The development of efficient catalysts for ethanol oxidation in alkaline medium requires a synthetic approach that may prevent the surfactant molecules from being adsorbed at the catalytic sites and decreasing the electrochemical performance of the final direct ethanol fuel cell. Toward this goal, the recently reported surfactant-less Bromide Anion Exchange (BAE) method, appears as a promising route to conveniently aim at preparing PtRh alloys dispersed on carbon substrates. The catalysts prepared herein by the BAE method were characterized physicochemically to obtain structural information on the PtRh/C nanomaterials, their morphology (size and shape), and their chemical and surface composition. Electrochemical behavior and properties of these electrodes were then investigated in a half-cell before the implementation of a direct ethanol fuel cell (DEFC) in a home-made anion exchange membrane Teflon cell. The analysis of the electrolytic solution in the anodic compartment by chromatography revealed that acetate was the major reaction product and the carbonate amount increased with the Rh content in the bimetallic composition. With 2.8–3.6 nm particle sizes, the Pt₅₀Rh₅₀/C catalyst exhibited the highest activity towards the ethanol electrooxidation.

中文翻译：

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铑对直接碱性乙醇燃料电池中铂阳极材料的影响

开发用于碱性介质中乙醇氧化的高效催化剂需要一种合成方法，该方法可以防止表面活性剂分子吸附在催化位点并降低最终直接乙醇燃料电池的电化学性能。为了实现这一目标，最近报道的无表面活性剂溴化物阴离子交换 (BAE) 方法似乎是一种有希望的途径，可以方便地制备分散在碳基材上的 PtRh 合金。本文通过 BAE 方法制备的催化剂进行了物理化学表征，以获得 PtRh/C 纳米材料的结构信息、它们的形态（尺寸和形状）以及它们的化学和表面组成。然后在自制阴离子交换膜 Teflon 电池中实施直接乙醇燃料电池 (DEFC) 之前，在半电池中研究这些电极的电化学行为和特性。通过色谱分析阳极室中的电解液表明醋酸盐是主要的反应产物，并且碳酸盐的数量随着双金属组合物中Rh含量的增加而增加。Pt 粒径为 2.8–3.6 nm₅₀ Rh ₅₀ /C催化剂对乙醇电氧化表现出最高的活性。