The effect of accelerated hydrothermal aging on NH 3-SCR over Cu-Hbea catalyst

Diesel engines have good fuel efficiency. However, the excess of oxygen that is fed into the engine is also present in the exhaust stream. This disables the selectivity of the standard three-way catalyst towards NO x. The influence of hydrothermal aging on the SCR mechanism was studied. A trend towards less strong bound ammonia for higher aging temperatures is observed, which agreed with TPD experiments. Ammonia SCR is an important technique for reducing NO x from diesel and lean burn gasoline engines. Zeolite based catalysts are a good choice for this reaction. However, they can be hydrothermally aged. This is an abstract of a paper presented at the 2011 AIChE Annual Meeting (Minneapolis, MN 10/16-21/2011)