College of Chemistry and Materials Science, Anhui Key Laboratory of Functional Molecular Solids, Anhui Normal University, Wuhu 241000, P. R. China.
Langmuir. 2012 May 8;28(18):7168-73. doi: 10.1021/la300813z. Epub 2012 Apr 23.
It is a known fact that Pd-based bimetallic nanostructures possess unique properties and excellent catalytic performance. In this work, the Au-Pd alloy and core-shell nanostructures have been prepared by a simple one-pot hydrothermal coreduction route, and their formation process and mechanism are discussed in detail. A reducing capacity-induced controlled reducing mechanism is proposed for the formation process of Au-Pd bimetallic nanostructures. CTAB plays a key role in the formation of alloy Au-Pd nanostructures. When CTAB is absent, the products are typical core-shell nanostructures. Moreover, the as-prepared nanostructures exhibit excellent electrocatalytic ORR performance in alkaline media, especially for Au-Pd alloy nanostructures. The overpotential of oxygen reduction gets reduced significantly, and the peak potential is positive-shifted by 44 and 34 mV in comparison with the core-shell ones and Pd/C catalyst, respectively. Thus, the controllable preparation and excellent electrocatalytic properties will make them become a potentially cheaper Pd-based cathodic electrocatalyst for DAFCs in alkaline media.
众所周知，钯基双金属纳米结构具有独特的性质和优异的催化性能。在这项工作中，通过简单的一锅水热共还原法制备了 Au-Pd 合金和核壳纳米结构，并详细讨论了其形成过程和机制。提出了一种还原能力诱导的可控还原机制来解释 Au-Pd 双金属纳米结构的形成过程。CTAB 在合金 Au-Pd 纳米结构的形成中起着关键作用。当 CTAB 不存在时，产物是典型的核壳纳米结构。此外，所制备的纳米结构在碱性介质中表现出优异的电催化 ORR 性能，特别是对于 Au-Pd 合金纳米结构。氧还原的过电势显著降低，与核壳结构和 Pd/C 催化剂相比，峰值电势分别正向移动了 44 和 34 mV。因此，可控的制备和优异的电催化性能将使它们成为碱性介质中用于 DAFC 的潜在更廉价的 Pd 基阴极电催化剂。
