Selective detection of unburned-hydrocarbon in the exhaust gas using catalytic filter

Pd/LaMnO
₃
was used as a catalytic filter for Pt/SnO
₂
sensor to selectively detect propane, as a representative of unburned-hydrocarbons, in the presence of CO and NO for exhaust gas application. SnO
₂
was synthesized by a sol-gel method and LaMnO
₃
was prepared through a combustion synthesis recipie. The samples were impregnated with aqueous solutions of H
₂
PtCl
₆
and Pd(NO
₃
)
₂
.2H
₂
O to prepare 1.0 wt% Pt/SnO
₂
and 1.0 wt% Pd/LaMnO
₃
. By using Pd/LaMnO
₃
filter, the fabricated sensor responded to propane similar to a mixture of CO, NO and C
₃
H
₈
. Thus, the combination of Pd/LaMnO
₃
filter and Pt/SnO
₂
sensor becomes highly selective to propane in presence of CO and NO in the exhaust stream of a gasoline engine.