Abstract The development of highly efficient and durable catalysts for production and storage of clean energy remains a formidable challenge. Herein, a bifunctional electrocatalyst composed of ultrasmall ruthenium nanoparticles confined within a hollow nitrogen-doped carbon spheres (Ru/HNCS) was designed and synthesized through the pyrolysis of Ru3+ coordinated polydopamine layers. The as-synthesized Ru/HNCS with Ru content even below 0.1 wt% exhibited excellent catalytic activities towards both hydrogen production and oxygen reduction. When catalyzing hydrogen evolution reaction, a low overpotential of 39 mV was sufficiently to achieve the current density of 10 mA cm−2 in acidic media and the corresponding Tafel slope was only 30 mV dec−1. Furthermore, Ru/HNCS also exhibited outstanding oxygen reduction reaction activity with a half-potential of 0.72 V and an onset potential of 0.83 V, as well as high stability and palmary anti-poisoning capability for methanol in basic electrolyte. This Ru/HNCS might be a promising alternative to Pt-based electrocatalysts in energy conversion and storage.

中文翻译：

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一种用于析氢和氧还原反应的高效钌基双电催化剂

摘要 开发高效、耐用的清洁能源生产和储存催化剂仍然是一项艰巨的挑战。在此，通过Ru3+配位聚多巴胺层的热解，设计并合成了一种双功能电催化剂，该催化剂由限制在空心氮掺杂碳球（Ru/HNCS）内的超小钌纳米颗粒组成。Ru含量甚至低于0.1wt%的合成的Ru/HNCS对产氢和氧还原都表现出优异的催化活性。在催化析氢反应时，39 mV 的低过电位足以在酸性介质中实现 10 mA cm-2 的电流密度，相应的 Tafel 斜率仅为 30 mV dec-1。此外，Ru/HNCS 还表现出优异的氧还原反应活性，半电位为 0.72 V，起始电位为 0.83 V，对碱性电解质中的甲醇具有高稳定性和抗棕榈中毒能力。这种 Ru/HNCS 可能是 Pt 基电催化剂在能量转换和存储方面的有前途的替代品。