A series of Sm–Mn mixed oxide catalysts were prepared via precipitation using various precipitants, namely Na₂CO₃ (NH₄)₂CO₃, and NH₃·H₂O, and evaluated for the selective catalytic reduction (SCR) of NO_x with NH₃ at low temperatures. Various characterisation techniques were used to determine the physicochemical properties of the catalysts, and it is found that their catalytic performance is greatly influenced by the nature of the precipitation agent used. It is found that Sm_0.1Mn–Na₂CO₃ and Sm_0.1Mn-(NH₄)₂CO₃ exhibit superior catalytic performance in the SCR reaction to that of Sm_0.1Mn–NH₃·H₂O due to an abundance of surface acid sites, high surface concentration of Mn⁴⁺, and high NO oxidation capacity. From in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) analysis, we conclude that the Sm–Mn catalysts follow both Eley-Rideal and Langmuir–Hinshelwood mechanisms, and that the Eley-Rideal mechanism is dominant at elevated temperatures.

_{使用不同的沉淀剂，即 Na 2} CO ₃ (NH ₄ ) ₂ CO ₃和 NH ₃ ·H ₂ O，通过沉淀法制备了一系列 Sm-Mn 混合氧化物催化剂，并评估了 NO 的选择性催化还原 (SCR) _x与 NH ₃在低温下。各种表征技术被用来确定催化剂的物理化学性质，发现它们的催化性能很大程度上受所用沉淀剂的性质的影响。发现 Sm _0.1 Mn-Na ₂ CO ₃和 Sm _0.1 Mn-(NH₄ ) ₂ CO ₃在SCR反应中表现出优于Sm _0.1 Mn–NH ₃ ·H ₂ O的催化性能，这是由于表面酸位点丰富、Mn ⁴⁺表面浓度高、NO氧化能力强。通过原位漫反射红外傅里叶变换光谱 (DRIFT) 分析，我们得出结论，Sm-Mn 催化剂遵循 Eley- Rideal和 Langmuir-Hinshelwood 机制，并且 Eley-Rideal 机制在高温下占主导地位。