title: Enhancing the activity and tuning the mechanism of formic acid oxidation at tetrahexahedral Pt nanocrystals by Au decoration.
abstract: Tetrahexahedral Pt nanocrystals (THH Pt NCs), bound by high index facets, belong to an emerging class of nanomaterials that promise to bridge the gap between model and practical electrocatalysts. The atomically stepped surfaces of THH Pt NCs are extremely active for the electrooxidation of small organic molecules but they also readily accommodate the dissociative chemisorption of such species, resulting in poisoning by strongly adsorbed CO. Formic acid oxidation is an ideal reaction for studying the balance between these competing catalyst characteristics, since it can proceed by either a direct or a CO mediated pathway. Herein, we describe electrochemical and in situ FTIR spectroscopic investigations of formic acid electrooxidation at both clean and Au adatom decorated THH Pt NC surfaces. The Au decoration leads to higher catalytic currents and enhanced CO(2) production in the low potential range. As the CO oxidation behaviour of the catalyst is not improved by the presence of the Au, it is likely that the role of the Au is to promote the direct pathway. Beyond their fundamental importance, these results are significant in the development of stable, poison resistant anodic electrocatalysts for direct formic acid fuel cells.
authors.affiliation: State Key Lab of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
authors.forename: Hai-Xia
authors.initials: HX
authors.lastname: Liu
authors.forename: Na
authors.initials: N
authors.lastname: Tian
authors.forename: Michael P
authors.initials: MP
authors.lastname: Brandon
authors.forename: Jun
authors.initials: J
authors.lastname: Pei
authors.forename: Zhi-Chao
authors.initials: ZC
authors.lastname: Huangfu
authors.forename: Chi
authors.initials: C
authors.lastname: Zhan
authors.forename: Zhi-You
authors.initials: ZY
authors.lastname: Zhou
authors.forename: Christopher
authors.initials: C
authors.lastname: Hardacre
authors.forename: Wen-Feng
authors.initials: WF
authors.lastname: Lin
authors.forename: Shi-Gang
authors.initials: SG
authors.lastname: Sun