Abstract Pt based materials are the most efficient electrocatalysts for the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) in fuel cells. Maximizing the utilization of Pt based materials by modulating their morphologies to expose more active sites is a fundamental objective for the practical application of fuel cells. Herein, we report a new class of hierarchically skeletal Pt-Ni nanocrystals (HSNs) with a multi-layered structure, prepared by an inorganic acid-induced solvothermal method. The addition of H2SO4 to the synthetic protocol provides a critical trigger for the successful growth of Pt-Ni nanocrystals with the desired structure. The Pt-Ni HSNs synthesized by this method exhibit enhanced mass activity of 1.25 A mgpt−1 at 0.9 V (versus the reversible hydrogen electrode) towards ORR in 0.1-M HClO4, which is superior to that of Pt-Ni multi-branched nanocrystals obtained by the same method in the absence of inorganic acid; it is additionally 8.9-fold higher than that of the commercial Pt/C catalyst. Meanwhile, it displays enhanced stability, with only 21.6% mass activity loss after 10,000 cycles (0.6–1.0 V) for ORR. Furthermore, the Pt-Ni HSNs show enhanced activity and anti-toxic ability in CO for MOR. The superb activity of the Pt-Ni HSNs for ORR and MOR is fully attributed to an extensively exposed electrochemical surface area and high intrinsic activity, induced by strain effects, provided by the unique hierarchically skeletal alloy structure. The novel open and hierarchical structure of Pt-Ni alloy provides a promising approach for significant improvements of the activity of Pt based alloy electrocatalysts.

中文翻译：

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用于高效氧还原和甲醇氧化反应的分层骨架多层 Pt-Ni 纳米晶体

摘要 Pt 基材料是燃料电池中氧还原反应 (ORR) 和甲醇氧化反应 (MOR) 最有效的电催化剂。通过调节 Pt 基材料的形态以暴露更多活性位点来最大限度地利用 Pt 基材料是燃料电池实际应用的基本目标。在此，我们报告了一类新的具有多层结构的分层骨架 Pt-Ni 纳米晶体 (HSN)，其通过无机酸诱导的溶剂热法制备。在合成方案中加入 H2SO4 为成功生长具有所需结构的 Pt-Ni 纳米晶体提供了关键触发条件。通过这种方法合成的 Pt-Ni HSNs 在 0.9 V（相对于可逆氢电极）对 0.1-M HClO4 中的 ORR 表现出增强的质量活性 1.25 A mgpt-1，优于相同方法在无无机酸存在下获得的Pt-Ni多支化纳米晶；此外，它比商业 Pt/C 催化剂高 8.9 倍。同时，它显示出更高的稳定性，ORR 在 10,000 次循环 (0.6-1.0 V) 后仅损失 21.6% 的质量活性。此外，Pt-Ni HSNs 在 CO 中对 MOR 显示出增强的活性和抗毒能力。Pt-Ni HSN 对 ORR 和 MOR 的出色活性完全归因于广泛暴露的电化学表面积和由应变效应引起的高本征活性，这是由独特的分层骨架合金结构提供的。Pt-Ni 合金的新型开放和分级结构为显着提高 Pt 基合金电催化剂的活性提供了一种有前景的方法。