Low-Temperature Selective Catalytic Reduction of NO_x on MnO₂ Octahedral Molecular Sieves (OMS-2) Doped with Co

Abstract

To improve NO conversion and sulfur resistance of low-temperature NO-CO selective catalytic reduction (SCR), it is urgent to seek new catalyst materials. Herein, using the pre-doping method, Cox-OMS-2 with different ratios of cobalt (Co) was obtained during hydrothermal synthesis of OMS-2 molecular sieves (where x represents the doping ratio of Co, i.e., x = 0.1, 0.2, 0.3, 0.4). Co was found to very efficiently intercalate into the crystal structure of OMS-2. Co and Mn work together to promote the selective reduction reaction of NOx;; the NO conversion of Co0.3-OMS-2 was the highest among all samples. Specifically, NO conversion at 50 °C increased from 72% for undoped OMS-2 to 90% for Co0.3-OMS-2. Moreover, due to the incorporation of Co, the latter also showed better sulfur resistance.

Keywords

• denitrification
• CO-SCR
• OMS-2
• sulfur resistance
• cobalt doping