A series of MnO₂ (with different crystal types) doping CeO₂ catalysts were synthesized by combining hydrothermal method and impregnation method, and the SCR activity and N₂O formation of the catalysts were investigated. The results showed that NO conversion rate of CeO₂ @ α-MnO₂, CeO₂ @ β-MnO₂ and CeO₂ @ γ-MnO₂ catalysts from 75 to 250 °C was always more than 95%, which showed excellent low-temperature NH₃-SCR activity. N₂O amount produced by CeO₂ @ α-MnO₂, CeO₂ @ β-MnO₂ and CeO₂ @ γ-MnO₂ catalysts during denitrification all reduced at 75–125 °C comparing with pure MnO₂, and the N₂O in denitration process mainly came from SCR reaction, but not from direct oxidation of NH₃. Besides, the reducibility and acidity of the complex oxides catalyst were improved, which was more beneficial to the reaction of adsorbed NH₃ with NO, thus reducing the direct oxidation of adsorbed NH₃ by O₂ and inhibiting the formation of N₂O. What’s more, the effect of Ce and different crystal types of MnO₂ also influenced N₂O generation behavior. Moreover, the SCR reaction of CeO₂ @ α-MnO₂ and CeO₂ @ β-MnO₂ catalysts mainly followed Eley-Rideal (E-R) mechanism, while CeO₂ @ γ-MnO₂ catalyst followed Langmuir-Hinshelwood (L-H) mechanism.

采用水热法和浸渍法相结合的方法合成了一系列MnO ₂（不同晶型）掺杂CeO _{2催化剂，并研究了催化剂的SCR活性和N 2} O的生成情况。结果表明，CeO ₂ @α-MnO ₂、CeO ₂ @ β-MnO ₂和CeO ₂ @ γ-MnO ₂催化剂在75~250 ℃的NO转化率始终在95%以上，表现出优异的低-温度 NH ₃ -SCR 活性。_{CeO 2} @ α-MnO ₂、CeO ₂ @ β-MnO产生的N _{2 O量2}和CeO ₂ @ γ-MnO _{2催化剂在脱硝过程中与纯MnO 2}相比均在75~125 ℃还原，脱硝过程中的N ₂ O主要来自SCR反应，而非NH ₃的直接氧化。此外，复合氧化物催化剂的还原性和酸性都有所提高，更有利于吸附的NH ₃与NO的反应，从而减少了O _{2对吸附的NH 3}的直接氧化，抑制了N ₂ O的生成。此外，Ce和不同晶型的MnO ₂也影响N ₂O代行为。此外，CeO ₂ @ α-MnO ₂和CeO ₂ @ β-MnO ₂催化剂的SCR反应主要遵循Eley-Rideal（ER）机制，而CeO ₂ @ γ-MnO ₂催化剂遵循Langmuir-Hinshelwood（LH）机制。