Catalytic Properties of Pd Modified Cu/SAPO-34 for NOx Removal from Diesel Engine

The Cu/SAPO-34 catalysts with different Cu contents were prepared by in situ hydrothermal synthesis. The selected Cu/SAPO-34 was modified by impregnating 1 wt% Pd(NO3)(3). The morphology and structure of the samples were characterized via XRD and SEM techniques. The effects of Cu contents and the Pd modification on the de-NOx activity of the samples were investigated through the selective catalytic reduction by C3H6 and NH3. The Cu contents do not change the skeleton structure of the SAPO-34 crystalline and the Cu/SAPO-34 catalysts with Cu/Si ratios of 0.05, 0.1, and 0.2 have better de-NOx activity than other catalysts. The addition of Pd can improve the de-NOx activity of the Cu/SAPO-34 catalysts. The maximum of NO conversion of samples with Pd could reach 90%. Besides, the effect of aging treatment for Cu/SAPO-34 catalysts with and without Pd on the de-NOx activity was also investigated. The results indicated that the Cu/SAPO-34 catalysts modified by Pd have better antiaging performance than raw samples.