Shaped palladium nanoparticles (PdNPs) have the potential to be selective catalysts. Unfortunately, there are some obstacles that hinder their use in heterogeneous catalysis, e.g., nanoparticles are difficult to remove from solution after a reaction. Attaching nanoparticles to a support addresses this issue. However, it is typically a two-step process, and the time and energy involved circumvents the energy saving goals of catalysis. Additionally, shaped nanoparticle synthesis usually occurs at high temperatures, which is also counterproductive. We have developed a method to create shaped PdNPs directly on porous carbon microspheres using coffee as a room temperature reductant. By adding ions, such as Br- and Fe3+, the stability of different crystal faces are altered, which results in deviations from spherical nanoparticles. Other additives, such as ethylene glycol, are added to change the reaction kinetics. Analysis by SEM indicates that our synthesized PdNPs are roughly 50 nm in dimension. The size, shape, and distribution of nanoparticles varied based on the ratios of the reactants in the synthetic process. The concentration of tin chloride plays a large role in the size and distribution of the particles. Thermogravimetric analysis and SEM were used to illustrate this effect. Different ratios of reactants and adjustments in the synthetic process are being tested in hopes of maximizing the percentage of shaped particles. If successful, our PdNPs show promise in being effective, environmentally friendly selective catalysts.

Shaped palladium nanoparticle synthesis on carbon substrates

249th National Meeting (2015)

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