Journal of Physics and Chemistry of Solids 69 (2008) 1284–1287 Electrosynthesis of mesoporous Pt–Au alloy electrode for direct methanol fuel cell Eun-Kyung Park, Jin-Kyu Lee, Young-Soo Kim, Gil-Pyo Kim, Sung-Hyeon Baeck Department of Chemical Engineering, Regional Innovation Center for Environmental Technology of Thermal Plasma (ETTP), Inha University, Incheon 402-751, Republic of Korea Received 29 June 2007; accepted 14 September 2007 Abstract Mesoporous Pt–Au alloy films were successfully fabricated on ITO-coated glass from an aqueous mixture of H 2 PtCl 6 and HAuCl 4 by electrodeposition method using proper amount of poly(ethylene glycol)–poly(propylene glycol)–poly(ethylene glycol) (P123) as a templating agent. For comparison, nonporous Pt and mesoporous Pt were electrodeposited. Crystallinity of synthesized film was investigated by X-ray diffraction (XRD) analysis, and film composition was determined by energy dispersive X-ray spectro- scopy (EDS). Scanning electron microscopy (SEM) was utilized to examine surface morphology and it was observed that the addition of P123 affected the particle growth, resulting in a significant change of surface morphology. The mesoporous structure was confirmed by transmission electron microscopy (TEM), and it was concluded that the formation of mesoporous structure strongly depended on electrodeposition conditions, such as deposition voltage, deposition time, temperature and P123 concen- tration. Compared with pure Pt electrodes, mesoporous Pt–Au film showed higher catalytic activities and stability for methanol oxidation. r 2007 Elsevier Ltd. All rights reserved. Keywords: A. Alloys; A. Nanostructures; D. Electrochemical properties 1. Introduction Although methanol oxidation has been strongly studied for methanol–air fuel cells (DMFCs), which have attracted great attention as a power source for portable electronic devices, the anodic activities of commercial catalysts are still low [1,2]. Pt has been well known as the most effective catalyst for methanol oxidation, but it is very expensive and is easily poisoned by reaction intermediates (CH x O), resulting in serious deactivation [3–5]. To overcome these disadvantages, synthesis of Pt-alloy electrode and fabrication of nanostructured electrode have been proposed. Although Pt-alloys have been known to be effective in increasing catalytic activity, the electrochemical instability is a main problem. For example, Pt–Ru is electrochemically unstable due to the dissolution of Ru at elevated temperature and potential [6–9]. Mesoporous electrodes have been of great interest because of their high surface area and short diffusion length of both ion and electron. In general, mesoporous electrode has been synthesized by various methods, inclu- ding sol–gel method, sputtering, and pyrolysis method. Electrodeposition method has been recently suggested for the fabrication of mesoporous electrode, and electroactive electrode can be directly synthesized by this method. Moreover, mesoporous structure can be fabricated using a small amount of templating agent because it utilizes the micelles which are formed on the surface of working electrode by electric potential [10,11]. In this study, we synthesized mesoporous Pt–Au alloy film by electrochemical method using P123 as a templating agent, and investigated catalytic activity for methanol ARTICLE IN PRESS www.elsevier.com/locate/jpcs 0022-3697/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.jpcs.2007.09.009 Corresponding author. Tel.: +82 32 860 7474; fax: +82 32 872 0959. E-mail address: shbaeck@inha.ac.kr (S.-H. Baeck).