers present many advantages over nondoped ones and would emerge as an interesting supporting carbon material for fuel cell electrocatalysts.
authors.affiliation: Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001, China. wugang@lanl.gov
authors.forename: Gang
authors.initials: G
authors.lastname: Wu
authors.forename: Deyu
authors.initials: D
authors.lastname: Li
authors.forename: Changsong
authors.initials: C
authors.lastname: Dai
authors.forename: Dianlong
authors.initials: D
authors.lastname: Wang
authors.forename: Ning
authors.initials: N
authors.lastname: Li