Promoted Platinum Catalytic Activity and Thermal Stability with Nano-Scale Cobalt Oxide Coating via Atomic Layer Deposition
Many methods have been tried to form core shell structures to encapsulate the metal nanoparticles with porous materials to minimize sintering. The nanoparticles with a protective shell show good sintering resistance. However in some cases the catalysis performance decreases because the thick protective shell blocks the access of the reactants. New methods are needed to improve the controllability of the coating layer thickness and structure to stabilize the metal nanoparticles and at the same time maintain the catalysis performance. Atomic layer deposition (ALD) shows it unique advantages in sub-nanometer thin film thickness control due to the self-limiting growth nature. Recent works encapsulate the palladium nanoparticles with porous Al2O3 through ALD that effectively prevents sintering and coking in the ethane oxidation reactions.
Here we report the use of active oxide layer to coat the platinum NPs for CO oxidation. Our results indicate that with proper thickness control of the coating layer the catalysts have good thermal stability. At the same time the platinum and the active ingredients in the oxide layer may also form alloy particles, further promoting the total catalysis performance.
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