The most effective utilization of platinum (Pt) in fuel cells is achieved through the use of nanoparticles (NPs) that offer a large electrochemically active surface area. Because the stability of NPs decreases as they become smaller, their size and size distribution must be known in order to optimize the catalysts' durability, while offering high catalytic activity. Single particle inductively coupled plasma mass spectrometry (spICPMS) can quantify the mass of metallic NPs suspended in aqueous medium, which can then be converted into a size if the NPs' shape, density and composition are known. In this study, for the first time, spICPMS was compared to transmission electron microscopy (TEM) for the characterization of 10 nm Pt NPs. After verifying the accurate sizing of commercial Pt NPs with diameters of 30, 50 and 70 nm, spICPMS with solution calibration was applied to laboratory-synthesized 10 nm Pt NPs possessing a near spherical shape and 10 ± 2 nm diameter according to TEM. The same NPs were also analyzed by spICPMS with Pt size calibration using Pt NPs standards. Irrespectively of the calibration strategy, spICPMS measured the entire population of 659 Pt NPs (6-65 nm), while TEM analyzed the 500 Pt NPs that appeared isolated in the field of view (6-18 nm). Analysis of the size distribution histograms revealed that the modal and mean diameters were respectively 10 and 11 ± 2 nm using solution calibration, and 12 and 13 ± 2 nm using particle size calibration. Both of these mean diameters are in agreement with the TEM measurements according to a Student's t-test at the 95% confidence level, demonstrating that spICPMS, with a size detection limit of 6 nm, can accurately quantify 10-nm Pt NPs while at the same time analyzing the entire sample.

中文翻译：

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通过单粒子电感耦合等离子体质谱法表征用于燃料电池的铂纳米粒子

铂 (Pt) 在燃料电池中的最有效利用是通过使用提供大电化学活性表面积的纳米颗粒 (NP) 实现的。由于纳米颗粒的稳定性随着它们变小而降低，因此必须了解它们的尺寸和尺寸分布，以优化催化剂的耐久性，同时提供高催化活性。单粒子电感耦合等离子体质谱 (spICPMS) 可以量化悬浮在水性介质中的金属纳米粒子的质量，如果纳米粒子的形状、密度和组成已知，则可以将其转换为尺寸。在这项研究中，首次将 spICPMS 与透射电子显微镜 (TEM) 进行了比较，以表征 10 nm Pt NP。在验证了直径为 30、50 和 70 nm 的商业 Pt NP 的准确尺寸后，具有溶液校准的 spICPMS 应用于实验室合成的 10 nm Pt NP，根据 TEM，具有近球形形状和 10 ± 2 nm 直径。同样的 NPs 也通过 spICPMS 分析，使用 Pt NPs 标准品进行 Pt 尺寸校准。不管校准策略如何，spICPMS 测量了整个 659 Pt NPs (6-65 nm)，而 TEM 分析了在视场 (6-18 nm) 中出现孤立的 500 Pt NPs。粒度分布直方图的分析表明，使用溶液校准时，模态直径和平均直径分别为 10 和 11 ± 2 nm，使用粒度校准时分别为 12 和 13 ± 2 nm。这两个平均直径都与根据学生 t 检验在 95% 置信水平下的 TEM 测量结果一致，表明 spICPMS 的尺寸检测限为 6 nm，