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

下一代节能内燃机需要改进排气系统中的催化转换器。提出的研究解决了这些催化剂的设计采用新的多孔结构。总体目标是减少废气排放，同时最大限度地减少对燃油经济性的影响，并减少对铂和钯等贵金属的需求。这项拟议中的研究是通用汽车全球研发中心和新墨西哥大学之间的产学研合作。该项目将为学生和早期职业研究人员提供机会，了解实施废气排放控制新技术所面临的挑战。这里所面临的研究挑战影响了用于满足能源、材料和燃料需求的整个多相催化剂类别。汽车尾气催化剂受到高温的影响，通过奥斯特瓦尔德成熟导致纳米颗粒尺寸的增长和活性的丧失。该研究将探讨孔隙结构和化学在奥斯特瓦尔德成熟过程中移动物种运输中的作用，以及在捕获移动物种以限制颗粒生长中的作用。模拟多孔催化剂将通过系统控制孔隙的大小和孔隙网络的连通性来合成。将研究流动物种的运输速率。改变表面化学性质可以影响扩散传输，也可以有效地捕获从纳米颗粒发射的移动物种。这些模型研究的总体结果是由于孔隙中运输速率的降低而导致颗粒生长速率的降低。这些多孔催化剂模型将转化为粉末催化剂，并使用行业合作伙伴的设备在现实条件下进行测试。工业界和大学研究人员的密切参与对于验证概念和模型至关重要。为了使这项研究取得成功，通用汽车在人员、时间和设施方面投入了大量资源。此次合作将有助于解决催化剂烧结方面的重大未知问题，并将在合成具有更好反应性和更有效利用贵金属的新型催化剂方面取得进展。该项目由学术与工业联络资助机会（GOALI）共同资助。

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).