Bimetallic nanoparticles with well-defined, faceted surfaces are powerful models for testing predictions from fundamental surface science studies under conditions of catalytic turnover. In particular, dilute bimetallic nanoparticles, whose surface is composed of a more reactive metal dispersed in a less reactive metal, hold particular promise for achieving selectivity in challenging chemical transformations. However, the controlled, deliberate synthesis of the materials required to probe these hypotheses is non-trivial because materials with differing reactivity in their metallic forms also have metal ion precursors with differing reduction potentials and reduction kinetics. To address this challenge, our lab has developed a versatile toolbox of techniques to control the relative reduction kinetics of metal ion precursors with differing chemistry. These tools include (1) halide-assisted metal ion reduction, where micromolar concentrations of halide ions are employed to differentially control metal ion reduction rates; (2) plasmon-mediated metal ion reduction, where visible light illumination enables the reduction of a poorly-plasmonic metal onto a plasmonic core; and (3) sequential co-reduction, where careful choice of metal ion precursors results in the significantly faster reduction of one of a pair of metals, and this metal both controls nanoparticle shape and catalyzes the reduction of the second metal. These approaches have enabled the synthesis of nanostructures with previously unachievable architectures and a range of dilute bimetallic compositions, including gold-palladium, palladium-copper, and silver-platinum.

Differential control of metal ion reduction kinetics: Building a toolbox for the tailorable synthesis of dilute bimetallic nanoparticles

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.