State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science , Changchun, Jilin 130022, P. R. China.
University of Science and Technology of China , Hefei, Anhui 230026, P. R. China.
J Am Chem Soc. 2018 Jan 24;140(3):1142-1147. doi: 10.1021/jacs.7b12353. Epub 2018 Jan 16.
Despite the fact that both electrochemical experiments and density functional theory calculations have testified to the superior electrocatalytic activity and CO-poisoning tolerance of platinum-ruthenium (PtRu) alloy nanoparticles toward the methanol oxidation reaction (MOR), the facet-dependent electrocatalytic properties of PtRu nanoparticles are scarcely revealed because it is extremely difficult to synthesize well-defined facets-enclosed PtRu nanocrystals. Herein, we for the first time report a general synthesis of ultrathin PtRu nanocrystals with tunable morphologies (nanowires, nanorods, and nanocubes) through a one-step solvothermal approach and a systematic investigation of the structure-directing effects of different surfactants and the formation mechanism by control experiments and time-dependent studies. In addition, we utilize these {100} and {111} facets-enclosed PtRu nanocrystals as model catalysts to evaluate the electrocatalytic characteristics of the MOR on different facets. Remarkably, {111}-terminated PtRu nanowires exhibit much higher stability and electrocatalytic mass activity toward MOR, which are 2.28 and 4.32 times higher than those of {100}-terminated PtRu nanocubes and commercial Pt/C, respectively, indicating that PtRu {111} facets possess superior methanol oxidation activity and CO-poisoning resistance relative to {100} facets. Our present work provides a series of well-defined PtRu nanocrystals with tunable facets which would be ideal model electrocatalysts for fundamental research in fuel cell electrocatalysis.
尽管电化学实验和密度泛函理论计算都证明了铂-钌（PtRu）合金纳米粒子在甲醇氧化反应（MOR）中具有优越的电催化活性和抗 CO 中毒能力，但由于很难合成具有明确晶面的 PtRu 纳米晶体，因此很少揭示出 PtRu 纳米粒子的晶面依赖性电催化性能。在此，我们首次通过一步溶剂热法报道了一种通用的合成具有可调形态（纳米线、纳米棒和纳米立方体）的超薄 PtRu 纳米晶体的方法，并通过控制实验和时间依赖性研究系统地研究了不同表面活性剂的结构导向作用和形成机制。此外，我们利用这些具有{100}和{111}晶面的 PtRu 纳米晶体作为模型催化剂来评估不同晶面对 MOR 的电催化特性。值得注意的是，{111}端终止的 PtRu 纳米线表现出更高的 MOR 稳定性和电催化质量活性，分别比{100}端终止的 PtRu 纳米立方体和商业 Pt/C 高 2.28 倍和 4.32 倍，表明 PtRu{111}晶面对甲醇氧化具有更高的活性和抗 CO 中毒能力。相对于{100}晶面。我们目前的工作提供了一系列具有可调晶面的明确 PtRu 纳米晶体，它们将是燃料电池电催化基础研究的理想模型电催化剂。
