Low temperature electrochemical catalysts using a BITAVOX electrolyte

For the first time, electrochemical promotion (EP) was evidenced on a multi-layer electrochemical catalyst with a BIMEVOX ceramic used as an electrolyte. The electrochemical catalysts were tested for two environmental applications: selective catalytic reduction (SCR) of NOx by propene under lean-burn conditions and propene combustion. Thin Pt films were sputtered on BITAVOX.20 (Bi 2V 0.8Ta 0.2O 5.5− δ ) dense membranes. The thickness of the Pt films was less than 100 nm which led to a very small amount of Pt. First experiments revealed the formation of a Bi x Pt 1− x alloy, likely due to a slight reduction of the electrolyte. A new geometry was then proposed with the insertion of a YSZ barrier layer of a few nanometers between the catalyst and the electrolyte. Electrochemical promotion (EP) was evidenced for this system at low temperature (200–300 °C) under lean-burn conditions for both reactions. In the case of propene combustion, EP was maintained even in the presence of steam.