Hydrogen Engine Exhaust Aftertreatment

Hydrogen engines with lean combustion are a highly suitable solution for sustainable mobility, specifically for high-duty applications. To reach sufficient power densities, the engine needs to be combined with an aftertreatment system to convert NOx emissions.
In the presented project we experimentally investigated aftertreatment components and aftertreatment systems for their ability to convert the exhaust gas of a hydrogen engine. The catalysts and systems based on existing solutions from diesel engines. A hydrogen multi-cylinder engine was used for the measurements.
We observed, that hydrogen can be easily converted by an oxidation catalyst. The amount of precious metal loading required is believed to be lower than that required in diesel engines. No effluent N2O was detectible under warm conditions.
The problem of NOx reduction observed in hydrogen engines is comparable to that observed in diesel engines. However, hydrogen had a significant inhibitory effect on the SCR reaction of the used catalyst. For this reason, the use of an upstream oxidation catalyst appears to be necessary.
The levels of emitted hydrocarbons, carbon monoxide and