Core-Shell Cu–Y@SBA-15/Ce Catalyst for Wide Temperature Selective Catalytic Reduction of NOx by NH3

The Cu–Y@SBA-15/Ce catalysts with a core-shell structure is prepared using Cu–Y zeolite as the core and SBA-15/Ce as the shell. Cu–Y and CuCe–Y catalysts are also prepared. Their activities are investigated for the selective catalytic reduction of NOx using ammonia as reductant (NH3-SCR). As a comparison, the effect of different Cu and Ce loadings on the denitrification performance of CuCe–Y zeolite catalyst is also studied. Furthermore, the effect of SBA-15 shell on resistance to water is also investigated. The results show that the optimal loading of Cu and Ce is 2 and 4%, respectively. It is because that the introduction of moderate amounts of Ce and Cu facilitates the dispersion of the active components. The 2%Cu–Y@SBA-15/4%Ce catalyst has high activity (99% NOx conversion in the range of 250–450°C) and resistance to water and sulfur, which is due to the good hydrophobicity of the SBA-15 shell. In addition, the Ce active site can be sacrificed in the presence of SO2 to protect the Cu active site.