ELECTROCHEMICAL ELEMENT AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To efficiently decompose even a very small amt. of nitrogen oxide at relatively low temp. in low current density under an atmosphere high in the concn. of oxygen by providing an oxygen ion conductive solid electrolyte substrate and a pair of the positive and negative electrode films formed to both opposed surfaces of the solid electrolyte substrate. SOLUTION: An electrochemical element is constituted by forming a negative electrode film 2 to one of the opposed surfaces of a flat-shaped acid ion conductive solid electrolyte substrate 1 and forming a positive electrode film to the other one of those surfaces thereof and lead wires 4, 5 are respectively connected to the negative and positive electrode films 2, 3. Since a pair of the positive and negative electrode films 2, 3 are formed to both opposed surfaces of the oxygen ion conductive solid electrolyte substrate 1, NOx molecules in the vicinity of the element are dissociated into nitrogen and oxygen on the negative electrode film 2 in the presence of oxygen to be adsorbed and dissociated oxygen is electrochemically reacted on the negative electrode film 2 to be taken in the oxygen ion conductive electrolyte substrate 1. Oxygen is discharged to the outside as oxygen molecules on the positive electrode film 3 and dissociated nitrogen is discharged to the outside as nitrogen molecules on the negative electrode film 2.