Highly Crystalline Multimetallic Nanoframes with Three-Dimensional Electrocatalytic Surfaces
Highly Crystalline Multimetallic Nanoframes with Three-Dimensional Electrocatalytic Surfaces
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DOI：
10.1126/science.1249061
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发表时间：
2014-03-21
期刊：
影响因子：
56.9
通讯作者：
Stamenkovic, Vojislav R.
中科院分区：
文献类型：
--
作者：
Chen, Chen;Kang, Yijin;Stamenkovic, Vojislav R.
在原子水平上控制结构可以精确有效地调节材料的催化性能，从而提高活性和耐久性。我们通过利用铂镍（Pt-Ni）纳米晶体的结构演变合成了一类高活性和耐用的电催化剂。起始材料，结晶PtNi 3多面体，在溶液中通过内部侵蚀转化为具有提供三维分子可达性的表面的Pt 3 Ni纳米框架。富Pt PtNi 3多面体的边缘保持在最终的Pt 3 Ni纳米框架中。这种开放式骨架结构的内部和外部催化表面都由纳米偏析的Pt-皮肤结构组成，其表现出增强的氧还原反应（ORR）活性。在长时间暴露于反应条件期间，Pt 3 Ni纳米框架催化剂对于该反应（相对于现有技术的铂-碳催化剂）分别实现了质量活性的36倍增强和比活性的22倍增强。
Control of structure at the atomic level can precisely and effectively tune catalytic properties of materials, enabling enhancement in both activity and durability. We synthesized a highly active and durable class of electrocatalysts by exploiting the structural evolution of platinum-nickel (Pt-Ni) bimetallic nanocrystals. The starting material, crystalline PtNi3 polyhedra, transforms in solution by interior erosion into Pt3Ni nanoframes with surfaces that offer three-dimensional molecular accessibility. The edges of the Pt-rich PtNi3 polyhedra are maintained in the final Pt3Ni nanoframes. Both the interior and exterior catalytic surfaces of this open-framework structure are composed of the nanosegregated Pt-skin structure, which exhibits enhanced oxygen reduction reaction (ORR) activity. The Pt3Ni nanoframe catalysts achieved a factor of 36 enhancement in mass activity and a factor of 22 enhancement in specific activity, respectively, for this reaction (relative to state-of-the-art platinum-carbon catalysts) during prolonged exposure to reaction conditions.