Characterization of platinum nanoparticles for fuel cell applications by single particle inductively coupled plasma mass spectrometry

Ram P Lamsal; Aaron Hineman; Chady Stephan; Sadaf Tahmasebi; Stève Baranton; Christophe Coutanceau; Gregory Jerkiewicz; Diane Beauchemin

doi:10.1016/j.aca.2020.09.021

Characterization of platinum nanoparticles for fuel cell applications by single particle inductively coupled plasma mass spectrometry

Anal Chim Acta. 2020 Dec 1:1139:36-41. doi: 10.1016/j.aca.2020.09.021. Epub 2020 Sep 15.

Authors

Ram P Lamsal¹, Aaron Hineman², Chady Stephan², Sadaf Tahmasebi¹, Stève Baranton³, Christophe Coutanceau³, Gregory Jerkiewicz⁴, Diane Beauchemin⁵

Affiliations

¹ Queen's University, Department of Chemistry, 90 Bader Lane, Kingston, ON, K7L 3N6, Canada.
² PerkinElmer Canada, 501 Rowntree Dairy Rd, Unit 6, Woodbridge, ON, L4L 8H1, Canada.
³ Université de Poitiers IC2MP, Equipe "Catalyse et Milieux Non-Conventionnels", 4 Rue Michel Brunet, B27, TSA 51106, 86073, Poitiers cedex 9, France.
⁴ Queen's University, Department of Chemistry, 90 Bader Lane, Kingston, ON, K7L 3N6, Canada. Electronic address: gregory.jerkiewicz@queensu.ca.
⁵ Queen's University, Department of Chemistry, 90 Bader Lane, Kingston, ON, K7L 3N6, Canada. Electronic address: diane.beauchemin@queensu.ca.

PMID: 33190707
DOI: 10.1016/j.aca.2020.09.021

Abstract

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.

Keywords: Particle calibration; Particle size measurement; Platinum nanoparticles; Single particle inductively coupled plasma mass spectrometry; Solution calibration; Transmission electron microscopy.