Pt-Ni Aerogels as Unsupported Electrocatalysts for the Oxygen Reduction Reaction
Pt-Ni Aerogels as Unsupported Electrocatalysts for the Oxygen Reduction Reaction
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DOI：
10.1149/2.0251609jes
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发表时间：
2016-01-01
影响因子：
3.9
通讯作者：
Schmidt, Thomas J.
中科院分区：
文献类型：
--
作者：
Henning, Sebastian;Kuehn, Laura;Schmidt, Thomas J.
聚合物电解质燃料电池(PEFCs)的商业可行性取决于具有更高活性和/或更低铂含量以及更高稳定性的铂基O-2还原催化剂的开发。为了满足这些要求，在水溶液中通过简单的一步还原和凝胶形成过程合成了以纳米链状网络(气凝胶)形式相互连接的无载体双金属铂镍纳米颗粒(NPs)。用X-射线吸收光谱对新合成路线的产物进行了表征，以确定材料的结构。通过电化学实验，我们对合成的气凝胶和同等材料在酸作用下的表面组成进行了探讨，结果表明，在Ni-浓度较大的气凝胶中存在Ni-(Hydr)氧化物侧相。无论初始表面组成如何，与商用铂碳催化剂相比，铂镍气凝胶的比表面ORR活性提高了近3倍，达到了在汽车PEFC中应用的质量比要求。(C)作者(S)2016年。由ECS出版。版权所有。
The commercial feasibility of polymer electrolyte fuel cells (PEFCs) passes by the development of Pt-based, O-2-reduction catalysts with greater activities and/or lower Pt-contents, as well as an improved stability. In an effort to tackle these requirements, unsupported bimetallic Pt-Ni nanoparticles (NPs) interconnected in the shape of nanochain networks (aerogels) were synthesized using a simple one-step reduction and gel formation process in aqueous solution. The products of this novel synthetic route were characterized by X-ray absorption spectroscopy to elucidate the materials' structure. Using electrochemical experiments, we probed the surface composition of the as-synthesized aerogels and of equivalent materials exposed to acid, and concluded that a Ni-(hydr) oxide side phase is present in the aerogel with a larger Ni-concentration. Regardless of this initial surface composition, the Pt-Ni aerogels feature a approximate to 3-fold increase of surface-specific ORR activity when compared to a commercial platinum-on-carbon catalyst, reaching the mass-specific requirement for application in automotive PEFCs. (C) The Author(s) 2016. Published by ECS. All rights reserved.