A combined Ag/Al₂O₃ and Pd/Al₂O₃ catalyst was investigated for the selective catalytic reduction (SCR) of NO_x by H₂-assisted C₃H₆ in the presence of excessive O₂. The coexistent H₂ significantly lowered the active temperature window of the de-NO_x reaction because of the enhanced partial oxidation of C₃H₆ and NO oxidation to NO₂. A low Ag loading of 1 wt% exhibited better de-NO_x performance than that attained using 2 wt% Ag. Although Ag/Al₂O₃ exhibited a high resistance to hydrothermal aging, a high reaction temperature (>500 °C) was required to oxidize CO and C₃H₆ completely. In contrast to Ag/Al₂O₃, Pd/Al₂O₃ suppressed C₃H₆ and CO slip at relatively low temperatures, and a complete oxidation of C₃H₆ and CO was achieved at 195–275 °C and 240–275 °C, respectively, under varying SCR conditions and Pd contents (0.5–1.5 wt%); however, 30% de-NO_x performance in a narrow temperature window of 210–240 °C was attained. The best configuration was found to be a sequential arrangement of 1Ag/Al₂O₃ followed by 1Pd/Al₂O₃, which enabled the reduction of NO_x, C₃H₆, CO, and H₂ over wide reaction temperatures, unlike the stand-alone configuration. In this configuration, the reacted NO_x was reduced to N₂ with negligible formation of by-products, even after hydrothermal aging.

研究了组合的 Ag/Al ₂ O ₃和 Pd/Al ₂ O ₃催化剂在过量 O ₂存在下通过 H ₂辅助的 C ₃ H ₆选择性催化还原 (SCR) NO _x。由于C ₃ H _{6 的}部分氧化和NO 氧化为NO ₂的增强，共存的H ₂显着降低了脱NO _x反应的活性温度窗口。的1的低Ag负载量％（重量）具有更好的脱NO _X比使用2重量％的Ag达到的性能。虽然 Ag/Al ₂O ₃表现出对水热老化的高抵抗力，需要高反应温度（> 500°C）来完全氧化CO和C ₃ H ₆。与 Ag/Al ₂ O _{3 相比}，Pd/Al ₂ O ₃在相对较低的温度下抑制了 C ₃ H ₆和 CO 逃逸，并且在 195–275 °C 和 240 ℃下实现了 C ₃ H ₆和 CO的完全氧化–275 °C，分别在不同的 SCR 条件和 Pd 含量 (0.5–1.5 wt%) 下；然而，30% 脱氮_x在 210-240°C 的窄温度窗口中实现了性能。发现最好的配置是 1Ag/Al ₂ O ₃的顺序排列，然后是 1Pd/Al ₂ O ₃，它能够在较宽的反应温度下减少 NO _x、C ₃ H ₆、CO 和 H ₂，这与单机配置。在该配置中，即使在水热老化之后，反应的NO _x也被还原为N ₂且副产物的形成可忽略不计。