Proper concentration of O_2 and C_3H_6 promoted the reduction of NO to N_2,and the formation of coke was distinctly suppressed by excess oxygen.

• 反应体系中适当的O2和C3H6浓度可促进NO还原为N2；但过高的浓度反而可降低NO的还原活性；O2同时可起到抑制积炭、清洁催化剂表面的作用.