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Probing Size and Substrate Effects on the Hydrogen Evolution Reaction by Single Isolated Pt Atoms, Atomic Clusters, and Nanoparticles.
Zhou, Min; Bao, Shujuan; Bard, Allen J.
Affiliation
  • Zhou M; Center for Electrochemistry, Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712 , United States.
  • Bao S; Center for Electrochemistry, Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712 , United States.
  • Bard AJ; Center for Electrochemistry, Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712 , United States.
J Am Chem Soc ; 141(18): 7327-7332, 2019 05 08.
Article in En | MEDLINE | ID: mdl-31017772
We report the catalytic activity of a single, isolated Pt deposit on Bi and Pb supports to probe the size and substrate effects on the electrochemical hydrogen evolution reaction (HER). Deposits were made electrolytically by an atom-by-atom method in a controlled plating; we prepared an individual Pt deposit on Bi and Pb ultramicroelectrodes (UMEs) such as a single isolated atom, clusters containing one to five Pt atoms, and nanoparticles to about 10 nm radius. A steady-state voltammogram on the single Pt deposits is observed by electrocatalytic amplification of the HER, with a negligible contribution by the HER at the substrate UME. A single Pt atom can act as an electrode for the HER, showing a diffusion-limiting current plateau in the voltammogram that can be used to estimate the radius of a single deposit. We simulated the voltammograms of the individual deposits, assuming the Volmer step of the HER is appropriate for a Pt cluster deposit, to obtain kinetic parameters for each deposit. The HER kinetics increases as the particle radius increases from ∼0.2 to ∼4 nm for Bi and Pb substrates and then reaches a limiting plateau. The limiting kinetics on the Bi substrate approaches that of bulk Pt while that on the Pb substrate is much smaller.
Subject(s)

Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Platinum / Metal Nanoparticles / Electrochemical Techniques / Hydrogen Language: En Journal: J Am Chem Soc Year: 2019 Document type: Article Affiliation country: Country of publication:

Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Platinum / Metal Nanoparticles / Electrochemical Techniques / Hydrogen Language: En Journal: J Am Chem Soc Year: 2019 Document type: Article Affiliation country: Country of publication: