MOO3 TIO2 AND BI2MOO6 AS AMMONIA SENSORS

Ammonia sensors based on catalytic oxides such as V2O5, MoO3 and alpha -, beta- and gamma-bismuth molybdates have been investigate. MoO3 (15 mol%) supported on TiO2 and gamma-Bi2MoO6 both exhibit satisfactory se nsing characteristics for NH3, with a reasonably low working temperatu re (500-575 K) and a minimum detection limit of 10 ppm. Humidity has n o measurable effect on the performance of these materials. ESR studies show the formation of Mo5+ species on these oxides on contact with NH 3.