Sensitivity enhancement for CO gas detection using a SnO2-CeO2-PdOx system

Thick film CO sensors were fabricated using SnO2 loaded with CeO2 and PdOx. The composition that gave highest sensitivity for CO was in the wt.% ratio of SnO2:CeO2:PdOx as 94:5:1. The nano-crystalline powders of SnO2-CeO2-PdOx composites synthesized by sol-gel method were screen-printed on alumina substrates. The fabricated sensors were also tested against other gases like H2, CH4, C3H8, C2H5OH, NOx and SO2. The composite material was found sensitive against CO in the working temperature range between 120 and 180 °C, with minor interference of other gases. The CO gas as low as 40 ppm can be detected by the present fabricated sensors.