Tb promoted Pd/C catalysts for the electrooxidation of ethanol in alkaline media Son Truong Nguyen a , Delphine Si Ling Tan a , Jong-Min Lee a , Siew Hwa Chan b , Jing Yuan Wang c , Xin Wang a, * a School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 639798, Singapore b School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore c Residues and Resource Reclamation Centre, Nanyang Technological University, Singapore article info Article history: Received 11 March 2011 Received in revised form 6 May 2011 Accepted 8 May 2011 Available online 12 June 2011 Keywords: Ethanol oxidation Palladium Terbium Rare-earth Alkaline fuel cell Direct ethanol fuel cell abstract Various PdeTb/C electrocatalysts with different Pd/Tb ratios were synthesized and tested for ethanol oxidation in alkaline media. The structure and morphology of the nano- catalysts were investigated using X-ray diffraction and transmission electron microscopy. The data showed that face-centered cubic structures were formed for all the PdeTb/C catalysts and a well dispersion of nanoparticles on carbon black was observed. The elec- trocatalytic properties of the catalysts for ethanol oxidation in alkaline solution were tested by cyclic voltammetry, linear sweep voltammetry and chronoamperometry tech- niques. It was found that PdeTb/C catalysts have higher activity and durability for ethanol oxidation than Pd/C. This may be attributed to the promotion effect of Tb on OH  adsorption. The highest performance was observed for 10%Pde2%Tb/C in terms of the highest activity, stability and lowest activation energy for ethanol oxidation. Copyright ª 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. 1. Introduction The world’s demand for energy has increased dramatically over the last few decades, and will continue to do so. Demand from developed nations will remain high while more energy, on a massive scale, will be required by developing nations to fuel their economic growth. Meeting this global demand will be a difficult enough task, even without the necessity of dealing with environmental issues such as climate change. Therefore, it is urgent to find alternative energy sources and perhaps unconventional way of energy conversion with much improved energy efficiency. Fuel cell, which is able to convert chemical energy into electrical energy with high efficiency and very low emission, has proved to be a promising solution for this issue. Among different kinds of fuel cells, direct alcohol fuel cell (DAFC) has attracted the attention of many researchers for small portable power applications. Methanol has been widely studied as the fuel for DAFC, but it is toxic to human beings. Hence, ethanol, which possesses a higher energy density and is easy to be mass-produced by fermentation, has increasingly attracted more attention [1e6]. To-date, platinum (Pt) has been commonly used as the cata- lyst for alcohol oxidation in proton exchange membrane fuel cells and this largely contributes to the expensive cost of fuel cell. In alkaline medium, less corrosive environment and improved kinetics of alcohol oxidation reactions offer the * Corresponding author. Fax: þ65 6794 7553. E-mail address: WangXin@ntu.edu.sg (X. Wang). Available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 36 (2011) 9645 e9652 0360-3199/$ e see front matter Copyright ª 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.ijhydene.2011.05.049