Detection of the ammonia loading of a Cu Chabazite SCR catalyst by a radio frequency-based method.

Zeolites are in use as catalyst materials in the selective catalytic reduction of NO x with NH 3 as reducing agent. An initial NH 3 -adsorption on the catalyst is essential for the reaction with NO and NO 2 to occur. Due to the adsorbed NH 3 , the proton conductivity of the zeolite increases markedly. This change of the electrical properties of the catalyst material can be monitored in a contactless way and in operando using a radio frequency-based method to determine the ammonia loading on the catalyst. In this work, the ammonia storage is examined on a copper exchanged Chabazite Cu-SSZ-13, a typical SCR catalyst as it is in use for serial applications, at different temperatures and various feed ratios. [ABSTRACT FROM AUTHOR]