Multi Layered Zirconia Oxygen Sensor with Modified Rhodium Catalyst Electrode

This paper describes the design and operation of the multi-layered zirconia heated exhaust gas oxygen sensor having small-sized and sheet-shaped sensing element.

This sensor uses an electrode modified with a rhodium catalyst and heater by means of the thick-film technique. This modification of an electrode's composition and construction affects the reaction on unburned components in exhaust gas as well as the sensor performance.

By the addition of a rhodium catalyst, the zirconia exhaust gas oxygen sensor shows acute sensitivity and faster response properties in the transient state on emission component(NOx) generation, in such a way that these sensors show better emission control properties for reduction of NOx emission in current emission control systems.

The addition of a rhodium catalyst reduces the green effect of sensor properties, and no significant change of emission control properties is observed after 50,000 equivalent miles using the engine dynamometer durability test.