Raymond Rodgers with M. Sankaran, Department of Chemical Engineering.

Preparation of compositionally-controlled Pt-based nanoparticle alloys via microplasma reduction of aqueous metal ions

Nanoparticle alloys of platinum (Pt) and another metal are desirable for catalytic applications to decrease the loading of the precious metal and alter the physiochemical structure of these materials to enhance their catalytic properties. Examples of potential applications include gas conversion (e.g. CO oxidation), growth of other nanostructures (nanotubes, wires, etc.), and fuel cells. However, there are significant challenges for the synthesis of uniform nanoparticle alloys, in particular controlling their atomic-scale composition and structure. The goal of this project is to develop a new approach to preparing well-defined nanoparticle alloys based on microplasma reduction of aqueous metal ions. In our process, metal salt precursors of Pt and another metal (e.g. Au, Ru, Ir) are dissolved in water and exposed to an atmospheric-pressure microplasma. Electrochemical reduction of metal ions by gas-phase electrons is expected to rapidly form mixed nanoparticle alloys (i.e. no phase segregation of the metals). Our as-grown materials will be characterized by XRD, TEM, and UV-Vis absorbance to confirm and evaluate their size, composition, and crystal structure.