物理化学学报 >> 2006, Vol. 22 >> Issue (07): 860-863.doi: 10.3866/PKU.WHXB20060718

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Na 掺杂对硅酸锂吸收CO2性能的影响

王银杰;其鲁;代克化   

  1. 北京理工大学材料科学与工程学院, 北京 100081; 北京大学化学与分子工程学院应用化学系, 北京 100871
  • 收稿日期:2005-12-26 修回日期:2006-02-23 发布日期:2006-06-27
  • 通讯作者: 王银杰 E-mail:wyj@bit.edu.cn

Effect of Na-doping on CO2 Absorption of Li4SiO4

WANG Yin-Jie;QI Lu;DAI Ke-Hua   

  1. School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China; Department of Applied Chemistry, College of Chemistry & Molecular Engineering, Peking University, Beijing 100871, P. R. China
  • Received:2005-12-26 Revised:2006-02-23 Published:2006-06-27

摘要: 通过高温固相反应法, 在添加不同比例Na2CO3的条件下, 合成出一系列可在高温500~750 ℃之间直接吸收CO2的硅酸锂材料. 利用扫描电子显微镜、X射线粉末衍射仪分别观察和评价了合成材料的表面形貌与结构特征, 用热重分析仪测量了硅酸锂材料的CO2吸收性能. 实验结果表明, 通过适量Na元素的掺杂, 能够提高硅酸锂材料吸收CO2的性能, 当Na2CO3的添加量x=0.02时, 合成的硅酸锂材料在CO2气氛下, 于700 ℃恒温保持约15 min即可达到吸收平衡, 材料的吸收量为(46±0.6)%(w), 与未经掺杂的材料相比, 吸收容量有所提高. 此外, 气氛中CO2的浓度对材料吸收CO2的速率有较大影响.

关键词: 硅酸锂, 吸收, CO2, 掺杂, TG

Abstract: Sodium-doped lithium silicate as CO2 absorbent at 500 ℃ to 750 ℃ was prepared by high-temperature solid-state reaction. The influence of sodium doping on the crystal structure of the absorbent was studied by X-ray diffraction (XRD). The microscopic morphologies of the absorbents were observed by scanning electron microscopy (SEM). The CO2-absorption capacities were measured by a thermogravimetric analyzer, which showed that sodium doping could improve the CO2-absorption ability of lithium silicate. It was found that the absorbent possessed the best performance when n(SiO2):n(Li2CO3):n(Na2CO3)=1:1.96:0.04. The maximum amount of CO2 absorption arrives at (46±0.6)%(w) in CO2 atmosphere at 700 ℃ within 15 min. Moreover, the CO2 concentration in gas phase influences the rate of CO2 absorption.

Key words: Lithium silicate, Absorption, Carbon dioxide, Doping, TG