Improving the hydrogen oxidation reaction rate by promotion of hydroxyl adsorption
Improving the hydrogen oxidation reaction rate by promotion of hydroxyl adsorption
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DOI：
10.1038/nchem.1574
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发表时间：
2013-04-01
期刊：
影响因子：
21.8
通讯作者：
Markovic, Nenad M.
中科院分区：
文献类型：
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作者：
Strmcnik, Dusan;Uchimura, Masanobu;Markovic, Nenad M.
作为化石燃料技术的可行替代品，氢能源的发展彻底改变了使用燃料电池的清洁能源生产。然而，迄今为止，碱性环境中氢氧化反应（HOR）的缓慢速率阻碍了碱性燃料电池系统的进步。在这里，我们通过研究碱性环境中 HOR 活性的趋势来解决这个问题。我们证明，与最先进的铂催化剂相比，它的性能可以提高五倍以上。材料（Ir 和 Pt-0.1 Ru-0.9）的活性最大，且 H-2 吸附/解离和羟基物质 (OHad) 吸附所需的活性位点之间具有最佳平衡。我们提出 Ir（缺陷）和 PtRu 材料（Ru 原子）电极上更多的亲氧位点有利于 OHad 物质的吸附。然后它们与吸附在更惰性表面位点上的氢中间体（H-ad）反应。
The development of hydrogen-based energy sources as viable alternatives to fossil-fuel technologies has revolutionized clean energy production using fuel cells. However, to date, the slow rate of the hydrogen oxidation reaction (HOR) in alkaline environments has hindered advances in alkaline fuel cell systems. Here, we address this by studying the trends in the activity of the HOR in alkaline environments. We demonstrate that it can be enhanced more than fivefold compared to state-of-the-art platinum catalysts. The maximum activity is found for materials (Ir and Pt-0.1 Ru-0.9) with an optimal balance between the active sites that are required for the adsorption/dissociation of H-2 and for the adsorption of hydroxyl species (OHad). We propose that the more oxophilic sites on Ir (defects) and PtRu material (Ru atoms) electrodes facilitate the adsorption of OHad species. Those then react with the hydrogen intermediates (H-ad) that are adsorbed on more noble surface sites.