A novel strategy for efficient utilization of manganese tailings: High SO2 resistance SCR catalyst preparation and faujasite zeolite synthesis

Herein, a core-shell structure SiO2@Mn catalyst was successfully synthesized from manganese tailings for NO removal through selective catalytic reduction with ammonia at low temperature. In the presence of 10 % H2O and 100 ppm SO2, the SiO2@Mn catalyst exhibited excellent catalytic activity of 85 % NO conversion at 225 degrees C. This special core-shell was constructed by inert nano-SiO2 particles, which grew and encapsulated on the surface of manganese oxide, inhibiting the reaction between SO2 with MnOx and thus improving the SO2 resistance. Furthermore, a filter residue was generated in the process of catalysts preparation. Under proper hydrothermal conditions, the residue comprising of Si, Al, and O was used to synthesize high-crystallinity X-type zeolite. This process fully utilized manganese tailings and inspired for Mn-based catalysts design and X-type zeolite prepa- ration, realizing the dual benefits of atmosphere purification and solid waste disposal.

Automated summary

A core-shell structure SiO2@Mn catalyst was successfully synthesized from manganese tailings for selective catalytic reduction of NO with ammonia at low temperature. The catalyst exhibited excellent catalytic activity of 85% NO conversion at 225 degrees C in the presence of 10% H2O and 100 ppm SO2. The core-shell structure, composed of inert nano-SiO2 particles encapsulated on the surface of manganese oxide, effectively improved the SO2 resistance by inhibiting the reaction between SO2 and MnOx. Additionally, a filter residue generated during catalyst preparation was utilized to synthesize high-crystallinity X-type zeolite, achieving the dual benefits of atmosphere purification and solid waste disposal.