ZHANG T, WANG B B, LI Y.Preparation of stalk-based nitrogen-doped porous carbon and its CO₂ adsorption and CO₂/N₂ separation properties[J].Journal of Henan Polytechnic University(Natural Science) ,2022,41(6):174-180.

doi:10.16186/j.cnki.1673-9787.2020090060

Received:2020/09/14

Revised:2021/01/07

Published:2022/11/25

Preparation of stalk-based nitrogen-doped porous carbon and its CO₂ adsorption and CO₂/N₂ separation properties

ZHANG Tao1, WANG Binbin1, LI Yao2,3

1.School of Materials Science and Engineering，Henan Polytechnic University，Jiaozuo 454000，Henan，China；2.School of Safety Science and Engineering，Henan Polytechnic University，Jiaozuo 454000，Henan，China；3.Key Laboratory of Gas Geology and Gas Control of Henan Province，Jiaozuo 454000，Henan，China

Abstract:In order to address the increasing amount of CO₂ in the atmosphere，adopting corn stalks as raw，a series of nitrogen-doped porous carbon samples（CPH-0，CPH-0.5 and CPH-1）with well-developed porous structure were prepared by hydrothermal carbonization and KOH activation treatment with the control of KOH activation intensity.According to characterization of scanning electron microscopy（SEM）and transmission electron microscopy（TEM），N₂ adsorption-desorption isotherm test and elemental analysis，the relationship between porous structure development content and KOH activation intensity could be obtained.By analyzing CO₂ adsorption test，it could be known that under low pressure（<15 kPa），the CO₂ adsorption capacity was mainly influenced by N content，while under ambient pressure （100 kPa），the CO₂ adsorption capacity was determined by ultra-micropore（<100 kPa）volume.Sample CPH-0 had the highest content and showed excellent CO₂ adsorption capacity at low pressure range.Sample CPH-0.5 had the largest ultra-micropore volume，and showed a CO₂ adsorption capacity as high as 3.97 mmol/g under the 25 °C and 100 kPa，as well as good CO₂/N₂ selectivity and excellent cycling stability.The porous carbon prepared by this method had a broad application prospect in CO₂ adsorption and CO₂/N₂ separation.

Key words:corn stalk;porous carbon;hydrothermal carbonization;KOH activation;CO adsorption;CO/N separation

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