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Enhanced Reactivity for Hydrogen Reactions at Pt Nanoislands on Au(111)
Author(s) -
Wolfschmidt Holger,
Weingarth Daniel,
Stimming Ulrich
Publication year - 2010
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201000148
Subject(s) - reactivity (psychology) , chemistry , hydrogen , nanotechnology , materials science , photochemistry , organic chemistry , medicine , alternative medicine , pathology
We report high exchange current densities exceeding 1 A cm −2 at Pt nanostructures on Au(111) for hydrogen‐related reactions. Such activity is found at Pt nanoparticles with a coverage of less than 10 % of a monolayer on Au(111) and on single Pt particles deposited on Au(111). Potential pulse technique as well as micropolarization curves with overpotentials of ±10 mV were used in the case of extended nanostructured surfaces to determine the activity. Single Pt particles were investigated in an in situ electrochemical scanning tunneling microscope setup using the STM tip as local sensor. The reactivity obtained on Pt nanostructured Au(111) towards hydrogen reactions were subsidized by single particle reactivity measurements. The specific activity of platinum is enhanced by more than a factor of 1000 as compared to a Pt(111) single crystal. Aspects that may explain this enhancement such as an involvement of the substrate, highly reactive defect sites and enhanced mass transport are discussed.