GOALI: Emission, transport and trapping of platinum group derived mobile species in automotive exhaust catalysts

University Of New Mexico, Albuquerque NM

Investigators

Abstract

Next-generation fuel-efficient combustion engines require improved catalytic converters in the exhaust system. The proposed research addresses the design of these catalysts by employing novel porous structures. The overarching goal is to reduce exhaust emissions while minimizing impact on fuel economy and reducing the need for precious metals such as Pt and Pd. The proposed research is an industry-university collaboration between GM Global R&D and the University of New Mexico. The project will provide opportunities for students and early career researchers to learn about the challenges in implementing new technologies for exhaust emissions control. The research challenge being addressed here impacts the entire class of heterogeneous catalysts used for meeting the needs for energy, materials and fuels. Automotive exhaust catalysts are subjected to elevated temperatures that lead to growth of nanoparticle size through Ostwald ripening and to loss of activity. The research will look into the role of pore structure and chemistry in the transport of mobile species during Ostwald ripening and in the trapping of the mobile species to limit the growth of particles. Model porous catalysts will be synthesized with systematic control of the size of the pores and the connectivity of the pore network. The transport rates of the mobile species will be studied. Modifying the surface chemistry can influence the diffusive transport and can also effectively trap the mobile species once they get emitted from nanoparticles. The overall outcome from these model studies is a decrease in particle growth rates due to decreased transport rates in pores. Insights from these model porous catalysts will be translated to powder catalysts and tested under realistic conditions using the facilities of the industry partner. The close participation of industry and university researchers is critical for validating the concepts and models. GM has committed significant resources in terms of people time and access to facilities, to enable this research to be successful. The partnership will help address significant unknowns in the understanding of catalyst sintering, and will lead to advances in the synthesis of novel catalysts with improved reactivity and more efficient use of precious metals. The project is co-funded by the Grant Opportunities for Academic Liaison with Industry (GOALI).