Catalytic combustion of toluene on Pd-based monolithic catalyst without coating

A new Pd-based monolithic catalyst on cordierite honeycomb ceramics substrate without coating (Pd/cord) was prepared via electroless plating. The results of activity tests for catalytic combustion of toluene showed that Pd/cord catalysts with low Pd loading had good catalytic activities: toluene could light off at 201℃, then leap to 226℃ to burn out on Pd/cord catalyst with 0.24% Pd loading. And Pd/cord catalyst was also suitable for toluene catalytic combustion when space velocities and feed toluene concentrations varied in 6000h^-1~40000h^-1 and 0.5g/m³ ～8.0g/m³ respectively. During the 105h stability test of Pd/cord catalyst, the toluene conversion was kept above 97%, which indicated that this catalyst possessed good catalytic stability. The scanning electron microscope (SEM), X-ray diffraction (XRD) and temperature programmed reduction in hydrogen (H₂-TPR) characterizations showed that the sizes of PdO crystal particles in Pd/cord catalyst when Pd loading was 0.24%， PdO particles were also equably distributed on the surface of cordierite substrate with no overlapping aggregation phenomenon.