活性焦孔结构与含氮官能团协同构筑对低温 NO 还原特性影响

Low-temperature NH₃ -SCR is an important technology choice for flue gas denitrification in non-electricity industries with low exhaust temperature, and low - cost carbon materials with good structural tunability are one of the most promising low - temperature NH₃ -SCR catalysts, but face the bottleneck of low denitrification efficiency. In this paper, based on a one - step catalytic activation process, activated coke catalysts with typical pore configurations and nitrogen-containing functional groups were prepared from low-cost and large-volume Jundong coal as raw materials, and the effects of activated coke pore configurations and surface functional groups on the low- temperature NH₃ - SCR under different flue gas conditions were investigated. The results showed that both graded pores and nitrogen-containing functional groups have significant effects on NH₃ -SCR, and the nitrogen-doped graded-porous activated coke with both graded pores and nitrogen-containing functional groups has the optimal performance of NH₃ -SCR due to the simultaneous improvement of the mass transfer channels and reaction kinetics, and its denitrification efficiency reaches as high as 83.5% under the condition of 160 ℃ . The enhancement effects of graded pores and nitrogen-containing functional groups on the NH₃ -SCR performance are more obvious in the presence of SO₂ or H₂ O, and the denitrification efficiency of microporous activated coke decays from 39. 6% to 13. 8% and 34.9%, whereas the denitrification efficiency of nitrogen - doped graded - porous coke improves to 86. 4% and 86. 7%, respectively. This may be related to the synergistic effect between different flue gas components enhanced by the functionalized graded pore environment. In this study, the dependence between the performance of carbon-based low-temperature NH₃ -SCR and the physicochemical structure of the carbon materials was investigated, which provides a new idea for the development of high-performance carbon-based low-temperature NH₃ -SCR technology.