Modulating the low-temperature NH3-SCR activity of bimetallic MOF-derived MnCeOx/C catalyst via the molar ratio of manganese and cerium

A series of MnCeO x /C catalysts were synthesized by high-temperature pyrolysis under nitrogen atmosphere. The effects of different Mn/Ce molar ratios (2:1, 3:1, 4:1) on the structure, physicochemical properties and catalytic activity of the catalysts were investigated, and the H 2 O and SO 2 resistance was also explored. • Investigate the effect of different Mn/Ce molar ratios on catalyst performance. • The addition of Ce promotes the formation of a “fast SCR” reaction. • The Mn3Ce1O x /C catalyst displays excellent low-temperature activity. The elimination of nitrogen oxides has become a focal point in the field of the control of air pollution. A series of MnCeO x /C catalysts are synthesized using in-situ pyrolysis under N 2 atmosphere using bimetallic Mn/Ce-MOF as the precursor. The effects of different Mn/Ce molar ratios on the structure, physicochemical properties and NH 3 -SCR performance are investigated. The results show that the Mn3Ce1O x /C catalyst displays excellent low-temperature activity (NO x conversion is more than 90 %) at 175–275 ℃. This is attributed to the large specific surface area of the Mn3Ce1O x /C, while the addition of Ce promotes the formation of oxygen vacancies through the Mn 3+ +Ce 4+ ↔ Ce 3+ + Mn 4+ redox cycle, which further facilitates the oxidation of NO to NO 2 , resulting in the formation of a “fast SCR” reaction. Meanwhile, the Mn3Ce1O x /C catalyst has prominent tolerance to H 2 O and SO 2 , which is attributed to the sacrificial site Ce to protect the active component Mn as well as the hydrophobicity of the MOF-derived carbon material. This work provides a novel approach for designing high-performance low-temperature SCR catalysts.