MoO₃/TiO₂ and Bi₂MoO₆ as ammonia sensors

Abstract

Ammonia sensors based on catalytic oxides such as V_2O5, MoO₃ and α, β- and γ-bismuth molybdates have been investigated. MoO₃ (15 mo1%) supported on TiO₂ and γ-Bi₂MoO₆ both exhibit satisfactory sensing characteristics for NH₃, with a reasonably low working temperature (500-575 K) and a minimum detection limit of 10 ppm. Humidity has no measurable effect on the performance of these materials. ESR studies how the formation of Mo⁵⁺ species these oxides on contact with NH₃.