Principal Investigator: Susannah L. Scott
Institution: University of California - Santa Barbara
Analysis (rationale for decision):
The project is designed to explore a new paradigm for manufacturing precious metal nanoparticles. Stored in disassembled form as dispersed metal ions in a complex oxide reservoir, the nanoparticles are generated spontaneously and reversibly at the surface of the reservoir in response to a specific environmental stimulus. When not in use, they revert to the stored form, which results in dramatically prolonged lifetimes and stabilization against particle growth. The theoretical basis for this phenomenon will be developed, paying particular attention to the ability of mixed oxide structures to stabilize precious metal ions and to promote their mobility. New density functional methods for treating perovskite structures and metal-oxide interfaces will be implemented for both real and hypothetical structures, and the resulting predictions will be tested experimentally by synthesizing and characterizing materials. An immediate application for these materials exists in catalysis, where nanoparticles of precious metals possess unusual reactivity and selectivity compared to their bulk metal counterparts. Although such nanoparticles can be readily prepared by conventional methods, they rapidly lose their catalytic activity under reaction conditions. The ability to generate and regenerate nanoparticles from a reservoir avoids the need for complex syntheses, maximizes catalyst productivity, prolongs activity, facilitates metal recovery, and ultimately prevents environmental contamination by the nanomaterials. If the phenomenon can be shown to be general, it could revolutionize the field of catalysis, decreasing by orders of magnitude the amounts of precious metal required to achieve desired transformations. Given their expense and rarity, this intelligent use of a natural resource could enable widespread adoption of nanocatalysts in applications such as fuel cells. A collaborative program of research and education will be performed at two institutions. An innovative Pennsylvania Science Teachers Institute will be involved, and a summer workshop will be part of the California Nanosystems Institute's K-12 program.
