A novel CNTs functionalized CeO2/CNTs-GAC catalyst with high NO conversion and SO2 tolerance for low temperature selective catalytic reduction of NO by NH3

Low-temperature selective catalytic reduction of NOx by NH3 (NH3-SCR) for diminishing SO2 poisoning remains an issue in flue gas denitrification (DeNOx). Herein, A novel CNTs functionalized low temperature NH3-SCR catalyst CeO2/CNTs-GAC was prepared, which showed high NO conversion activity (100% at 150 degrees C) and SO2 resistance. The addition of CNTs restrained SO2 adsorption but improved the selective adsorption of NO, which restricted the deposition of (NH4)2SO4 and/or Ce2(SO4)3, and resulted in high SO2 resistance. The addition of CNTs facilitated the diffusion and transportation of NH3 and NO, and the electron transfer on CeO2/ CNTs-GAC, leading to higher content of Ce3+ and adsorbed O species on the CeO2/CNTs-GAC surface and promoted formation of surface-adsorbed oxygen OA. Therefore, CeO2/CNTs-GAC provided abundant NO adsorption and activation sites, facilitating fast SCR reaction and enhancing the NH3-SCR reaction. The proposed CeO2/CNTs-GAC catalyst exhibited higher NH3-SCR activity, N2 selectivity, catalytic durability and SO2 resistance than CeO2/GAC.

Automated summary

The newly prepared CeO2/CNTs-GAC catalyst exhibits high efficiency in low-temperature selective catalytic reduction of NOx by NH3 and excellent SO2 resistance. The addition of CNTs enhances the catalytic performance, inhibits SO2 adsorption, and promotes the formation of oxygen oxidation species.