Cerium and zirconium oxide nanoparticles act as catalysts in reduction-oxidation ("redox") chemical processes, including methanol reformation, the water-gas shift reaction, and three-way catalysis (TWC). These catalysts comprise of metal oxides and combinations of precious metals, but suffer from low catalyst efficiency. Creating catalyst with high dopant densities can increase efficiency, but current methods are expensive and technically difficult. This technology presents a low-temperature, cost effective synthesis of palladium-doped cerium oxide or zirconium nanoparticles with a controllable, high dopant density.
This technology describes the synthesis of palladium doped cerium and zirconium oxide nanoparticles at low temperatures (up to 85C degrees), reducing energy costs and resulting in highly doped palladium nanoparticles. The amount of palladium dopant can be controlled from the amount of palladium precursor added to the reaction, allowing for tuning of dopant density. Furthermore, because the reaction is aqueous, the costs involved with purchasing and disposing of organic solvents are minimized. Unlike other methods, performing the reaction in solution does not compromise dopant density. This technology can produce palladium doped cerium oxide, palladium doped zirconium oxide and palladium doped cerium-zirconium oxide alloys, all of which can act as catalysts in fuel cell technology (as a methanol reformer), industrial plants (for water-gas shift reactions), and catalytic converters (for TWC).
The synthesized nanoparticles were characterized by high-resolution transmission electron microscopy and x-ray diffraction to show both their high uniformity as well as their palladium concentration.
Patent Pending (US 20120028795)
Patent Issued (US 7,449,163)
Tech Ventures Reference: IR M09-041