Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NO x by NH3 over MnCeO x Catalysts: The Promotion Effect and Mechanism

Changze Yang; Haixia Li; Anchao Zhang; Zhijun Sun; Xinmin Zhang; Shuaibo Zhang; Leying Jin; Zhiheng Song

doi:10.1021/acsomega.1c07000

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NO _x by NH₃ over MnCeO _x Catalysts: The Promotion Effect and Mechanism

ACS Omega. 2022 Feb 8;7(7):6381-6392. doi: 10.1021/acsomega.1c07000. eCollection 2022 Feb 22.

Authors

Changze Yang¹, Haixia Li¹, Anchao Zhang¹, Zhijun Sun¹, Xinmin Zhang¹, Shuaibo Zhang¹, Leying Jin¹, Zhiheng Song¹

Affiliation

¹ School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo 454000, China.

Abstract

A MnCeInO _x catalyst was prepared by a coprecipitation method for denitrification of NH₃-SCR (selective catalytic reduction). The catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller analysis, H₂ temperature-programmed reduction, and NH₃ temperature-programmed desorption. The NH₃-SCR activity and H₂O and SO₂ resistance of the catalysts were evaluated. The test results showed that the SCR and water resistance and sulfur resistance were good in the range of 125-225 °C. The calcination temperature of the Mn₆Ce_0.3In_0.7O _x catalyst preparation was studied. The crystallization of the Mn₆Ce_0.3In_0.7O _x catalyst was poor when calcined at 300 °C; however, the crystallization is excessive at a 500 °C calcination temperature. The influence of space velocity on the performance of the catalyst is great at 100-225 °C. FTIR test results showed that indium distribution on the surface of the catalyst reduced the content of sulfate on the surface, protected the acidic site of MnCe, and improved the sulfur resistance of the catalyst. The excellent performance of the Mn₆Ce_0.3In_0.7O _x catalyst may be due to its high content of Mn⁴⁺, surface adsorbed oxygen species, high specific surface area, redox sites and acid sites on the surface, high turnover frequency, and low apparent activation energy.