Catalysis by Design

	Catalysis by Design

The development of new catalytic materials is still dominated by empirical methods which are time consuming and expensive. We have been exploring computationally complex but experimentally simple systems to establish a "catalyst by Design" protocol that combines the power of theory and experiment for atomistic design of catalytically active sites. This protocol can translate the fundamental insights gained directly to a complete catalyst system that can be technically deployed. The essential component of this approach is that the catalysts are iteratively examined by both theoretical and experimental methods. This approach involves state-of-the-art first principle density functional theory (DFT) calculations, experimental design of catalyst sites, and sub-Angstrom resolution imaging with an aberration-corrected electron microscope (ACEM) to characterize the microstructure.

Our theoretical studies show that platinum atom on θ-alumina 010 surface is diamagnetic and bonded to two surface oxygen atoms. We have experimentally synthesized platinum on θ-alumina samples and found platinum single atoms and 10-20 atom clusters on θ-alumina surface by ACEM. The CO oxidation on these nanoclusters initiates at lower temperatures than supported platinum particles. Theoretical studies are continuing to find a catalyst system that can be experimentally synthesized can withstand extended exposure to operating conditions without sintering. Such catalyst will dramatically reduce the cost of emission treatment catalyst systems.

The financial assistance for this research is provided by DOE-EERE-OVT and is gratefully acknowledged.

The principal technical contact for this project is Dr. Chaitanya K. Narula, tel. (865) 574-8445, e-mail narulack@ornl.gov.