ELECTROCHEMICAL ELEMENT AND EXHAUST GAS PURIFYING METHOD

PROBLEM TO BE SOLVED: To provide an electrochemical element and an exhaust gas purifying method capable of decomposing and removing nitrogen oxide in exhaust gas by contacting excessive oxygen with exhaust including a small amount of nitrogen oxides, and impressing direct current voltage between the electrodes. SOLUTION: The electrochemical element is an element for performing electrochemical reaction for the object to be treated, and consists of five-layer structure of a first collector electrode, a cathode, a solid electrolyte having oxygen ion conductivity, an anode, and a second collector electrode. The cathode and the anode are constituted by a mixed conductive material having both ion conductivity and electronic conductivity. The mixed conductive material is compounded with the ion conductive material or the electronic conductive material at a predetermined composition ratio. COPYRIGHT: (C)2004,JPO