I-Corps: Support Promoted Low-temperature Emission Control Catalysts

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The broader impact/commercial potential of this I-Corps project is to reduce emission of pollutant exhaust gases from vehicles by enhancing the conversion rate of pollutant emission gases to nonpolluting gases at lower temperature. Current automobile catalytic converters used for this purpose are comprised of emission control catalysts which are relatively ineffective during the cold start period because the cold start temperature is lower than the light-off temperature of catalysts, leading to pollutants emitted into the ambient air. The adoption of the novel shape-controlled cerium oxide supported emission control catalysts from this project will enable 90% conversion rate below 423 K, and thus have a profound impact on environmental and public health protection. In addition, the support promoted catalyst technology from this project will provide a generalizable strategy for the design of efficient and sustainable emission control catalysts with low-loading of costly precious metal catalysts, thereby leading to reduced prices and giving catalytic converter manufacturers a competitive advantage. These low temperature emission control catalysts may also be applied in many off-gas cleaning applications including in electrical power plants, refineries and chemical plants, and surface coating facilities.This I-Corps project further develops a technology that combines shape-controlled synthesis of cerium oxide catalyst support nanomaterials with surface engineering activation via chemical etching and plasma treatment. This technology represents a significant advancement to the field of emission control catalysts by: (1) tuning the shapes of cerium oxide support for obtaining more reactive surfaces and mobile oxygen species accessible on the crystal surface for gas conversion reactions; (2) increasing the surface defect concentration of cerium oxide support via chemical etching to better trap metal catalyst nanoclusters or even single atoms, thus leading to enhanced long-term thermal stability/durability and decreased loading amount of precious metals; and (3) activating metal-support interface using plasma treatment. Together these strategies enable fine tuning of the atomic-level structure and chemistry at the catalyst-support interface, which can offer low energy barriers for the formation of key intermediates and open reaction paths and active sites for pollutant gases conversion at lower temperature.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.