Preparation of Cu/Dy/S₂O₈^2-/Al-PILR catalyst and its catalytic performance for selective reduction of NO

By using rectorite as raw materials, the Al-pillared rectorite(Al-PILR) was synthetized, then the Cu/Dy/S₂O₈^2-/Al-PILR catalyst was prepared by loading of (NH₄)₂S₂O₈, Dy(NO₃)₃ and Cu(NO₃)₂ onto the Al-pillared rectorite step by step. The catalytic performance of the Cu/Dy/S₂O₈^2-/Al-PILR catalyst on the selective catalytic reduction of NO with propylene was investigated. The relationship between the structure and the performance of the Cu/Dy/S₂O₈^2-/Al-PILR catalyst was also explored by means of Low-angle X-ray diffraction (LAXRD), Surface area measurements (BET), Pyridine absorption infared spectrum (Py-IR), Infrared spectroscopy (IR), Thermal gravimetric analysis (TG) and Scanning electron microscope (SEM). The experimental results indicated that the Al pillaring agent could effectively insert into the layer of rectorite and remarkably enlarge the specific surface area, and S₂O₈^2- could obviously increase the Brönsted acid amount of the Al-pillared rectorite, Dy could further increase the Brönsted acid amount to improve the catalytic activity and thermal stability effectively. Therefore, the Cu/Dy/S₂O₈^2-/Al-PILR catalyst exhibited excellent catalytic performance. The NO conversion was up to 80.3% at 300℃ and 77. 6% even at the presence of 10% volume fraction of water vapor.