Low-PGM Catalysts for Automotive Catalytic Converters

Platinum group metals (PGMs) such as palladium and platinum are widely used in catalysts for existing catalytic converters to meet the ever-tightening of emission standards, but the high costs and market volatility risks associated with PGM call for the reduction of PGM content in the catalysts. This proposal addresses this need by developing a new strategy in the preparation of low-PGM nanoalloy catalysts for catalytic converters. Approaches and Innovations: The goal of Phase I work is to demonstrate the feasibility of preparation of low-Pt (or Pd) nanoalloy catalysts of optimal different combinations of metal oxides with balanced activity and stability as oxidation catalysts. The overall approaches are two-fold: (1) preparation of nanoalloy catalysts with low content of Pt or Pd by alloying with low-cost transition metals (Cu, Ni, Co, V), in which the Pt/Pd loading in the nanoalloy particles will be lower than that of traditional pure Pt/Pd particles by at least a factor of 50%, and (2) dispersing the metal oxide supported Pt or Pd-alloy nanoparticles in the washcoat on honeycomb monoliths. The proposed work builds upon patented technologies for nanoalloy synthesis by the Team Members of the project, and move beyond the current state-of-the-art of three-way catalyst washcoat preparation, which is new in catalytic converter technology in terms of lowering the PGM content to a great extent. A key technical challenge is the ability to achieve an optimal balance of the activity and stability under low-PGM level in the catalyst. The success in addressing this challenge by the proposed approaches is expected to lead a breakthrough in low-PGM catalyst for automotive emission control systems and applications. Objectives and Tasks of Phase I Work: During Phase I, the tasks include (1) preparing an optimal Pt(or Pd)-alloy composition in combination with the desired washcoat supports, (2) determining the morphology and structure of the washcoat, and (3) identifying the optimal catalytic performance of the catalysts in terms of catalytic activity and durability comparable to the current catalyst systems. Commercial Applications and Benefits: Manufacturing low-cost and efficient catalysts for three-way vehicle catalytic converters and industrial emission control systems will be the focus of the commercial applications. The proposed catalysts are anticipated to reduce the loading of platinum or palladium in the catalysts by more than 50%. The establishment of the low-PGM catalyst manufacturing technology and the catalyst product evaluation in catalytic converters for enabling competition in the catalyst market will be key areas of the project expansion if Phase II and Phase III continuing efforts are warranted. Key Words: Platinum group metal (PGM), Low-PGM catalysts, Nanoalloys, Three-way catalytic converters 1