Synthesis and Electrochemical Study of Antimony-Doped Tin Oxide Supported RuSe Catalysts for Oxygen Reduction Reaction Souradip Malkhandi & Yan Yangang & Vineet Rao & Andreas Bund & Ulrich Stimming Published online: 8 January 2011 # Springer 2011 Abstract In this work, we discuss the results at RuSe catalysts on antimony-doped tin oxide support on the oxygen reduction reaction. The antimony doped-tin oxide support was synthesized using wet chemical method, and RuSe nanoparticle catalysts were synthesized on this support using ruthenium carbonyl precursor with Se powder. The synthesized catalyst was characterized using XRD and EDX and investigated for oxygen reduction reaction using the rotating disk electrode. Keywords Antimony tin oxide . Oxygen reduction . RuSe . Direct methanol fuel cell The direct methanol fuel cell (DMFC) has several advantages over hydrogen fuel cell; however, some inherent limitations of the DMFC make it less efficient. One of the major weaknesses of DMFC is the crossover of methanol from the anode to the cathode through the membrane, which leads to loss of fuel and inferior oxygen reduction reaction (ORR) performance [1]. The methanol crossover problem can be minimized using methanol tolerant ORR catalysts and low methanol perme- able membranes. Also by operating the fuel cell at elevated temperature the methanol crossover rate can be lowered apart from the improvement of performance. It has been already shown by Savinell [2] that the acid doped polybenzimidazole (PBI) membrane, which shows lower methanol permeability in comparison to Nafion membrane can be used in a DMFC with operating temperature around 200 °C. Despite low methanol permeability in PBI membranes, methanol cross- over problem persists because small amount of methanol is sufficient to deteriorate the performance of the Pt-based ORR catalysts [3]. Savinell has suggested higher Pt loading as a remedy. But higher Pt loading means higher costs. The second issue arising with vapor feed DMFCs is the catalyst support. Usually, the catalyst support is carbon and no carbon supported ORR catalyst is suitable for a stable performance of a PBI-based DMFC at the operating temper- ature of 200 °C, because carbon is prone to corrosion [4]. It has been reported [5] that 40% of mono-layer of carbon can be lost in 24 h operation at 1.2 V RHE in 1 M H 2 SO 4 electrolyte at 80 °C, and the weight loss of carbon is directly proportional to BET-specific surface area [5]. Therefore, the degradation of carbon support in a fuel cell, which is operating at 200 °C is likely to be enormous. As a solution to carbon corrosion and methanol crossover, we have proposed for the first time electronically conducting metal oxide supported RuSe catalysts. RuSe is a well-known methanol tolerant ORR catalyst [6, 7]. As an electronically conducting metal oxide, we used antimony-doped tin oxide, which is inherently protected from further oxidation and already is use as support for catalysts [8]. The RuSe catalyst on antimony- doped tin oxide support can solve two fundamental problems in vapor feed DMFC; the decrease of the ORR activity due to methanol crossover and the corrosion of the carbon support. With these two goals in mind, we present our initial results on RuSe on antimony-doped tin oxide in this letter. The materials used were stannous chloride (Merck), sodium carbonate, antimony chloride (Aldrich), ruthenium carbonyl (Alfa Aesar), selenium (Alfa Aesar), o-xylene (Merck), sulfuric acid 96% (Suprapure Merck), di-ethyl- S. Malkhandi (*) : Y. Yangang : V. Rao : A. Bund : U. Stimming (*) Department of Physics E19, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany e-mail: msaura@ph.tum.de U. Stimming e-mail: stimming@ph.tum.de Electrocatal (2011) 2:20–23 DOI 10.1007/s12678-010-0033-y