Generation of silver/palladium nanoparticles by liquid flame spray

Ag-Pd alloy nanoparticles have been generated from silver and palladium nitrate precursors using a high temperature aerosol method, the liquid flame spray (LFS) process. In the LFS process, a spray aerosol of precursor liquid is introduced into a high-temperature H-2-O-2 flame. The primary micron-sized spray droplets evaporate in the flame, and the final particulate product is a result of the nucleation of the pure metal vapors shortly after the flame. In the study, three Ag-Pd molar ratios-10:90, 50:50, and 90:10-were used in the precursor. As a result of the synthesis, metal alloy nanoparticles with practically the same concentration ratios, correspondingly, were produced with the method. In the experiments, metal mass flow rates of 0.01-0.8 g/min were covered. The size of the particles was determined to be in the range of 10-50 nm by aerosol instrumentation. The particles were spherical and slightly agglomerated. It was concluded that the particle size can be controlled via the total precursor mass flow rate, and the composition can be controlled by the molar ratio of Ag and Pd compounds in the precursor liquid.