The effects of nitrogen functional groups and narrow micropore sizes on CO2 adsorption onto N-doped biomass-based porous carbon under different pressure
The effects of nitrogen functional groups and narrow micropore sizes on CO2 adsorption onto N-doped biomass-based porous carbon under different pressure
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不同压力下氮官能团和窄微孔尺寸对氮掺杂生物质基多孔碳吸附CO2的影响
DOI：
10.1016/j.micromeso.2021.111404
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发表时间：
2021-09-06
影响因子：
5.2
通讯作者：
Norinaga, Koyo
中科院分区：
文献类型：
--
作者：
Luo, Junying;Liu, Baogen;Norinaga, Koyo
生物质衍生的氮掺杂多孔碳由于其良好的二氧化碳/氮气选择性和优异的二氧化碳吸附性能，已被证明是一种有前途的吸附材料。然而，许多研究人员只是研究了氮基团或窄微孔（小于0.7纳米）在1巴压力下对二氧化碳吸收的影响，而忽略了不同压力的作用。在本研究中，通过尿素辅助水热法和氢氧化钾活化制备了一种源自桉树皮的、具有高二氧化碳吸附能力的有前途的多孔碳。所获得的多孔碳主要为微孔结构，且氮含量丰富。在这些材料中，在1巴压力下，NPC700在25℃和0℃时分别表现出4.20毫摩尔/克和6.98毫摩尔/克的高二氧化碳吸附量。基于巨正则蒙特卡罗（GCMC）模拟，计算了不同孔径（0.6 - 2.0纳米）的石墨狭缝孔以及氮掺杂官能团（吡啶氮、吡咯氮和石墨氮）上的吸附密度和吸附能。结果表明，在相对低压（0 - 0.16巴）下，氮官能团对二氧化碳吸附量起着至关重要的作用。在相对高压（0.16 - 1巴）下，窄微孔体积决定了二氧化碳的吸收量。
The biomass-derived N-doped porous carbons have been proved promising adsorbent material, due to their good CO2/N-2 selectivity and excellent CO2 adsorption performance. However, many researchers simply studied the effect of nitrogen groups or narrow micropores (less than 0.7 nm) on CO2 uptake at 1 bar and ignored the role of different pressures. In this study, a promising porous carbon derived from eucalyptus bark with high CO2 adsorption capacity was prepared by urea-assisted hydrothermal and KOH activation. The obtained porous carbons were found to be mainly microporous and showed rich nitrogen content. Among the materials, at 1 bar, NPC700 exhibits high CO2 adsorption of 4.20 mmol/g and 6.98 mmol/g at 25 degrees C and 0 degrees C, respectively. Based on Grand canonical Monte Carlo (GCMC) simulation, the adsorption density and adsorption energy on graphite slit pore with different pore sizes (0.6-2.0 nm) and N-doped functional groups (pyridinic-N, pyrrole-N and graphitic-N) were calculated. And the results showed that the nitrogen functional groups played a crucial contribution on CO2 adsorption capacity at relative low pressure (0-0.16 bar). In the case of relative high pressure (0.16-1 bar), the narrow micropores volume determined the CO2 uptake capacity.