A Highly Effective MnNdOx Catalyst for the Selective Catalytic Reduction of NOxwith NH3

Nd was used as the modifier to improve the NH3-selective catalytic reduction (SCR) performance of MnOxcatalyst used in NOxabatement. The results of the activity test indicated that MnNdOx-0.1 catalyst displayed remarkable catalytic activity and N2selectivity in the temperature range of 50–300 °C. Characterization results proved the enhanced reducibility and the facilitated NH3and NOxadsorption over MnNdOx-0.1 catalyst, accompanied by the existence of more Mn4+and surface adsorbed oxygen species over its surface. The results of the in situ diffuse reflectance infrared Fourier transform study pointed out that the NH3-SCR reaction over the MnNdOx-0.1 catalyst was mainly under the control of the Langmuir–Hinshelwood mechanism (≤100 °C); when the reaction temperature was over 200 °C, the Eley–Rideal mechanism was dominant. More adsorbed NOxand NH3species over the MnNdOx-0.1 catalyst, along with the activation effect of Nd on the adsorbed reactants, had a facilitation impact on the SCR reaction process over the MnNdOx-0.1 catalyst.