Abstract

This paper reports a study on the pH effects on the PtRu nanoparticles synthesized in a polyol process that were deposited on carbon nanotubes (CNTs) by reducing metal salts using ethylene glycol at various pHs. It was found that the nanoparticle size, composition, and catalytic activity all were sensitive to pH. the nanoparticles decreased in size as the preparation pH increased from 1.6 to 10.0, with the largest size at 2.47 nm and the smallest at 1.13 nm. an exception was found for pH at 0.7, which resulted in an average size of only 1.01 nm. Preparation pH was found to affect polyol reaction mechanisms, which are believed to be dominated by direct metal reduction at low pH and by both direct metal reduction and hydroxide reduction at high pH. However, at high pH the reactions were limited by hydroxide reductions, and longer reaction durations were needed to fully deposit the metals. to study the pH effect on the electrochemical activity of the catalysts, CO stripping techniques were used to determine peak potentials and active surface areas. Together with cyclic voltammetry in the electro-oxidation of methanol, it was found that the catalyst prepared at pH 8.4 has the best performance. © 2008 Elsevier Ltd. All rights reserved.

Department(s)

Chemical and Biochemical Engineering

Comments

National Science Foundation, Grant -0522931

Keywords and Phrases

Carbon nanotubes; Electrocatalysts; Fuel cells; Methanol oxidation; PtRu

International Standard Serial Number (ISSN)

0013-4686

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Elsevier; International Society of Electrochemistry (ISE), All rights reserved.

Publication Date

01 Jul 2008

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