Controllable nitrogen introduction into porous carbon with porosity retaining for investigating nitrogen doping effect on SO2 adsorption
Controllable nitrogen introduction into porous carbon with porosity retaining for investigating nitrogen doping effect on SO2 adsorption
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可控氮引入保留孔隙率的多孔碳中研究氮掺杂对 SO2 吸附的影响
DOI：
10.1016/j.cej.2015.12.044
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发表时间：
2016-04-15
影响因子：
15.1
通讯作者：
Wu, Shaohua
中科院分区：
文献类型：
--
作者：
Sun, Fei;Gao, Jihui;Wu, Shaohua
已经证明将氮化学掺杂到碳框架中对于气体分子（例如CO2、SO2、NOR）吸附是有效的。本文报道了一系列通过共组装法制备的氮掺杂多孔炭材料，其掺杂量可控（4.25-10.23%），孔结构稳定（比表面积约1000 m2/g）。基于SO2的独特结构，本文以SO2为探针分子，从实验和计算两个方面独立研究了N掺杂对SO2-碳表面相互作用的影响。结果表明，SO2吸附量与含氮量成正比，含氮量为10.2%的样品对SO2的吸附量最高，达到48.3mg/g，是未掺杂炭的2.95倍。此外，结合文献数据和我们的研究表明，孔结构和N物种在SO2吸附过程中发挥的贡献。对于具有相似孔结构的NPC材料，N含量的增加主要通过增强碳表面不同位置（包括基面和边缘位置）的物理吸附来提高N掺杂碳孔中SO2的吸附面积。密度泛函理论（DFT）计算表明，氮原子本身不能作为SO2吸附的活性位。氮掺杂的作用是改变了碳表面的局域电子密度、碳原子的极性和电荷分布，从而增强了SO2的吸附。(C)© 2016 Elsevier B. V.版权所有。
Chemical doping of nitrogen into carbon framework has been demonstrated effective for gas molecules (e.g. CO2, SO2, NOR) adsorption. Here we report a series of nitrogen-doped porous carbons with controllable doping level (4.25-10.23%) and consistent pore structure (surface area around 1000 m(2)/g) by a co-assembly method. Based on the unique structure, SO2 was used as probe molecule to independently study the N doping effect on the SO2-carbon surface interactions from both experimental and calculation aspects. The results indicate that SO2 adsorption capacities are proportional to the nitrogen contents and the sample with 10.2% nitrogen content gives the highest SO2 adsorption capacity of 48.3 mg/g, 2.95 times higher than non-doped carbon. Moreover, combining the literature data with our studies indicates that both pore structure and N species play a contribution in SO2 adsorption process. For the NPC materials with similar pore structure, the increase of N contents improves the SO2 adsorption area in pores of N doped carbon mainly by enhancing the physisorption on various locations of carbon surface including basal plane and edge positions. Density functional theory (DFT) calculations indicate that nitrogen atom itself cannot serve as active site for SO2 adsorption. The role of nitrogen doping is to remodel the local electronic density, the polarity of carbon atoms as well as charge distribution of carbon surface, which induces the enhanced SO2 adsorption. (C) 2016 Elsevier B.V. All rights reserved.