Lean NOx Reduction in Two Stages: Non-thermal Plasma Followed by Heterogeneous Catalysis

We present data in this paper showing that non-thermal plasma in combination with heterogeneous catalysis is a promising technique for the treatment of NOx in diesel exhaust. Using a commonly available zeolite catalyst, sodium Y, to treat synthetic diesel exhaust we report approximately 50% chemical reduction of NOx over a broad, representative temperature range. We have measured the overall efficiency as a function of the temperature and hydrocarbon concentration. The direct detection of N₂ and N₂O when the background gas is replaced by helium confirms that true chemical reduction is occurring.