| 摘要 |
A nitrogen oxide sensor having at least one pair of electrodes, i.e., a first electrode and a second electrode, set in such a state that the electrodes come into contact with an oxide ion conducting solid electrolyte, wherein at least the first electrode is made of an oxide of a Group 7a or 8 element, particularly selected from among Mn, Fe, Co and Ni, or a substance containing the oxide, or a composite oxide (including oxygen-deficient one) containing a Group 7a or 8 element, particularly represented by the formula: ABO3, AB2O4, A2BO4 or ACBO4, or a substance containing the composite oxide. The oxide or composite oxide used as the electrode material is active for oxygen and NOx but little exhibits catalytic activity for CO2. Accordingly, the above sensor can act effectively without being affected by change in CO2 concentration even at a temperature of 600 DEG C or above, and therefore can detect the concentration of NOx with a high accuracy, when set in the flow of high-temperature exhaust gas. <IMAGE> |
