Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)
Rickey Terrell - University of Cincinnati
To decrease costs of fuel cell fabrication, it is necessary to minimize precious metal loadings. A novel solution is dispersing platinum catalysts in nanoparticle form. The synthesis approach used to make these nanoparticles is directly related to their morphology and, as a consequence, their catalytic activity. Therefore, it is imperative to have characterization methods to observe the dynamic evolution of the chemical structures produced during the synthesis process. Previous structural data was acquired using EXAFS and Mössbauer Spectroscopy; however, a more robust method is nuclear magnetic resonance spectroscopy (NMR). In addition to being more readily accessible, NMR provides a greater flexibility of testing parameters and analysis tools. To confirm its utility in this field, experimental 195-Pt NMR data was collected and compared to data acquired using alternative characterization methods. Nanoparticle precursor solutions were synthesized containing three previously confirmed complexes: [Pt(SnCl3)]5-, [PtCl2(SnCl3)2]2-, and [PtCl3(SnCl3)]2-. All NMR data was collected using a Bruker 500 MHz spectrometer. The identity of the complexes in the solution were confirmed using both literature chemical shift values and theoretical NMR parameter calculations. Both experimental and theoretical 195-Pt chemical shift data aligns with past studies of platinum complexes in precursor nanoparticle solutions. With this new characterization method, NMR will provide a better understanding of nanoparticle synthesis mechanisms leading to the development of more catalytically active nanoparticles for fuel cell applications. Short term future work will include investigation of different platinum alloy nanoparticle synthesis to identify the relationship between alloy metal identity and nanoparticle properties. This research was funded by the National Science Foundation.
Funder Acknowledgement(s): National Science Foundation
Faculty Advisor: Dr. Anastasios Angelopoulos, firstname.lastname@example.org
Role: I completely developed and tested this new structural characterization method. I synthesized all samples, collected and analyzed all experimental NMR data, and completed all theoretical DFT calculations.