Ultra-small and monodispersed Pt nanoparticles (NPs) have been successfully synthesized in polymer electrolyte membrane fuel cells. The process normally involves the use of capping agents, organic species, templates, and substrates and is thus complex. Hence, obtaining Pt NPs with a clean surface is challenging. In this study, a method for preparing stable and highly dispersed Pt NPs with clean surfaces is proposed. The method involves the use of a modified Na3C6H5O7 reduction process assisted by NaNO3 stabilization. The specific complexations of NO2- ions possibly alter the reaction kinetics and lower the growth rate of Pt NPs by retarding the reduction reaction. The optimized Pt/carbon nanotube (CNT) catalysts exhibit high mass activity and moderate activity decay after 10,000 times of potential cycling compared with commercially available Pt/C catalysts. Then, membrane electrode assemblies based on the resultant catalysts are characterized. The cell performance of 744 mW cm-2 (maximum power density) is achieved after the optimized Pt/CNT catalysts are used in carbon black.

中文翻译：

---

通过改性柠檬酸盐还原制备稳定而活性的Pt胶体以及无机添加剂的机理分析。

在聚合物电解质膜燃料电池中已成功合成了超小且单分散的Pt纳米颗粒（NPs）。该过程通常涉及使用封端剂，有机物质，模板和底物，因此很复杂。因此，获得具有清洁表面的Pt NP具有挑战性。在这项研究中，提出了一种制备具有清洁表面的稳定且高度分散的Pt NP的方法。该方法涉及使用经过改良的Na3C6H5O7还原工艺，并辅以NaNO3稳定化处理。NO 2-离子的特定络合可能通过延迟还原反应而改变反应动力学并降低Pt NPs的生长速率。经过优化的Pt /碳纳米管（CNT）催化剂在10，与市售Pt / C催化剂相比，潜在循环的000倍。然后，表征基于所得催化剂的膜电极组件。在炭黑中使用优化的Pt / CNT催化剂后，电池性能达到744 mW cm-2（最大功率密度）。