Impact of Raw Coal on Embedded Mn-Ce/AC Catalysts for NH₃-SCR Denitrification

Abstract

A series of embedded MnO_x-CeO₂/AC catalysts were synthesized from bituminous coal, lignite and ashless coal via the blending method for NH₃ selective catalytic reduction (NH₃-SCR) of NO. The ash-free coal-based YN-AFC catalyst prepared by the solvothermal extraction method exhibited the highest NO conversion, which was 11% greater than YN-AC. YM-AC and YN-AFC catalysts with low ash content have a developed pore structure, which facilitates enhancing the dispersion of the metallic oxides, thereby improving the adsorption capacity of the catalyst for NO and NH₃. In addition, the catalyst with high ash content promotes the formation of Mn₂(CO)₁₀, which contributes to the denitrification reaction, but the inhibition effect of ash is significantly stronger than the promoting effect of Mn₂(CO)₁₀. Moreover, YM-AC and YN-AFC retain more MnO₂ in the sample during the preparation process, resulting in more Mn⁴⁺ being retained in the catalyst to participate in denitrification.