The Flat Premixed Droplet Seeded Flame (FPDSF): a versatile method to manufacture nanostructured catalyst materials

OWEN S. FUHR, Farnaz Khosravi, Mahmoud K. Ashour, Francesco Carbone, University of Connecticut

     Abstract Number: 509
     Working Group: Nanoparticles and Materials Synthesis

Abstract
The transition from a fossil-fuel-based economy to one that is sustainable and resilient necessitates the development of technologies accelerating the widespread adoption of renewable energy generation and storage. A key step toward this objective is developing cost-effective methods to manufacture highly active catalyst materials. This study demonstrates the versatility of the Flat Premixed Droplet-Seeded Flame (FPDSF) method in manufacturing metal-based nanostructured catalyst materials for sustainable energy applications from inexpensive precursors. Indeed, the FPDSF allows precise control of the synthesis-environment temperature, stoichiometry, and residence time and yields the desired product material from any liquid soluble precursors being stable in the desired mixing molar proportions. Herein an aqueous solution is made into monodisperse micron-scale droplets by a Vibrating Orifice Aerosol Generator (VOAG) and is mixed with a properly selected nitrogen-diluted blend of gaseous fuels and oxygen. A coupling tube directs the resulting aerosol upward through a narrow-channel honeycomb core at the exit of which the flow is laminar and nearly uniform and shielded from surrounding air by a coaxial nitrogen shroud flow. The FPDSF is stabilized just above the honeycomb outlet where the rapid heating of the droplets causes the pyrolysis of the precursors and yields the desired products. The so synthesized nanoparticles can be directly deposited via thermophoresis on a downstream water-cooled plate or characterized via dilution sampling followed by Differential Mobility Analysis to measure their Size Distribution Function (SDF). The FPDSF is used first to manufacture nearly monodisperse (2-5nm) Nickel oxide (NiO) nanoparticles upon assessing the impact of the solution concentration and droplet size on their SDF. Then, NiO is nanostructured with carbon in a fuel-rich FPDSF and the thermo-catalytic activity of the products is assessed via gas speciation. Additional experiments are being performed to manufacture nanostructured catalysts of nickel-molybdenum-cobalt (NiMoCo) as well as lithium-nickel-manganese-cobalt (NMC) for applications in batteries.