Selective Sensor to LPG in presence of CO using nanogold filter, operating at low temperature, with Pt/SnO2

In this paper, gold nanoparticles supported on iron oxide were used as an active filter to eliminate CO interfering effect on detection of propane as a combustible gas using lwt% Pt/SnO₂ sensor. A sol-gel method was used for the preparation of SnO₂, which was impregnated with hexachloroplatinic acid to obtain lwt% Pt/SnO₂. Gold/iron oxide was prepared by copercipitation method using an aqueous solution of HAuCl₄ and Fe(NO₃)3.9H₂O. Complete oxidation of CO by the active filter occurs at about 40degC but no oxidation of propane happens up to 190degC. Without using the filter, the Pt/SnO₂ sensor shows comparable sensitivity to both propane and CO. When the filter is placed in front of the sensor, its sensitivity to a mixture of CO and propane is exactly the same value as in presence of propane alone.