(458b) Effect of Pd Precursor Salt Type and Temperature on Synthesizing Five-Fold Pentagonal Pd Nanorods Using L-Ascorbic Acid in Segmented Millifluidic Flow Reactors (SMFRs)

L-ascorbic acid is a green reducing agent that has successfully demonstrated the ability to synthesize pentagonal Pd nanorods using Na₂PdCl₄ as the metal precursor in the segmented millifluidic flow reactors (SMFRs)¹. Oxidative etching that is undesirable for formation of Pd nanorods is minimized in the SMFR by restricting presence of air in the reaction mixture thereby limiting air in the reaction mixture². The presence of chloride ions originating from the Pd precursors such as Na₂PdCl₄ and PdCl₂ still causes a degree of oxidative etching that limits the synthesis of Pd nanorods. Alternative Pd precursors such as Na₂PdBr₄ and Pd(NO₃)₂ that do not contain chloride is used to improve the yields of synthesized Pd nanorods. Using Na₂PdBr₄ also had the additional benefit of supplying bromide ions that cap {100} facets of Pd decahedron seeds to promote 1-dimensional growth of nanostructures. The mechanism involved in the synthesis of Pd nanorods with each Pd precursor was identified using Transmission Electron Microscopy (TEM) and kinetic studies conducted via Ultraviolet–visible (UV-vis) spectroscopy. The effect of temperature variation on Pd nanostructure synthesis is examined and used to calculate the activation energy in synthesizing Pd nanorods with each Pd precursor. Reaction conditions are optimized to synthesize the highest possible yield of Pd nanorods. Finally, a filtration procedure is utilized to separate Pd nanostructures other than nanorods synthesized in the SMFR.