| 摘要 |
PROBLEM TO BE SOLVED: To keep high reliability over a long period and perform a quick measurement by forming a working electrode layer comprising a rare earth metal oxide and zeolite on the surface of a solid electrolyte layer. SOLUTION: This sensor element is formed of a working electrode layer 1 containing an electron conductive material and an auxiliary electrode material on the surface of a solid electrolyte layer 2 and a reference electrode layer 3 containing an electron conductive material. The arrangement of the working electrode layer 1 and the reference electrode layer 3 is not particularly limited as long as both the electrode layers 1, 3 are contact with the solid electrolyte layer 2. The working electrode layer 1 contains a rare earth metal oxide and zeolite. As the rare earth element of the rare earth metal oxide, La and Ld are preferred. In the zeolite, Na<+> contained in Na-USY is preferably substituted by Li<+> . The working electrode layer 1 preferably contains 1-60 wt.% of the rare earth metal oxide and 0.5-5 wt.% of the zeolite. The exchange ratio of the cation contained in the zeolite by other cations is preferably set to 70% or more. |
