ELECTROCHEMICAL PRODUCTION OF ACTIVE OXYGEN AND METHOD FOR ACCELERATING SELECTIVE REDUCTION REACTION OF NITROGEN OXIDE (NOx) USING ACTIVE OXYGEN

摘要

PROBLEM TO BE SOLVED: To provide electrochemical production of active oxygen and a method for accelerating selective reduction of nitrogen oxide (NOx) by the active oxygen. SOLUTION: A lean-burn combustion exhaust gas containing NOx, hydrocarbons, and oxygen is introduced in a gas chamber containing a yttria- stabilized zirconia (YSZ) as a solid electrolytic substance and a NOx selective reduction catalyst by hydrocarbons as a positive or negative work electrode and voltage is applied to the foregoing work electrode and the foregoing solid electrolytic substance to produce active oxygen on the surface of the foregoing work electrode and partially oxidize the hydrocarbons in the foregoing gas and also NO to NO2 gas to produce their intermediate substances and owing to the reactions of these intermediate substances, NOx selective reduction reaction is promoted to reduce NOx to nitrogen.