Mechanism of enhancing NH3-SCR performance of Mn-Ce/AC catalyst by the structure regulation of activated carbon with calcite in coal

To elucidate the effect of calcite-regulated activated carbon (AC) structure on low-temperature denitrification performance of SCR catalysts, this work prepared a series of Mn-Ce/De-AC- x CaCO 3 ( x is the calcite content in coal) catalysts were prepared by the incipient wetness impregnation method, followed by acid washing to remove calcium-containing minerals. Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity. Specifically, NO conversion increased from 88.3% of Mn-Ce/De-AC to 91.7% of Mn-Ce/De-AC-1CaCO 3 (210 °C). The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn 4+ content and Ce 4+ /Ce 3+ ratio, an abundance of chemisorbed oxygen and acidic sites, which could strengthen the SCR reaction pathways (richer NH 3 activated species and bidentate nitrate active species). Therefore, NO removal is enhanced.