Exhaust gas oxygen sensor

Abstract

The present invention identifies a formulation for a subgroup of perovskite structure oxides that overcomes the outstanding problems for oxygen sensing in a combustion environment. The sub group has a formula ABOx where A is a large 3-valent ion, such as Pr3+, B is a transition metal ion, which is substituted to a small degree by tungsten (which has a stable valence of 6), and x indicates that the oxide can sustain a variable oxygen stoichiometry. A preferred general formulation is a single-phase perovskite structure AB1-yWyOx where y preferably lies between 0.03 and 0.15, more preferably between 0.05 and 0.10 and where x is close to 3. Preferred examples of compositions that can achieve these advantages include, but are not limited to, PrFe0.95W0.05Ox and LaFe0.95W0.05Ox.

Dependencies are inferred from the claim text.