Activity Test and Mechanism Study of 3DOM Ce_0.8M_0.1Zr_0.1O₂ (M=Cr, Sn, Fe, Co, Ni, Mn, Cu) Catalyst in the Selective Catalytic Reduction of NO by CO**

Abstract

The results show that the NO conversion rate of 3DOM Ce 0.8 Cu 0.1 Zr 0.1 O 2 catalyst at a lower temperature (150 °C) is close to 60 %. Besides, 3DOM Ce 0.8 Cu 0.1 Zr 0.1 O 2 kept a stable NO removal efficiency within a wide range of gas hourly space velocity (GHSV) and long reaction time and exhibited remarkable resistance to H 2 O and SO 2 poisoning, both individually and simultaneously. At the same time, the formation of the 3DOM structure not only improves the reduction performance and surface active sites of the catalyst, but also forms more oxygen defects and Ce 3 + in the catalyst due to the strong synergistic effect of metal ions and ceria, which improves the surface oxygen concentration of the composite oxide catalyst and further improves the catalytic activity. In addition, the doping of copper ions on the surface of the 3DOM Cu-CZ catalyst can improve the activity of the catalyst and it can get trapped by CO to form Cu + -CO, which plays an important role in the NO + CO reaction at low temperature. The existence of oxygen vacancy at high temperature is beneficial to the activation of O 2 and the dissociation of NO in the process of CO oxidation. The reaction of NO + CO over 3DOM Cu-CZ catalyst follows LÀ H and EÀ R mechanism respectively.

Stability challenges and prospects for the industrial application of non‐noble catalysts for selective catalytic reduction of NOx by CO (CO‐SCR)

“…Metal doping is one of the most common and extensively studied methods for enhancing the SO 2 resistance of catalysts, and various elements such as Cr, Sn, Fe, Mn, and Cu have been studied for their impact on the SO 2 resistance of catalysts (Figure 7a). Among these, Cu doping displayed the most significant improvement in sulfur resistance of CeZrO x catalyst [29c] . Furthermore, co‐doping of Cr and Cu in Ce‐based catalyst can further enhance its SO 2 tolerance, likely due to an increase in surface medium and strong acid sites [46] .…”

“… (a) SO 2 resistance of CeZrO x doped with Cr (a), Sn (b), Fe (c), Co (d), Ni (e), Mn (f), Cu (g), and pure CeZrO x (h) [29c] Reproduced from Ref. [29c] Copyright 2021, Wiley‐VCH.…”

Poisoning Mechanism Study of Metal Ions on a Three-Dimensional Ordered Macroporous Structure Ce0.2Mn0.2/3DOM-TiO2 Catalyst for Low-Temperature SCR of NO with NH3

“…In recent years, a three-dimensional ordered macroporous structure (3DOM) has received increasing attention in the catalysis field due to the specially ordered macroporous structure and outstanding physicochemical properties. , The three-dimensional ordered macroporous structure has a unique ordered macroporous structure, more surface-adsorbed oxygen species, and sufficient surface acid sites. , Liu et al prepared a 3DOM Ce 0.8 Cu 0.1 Zr 0.1 catalyst which exhibited excellent de-NO x activity due to the strong redox and more surface active sites. The 3DOM-Mn 3 Ce 1 catalyst showed high SCR activity at low temperatures, which was owing to the excellent redox ability and rich Lewis and Bronsted acid sites of the catalysts …”