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林产化学与工业 ›› 2021, Vol. 41 ›› Issue (2): 1-9.doi: 10.3969/j.issn.0253-2417.2021.02.001

• 重点研发专栏 • 上一篇    下一篇

落叶松基氮掺杂泡沫炭的制备及其CO2吸附性能研究

张宇航1, 应浩2, 李伟1, 马春慧1, 罗沙1, 刘守新1,*()   

  1. 1. 东北林业大学, 生物质材料科学与技术教育部重点实验室, 黑龙江 哈尔滨 150040
    2. 中国林业科学研究院 林产化学工业研究所, 江苏 南京 210042
  • 收稿日期:2020-11-18 出版日期:2021-04-28 发布日期:2021-05-08
  • 通讯作者: 刘守新 E-mail:liushouxin@126.com
  • 作者简介:刘守新, 教授, 博士生导师, 研究领域为功能炭材料以及光催化材料; E-mail: liushouxin@126.com
    张宇航(1997-), 男, 内蒙古呼伦贝尔人, 硕士生, 研究方向为多孔炭材料的制备及CO2吸附应用
  • 基金资助:
    国家重点研发计划资助项目(2017YFD0601006);国家自然科学基金资助项目(31971601)

Preparation and CO2 Adsorption Performance of Larch-based N-doped Carbon Foam

Yuhang ZHANG1, Hao YING2, Wei LI1, Chunhui MA1, Sha LUO1, Shouxin LIU1,*()   

  1. 1. Key Laboratory of Bio-Based Material Science & Technology of Ministry of Education, Northeast Forestry University, Harbin 150040, China
    2. Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing 210042, China
  • Received:2020-11-18 Online:2021-04-28 Published:2021-05-08
  • Contact: Shouxin LIU E-mail:liushouxin@126.com

摘要:

以落叶松木屑为原料,尿素为氮源,采用苯酚液化-物理发泡-活化工艺制备了落叶松基氮掺杂泡沫炭。通过SEM、XRD、XPS、TG和N2吸附-脱附等温线对材料的形貌、表面化学性质和孔结构进行表征,并测试了材料的CO2吸附容量和CO2/N2吸附选择性,考察了氮掺杂量及活化温度对CO2吸附性能的影响。研究结果表明:泡沫炭材料具有石墨层无序堆积的晶型结构,其无序性随着活化温度的升高而提高,氮掺杂会使其孔泡尺寸变小并降低其热稳定性;氮掺杂泡沫炭主要为微孔结构,微孔孔容占比最高可达95.83%。在活化温度为900℃、尿素掺杂量为4、6和8 g的条件下制备氮掺杂泡沫炭(NCF-4-900、NCF-6-900和NCF-8-900)的微孔孔径主要集中在0.50、0.81和1.26 nm,介孔孔径集中在3.85 nm左右;材料的掺杂氮以3种形式存在,活化温度为700和800℃时主要为吡啶型氮(N-6)和吡咯型氮(N-5);当活化温度达到900℃时部分N-5和N-6转化为热稳定性更好的四元型氮(N-Q),其中吡咯型氮含量最高;随着活化温度的升高,材料的CO2吸附容量提高,在25℃和100 kPa下NCF-8-900具有最高的吸附容量(3.19 mmol/g)和CO2/N2吸附选择性(118.63)。

关键词: 尿素, 泡沫炭, CO2吸附, 孔结构, 吸附选择性

Abstract:

Larch-based N-doped carbon foam was prepared with larch sawdust as carbon source and urea as nitrogen source via phenol liquefaction-physical foaming-activation method. Morphology, surface chemical properties and pore structure of the prepared carbon foams were analyzed by SEM, XRD, XPS, TG and N2 adsorption-desorption isotherm. CO2 adsorption capacity and CO2/N2 adsorption selectivity of the materials were tested as well. Effects of nitrogen doping and activation temperature on CO2 adsorption performance were investigated. The results showed that carbon foam had the crystal structure of disordered stacking of graphene layers, and its disorder increased with the rise of activation temperature. Nitrogen doping reduces the size of cell and thermal stability. Nitrogen-doped carbon foam exhibited typical microporous structure with the maximum micropore content of 95.83%. The microporous pore size of nitrogen-doped carbon foams(NCF-4-900, NCF-6-900 and NCF-8-900) which were prepared under the conditions of activation temperature of 900 ℃ and urea doping amounts of 4, 6 and 8 g were mainly concentrated at 0.50, 0.81 and 1.26 nm, and the mesoporous pore size was concentrated in about 3.85 nm.The materials contained 3 types of nitrogen and they were mainly pyridine nitrogen(N-6) and pyrrole nitrogen(N-5) when the activation temperatures were 700 and 800 ℃. With the activation temperature reaching 900 ℃, some N-5 and N-6 were transformed into quaternary nitrogen(N-Q) with better thermal stability, and pyrrolic N was dominant. CO2 adsorption capacity increased with the rise of activation temperature. NCF-8-900 had the highest adsorption capacity(up to 3.19 mmol/g at 25 ℃ and 100 kPa) and excellent CO2/N2 adsorption selectivity of 118.63.

Key words: urea, carbon foam, CO2 adsorption, pore structure, adsorption selectivity

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