A nitrogen oxide (NOx) abatement system is provided. The system includes a power generation device for generating power from a hydrogen-element containing fuel, an exhaust conduit in flow communication with an exhaust stream containing NOx which comes from the power generation device, a plasma reactor for reforming a portion of the hydrogen-element containing fuel with nitrogen to produce ammonia, and a NOx abatement reactor containing ammonia selective catalytic reduction (NH3-SCR) catalyst for receiving the exhaust stream and the ammonia and reducing NOx in the exhaust stream by causing the NOx to react with the ammonia to form nitrogen.