Du Yujie, Zhang Kaiyang, Yao Rui, Wu Yun, Zhao Qiang, Li Jinping, Liu Guang
Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan, Shanxi 030024, PR China.
Dalton Trans. 2022 Nov 21;51(45):17361-17367. doi: 10.1039/d2dt02781j.
Designing highly active and durable oxygen evolution reaction (OER) electrocatalysts is indispensable for promoting the sluggish reaction kinetics of OER to achieve low overpotential. RuO is one of the representative oxygen evolution electrocatalysts in acid electrolytes, but it still faces the problem of poor stability. Herein, RuO nanocrystal with an ultra-small size of approximately 3.5 nm loaded on N-doped hierarchical porous carbon (NHC) is successfully synthesized by RuCl dipping, followed by an annealing process. It is found that NHC is assembled of porous nanosheets with a high specific surface area (BET up to 2107 m g), which could provide more active sites for RuO loading and enable decorated catalysts to be effectively utilized. Combining the advantages of porous NHC and the high electrocatalytic activity of RuO, the optimized electrocatalyst RuO/NHC achieves a low overpotential of 186 mV at 10 mA cm for acidic water oxidation with a Tafel slope as low as 60 mV dec and maintains excellent long-term stability throughout the 27 h chronopotentiometry test in 0.5 M HSO. The elevated acidic OER activity and stability can be attributed to the diminutive size, abundant oxygen vacancies, and enlarged electrochemically active surface area of RuO/NHC. This work could provide opportunities to explore efficient anodic electrocatalysts in acidic media.
设计高活性和耐用的析氧反应（OER）电催化剂对于促进OER缓慢的反应动力学以实现低过电位至关重要。RuO是酸性电解质中典型的析氧电催化剂之一，但仍面临稳定性差的问题。在此，通过RuCl浸渍，随后进行退火处理，成功合成了负载在N掺杂分级多孔碳（NHC）上的尺寸约为3.5 nm的超小RuO纳米晶体。研究发现，NHC由具有高比表面积（BET高达2107 m²/g）的多孔纳米片组装而成，可为RuO负载提供更多活性位点，并使修饰后的催化剂得到有效利用。结合多孔NHC的优势和RuO的高电催化活性，优化后的电催化剂RuO/NHC在10 mA/cm²的酸性水氧化中实现了186 mV的低过电位，塔菲尔斜率低至60 mV/dec，并在0.5 M H₂SO₄中进行的27小时计时电位测试中保持了优异的长期稳定性。酸性OER活性和稳定性的提高可归因于RuO/NHC的小尺寸、丰富的氧空位和增大的电化学活性表面积。这项工作可为探索酸性介质中的高效阳极电催化剂提供机会。
