A HYDROGEN SENSOR-BASED ON THE OPTICAL-GENERATION OF SURFACE-PLASMONSIN A PALLADIUM ALLOY

The optical generation of surface plasmons in palladium/nickel alloys is used to construct a reliable hydrogen sensor. Absorption of hydroge n by the palladium alloy results in large changes in reflected light i ntensity (6.6% per 1% change in H-2 concentration) from a reflection o ff an alloy/glass interface. The palladium alloy is found to be far mo re suited than pure palladium for use in the sensor, owing to its grea ter mechanical strength and resistance to poisoning by other chemical species. The sensor performance is not effected by the presence of com mon atmospheric constituents, such as CO and CH4, or by lack of oxygen in the atmosphere (unlike many catalytic sensors).