Trace Co doping improves NH3-SCR performance and poisoning resistance of Ce-Mn-based catalysts

• One-step redox precipitation method for the preparation of trace Co-doped Ce-Mn-based catalysts with multiple applications. • A dual redox cycle was constructed (Mn 4+ + Ce 3+ ↔ Mn 3+ + Ce 4+ and Mn 3+ + Co 3+ ↔ Mn 4+ + Co 2+ ). • C1M3C-3% exhibited superior NH 3 -SCR performance and was capable of catalytic combustion of VOCs. • C1M3C-3% demonstrated excellent resistance to moisture and sulfur and can be recirculated by simple calcination (350 ℃, 4 h). • The NH 3 -SCR mechanism of C1M3C-3% was revealed by in-situ DRIFTS. Trace amounts of Co-doped Ce-Mn-based metal oxide catalysts with various applications were synthesized by a simple redox method. When the molar fraction of doped Co was 3%, the catalyst possessed comparatively high contents of adsorbed oxygen species (O ads ), Mn 4+ , Ce 3+ , and Co 3+ , and exhibited promising catalytic performance. C1M3C-3% had a wide denitrification temperature window, achieving 80% NO removal at 87-277 °C and 90% catalytic combustion of toluene at 171 °C (T 90% = 171 °C). Furthermore, the catalyst exhibited satisfactory moisture and sulfur resistance activity and can be regenerated by simple calcination (350 ℃, 4 h). The reason for the high sulfur resistance of C1M3C-3% was investigated in detail and a schematic diagram was provided. The NH 3 -SCR process was revealed to satisfy the L-H mechanism with the assistance of in situ DRIFTS. This work demonstrated that the Co-doped Ce-Mn-based catalyst had the potential for downstream of soot treatment equipment.