Plasma sprayed CuO coatings for gas sensing and catalytic conversion applications

Abstract Plasma spray was used to deposit copper oxide (CuO) coating for gas sensing and catalytic conversion applications. Amongst tin oxide (SnO2), tungsten oxide (WO3) and copper oxide (CuO), CuO showed efficient catalytic conversion. Therefore, CuO was selected to deposit catalyst coating. The gas sensing layer was produced on the alumina plate whereas the catalyst layer was produced on the silica-35 wt. % alumina perforated ceramic disc. Plasma sprayed CuO gas sensor coating showed maximum response % (110) towards 500 ppm carbon monoxide (CO) at 150 °C. This coating was useful to detect CO in a wide concentration range (500−5 ppm). It also demonstrated selective sensing capability towards CO in the presences of NO2 and i- C4H10. Next, CuO coatings were packed inside a fabricated test ring and tested for a catalytic conversion of gasoline engine emissions. CuO catalytic coatings could decrease CO, HC and NOx emissions by almost 80 %. This coating can thus, be used as a sense and shoot device to first detect harmful gases followed by its conversion to benign gases in hazardous environments such as automobile exhaust.