摘要
Cu/SSZ-13 catalysts with the nearly same contents of copper species were prepared by ion exchange technology with copper acetate, copper chloride, copper nitrate and copper sulfate as precursors. The effects of copper source on NH3 selective catalytic reduction (NH3-SCR) were probed detailedly. The physicochemical properties of the catalysts were investigated by XRD, ICP, N-2 absorption-desorption, SEM, H-2-TPR, XPS and NH3-TPD. The results of activity test display that the performance of Cu/SSZ-13 zeolite for ammonia selective catalytic reduction at low temperature is significantly different. The light off temperature T50 (the temperature when conversion efficiency >= 50%) follows the order of Cu (copper acetate)/SSZ-13<Cu (copper chloride)/SSZ-13<Cu (copper sulfate)/SSZ-13<Cu Cu (copper nitrate)/SSZ-13. The characterization results manifest that the distribution and quantity of copper species and the acidity of zeolite catalysts are affected by copper source. The Cu/SSZ-13 catalyst prepared with copper acetate as precursor possesses the largest number of isolated Cu2+ and strong L acid sites, which are conducive to the low-temperature NH3-SCR reaction.