Clean-Air Technology

Oxidation catalysts for the exhaust gas purification of non-road machines

After-treatment of exhaust gases has led to major improvements in air quality in Germany, but require rare and expensive precious metals. In this project, high-performance exhaust catalytic converters are being developed for working machines with diesel engines.The aim is to develop exhaust gas catalytic converters that use as little precious metals as possible and are also resistant to ageing to ensure a long service life.

 

Summary

Working machines are usually operated with diesel engines. In recent years, legislators have also tightened the emission regulations for engines of work machines that are predominantly not used on roads and therefore do not require a license plate. This means that catalytic converters are required to meet the emission limits for carbon monoxide, hydrocarbons, nitrogen oxides and soot particles. Since the engines of work machines are often considerably larger than those of passenger cars, the catalytic converters must also have a corresponding volume. The active component used in oxidation catalytic converters is mainly the expensive and rare precious metal platinum. The tightening of the emission limits for work machines would significantly increase the demand for platinum.
In the project, oxidation catalysts with minimised precious metal content are developed for exhaust gas purification and tested under real conditions with regard to activity and ageing stability. In addition to the catalyst formulation, the coating plays an important role here. By doping with palladium, good ageing stability could be achieved despite an overall reduced precious metal content. By means of novel precious metal precursors and special manufacturing procedures, the formation of NO2, which usually occurs when using palladium, was minimised. This enables higher palladium contents with a lower total precious metal load and constant thermal ageing stability.
Overall, it has been possible to develop a catalyst formulation with a significantly lower precious metal content, based on processes and raw materials suitable for series production. Using various characterisation technologies, correlations between catalyst structure and activity could be established. For further evaluation, testing under real conditions for at least 4,000 operating hours is planned.

More Project Information

Project title: EDMIN - Entwicklung von Oxidationskatalysatoren mit minimiertem Edelmetall-Gehalt für die Abgasreinigung von Non-Road-Maschinen

Reference number: 03X3580

Project period: 2013 - 2016

Project region: Germany

Project contact: This email address is being protected from spambots. You need JavaScript enabled to view it.

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* only available in german *

 

Source: German National Library of Science and Technology Hannover (TIB)