北京大学学报(自然科学版)

K元素的掺杂对锆酸锂材料吸收CO2性能的影响

王银杰1,2,其鲁2,杜柯2,闻雷2   

  1. 1北京理工大学电子工程系,北京,100081;2北京大学化学与分子工程学院应用化学系,北京,100871,E-mail: qilu@pku.edu.cn
  • 收稿日期:2004-08-23 出版日期:2005-07-20 发布日期:2005-07-20

Effect of Doping K Element on Properties of Lithium Zirconate as CO2-absorbent

WANG Yinjie1, 2, QI Lu2, DU Ke2, WEN Lei2   

  1. 1Department Electronic Engineering, Beijing Institute of Technology, Beijing, 100081; 2Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871,E-mail:qilu@pku.edu.cn
  • Received:2004-08-23 Online:2005-07-20 Published:2005-07-20

摘要: 以纳米级单斜相ZrO2为反应物,采用高温固相合成法在K元素掺杂的情况下,制备了一系列可在高温460~650℃下直接吸收CO2的锆酸锂材料——Li2K2xZrO3(0≤x≤0.4)。采用扫描电镜(SEM)、X-射线衍射仪(XRD)以及热重分析仪(TG)分别进行了形貌、结构以及吸收CO2性能的分析。实验结果表明,通过适量K元素的掺杂,能明显改善材料吸收CO2的性能,当K2CO3的添加量x=0.03时,制备的材料具有较快的吸收速度和较好的吸收容量,在500℃、20% CO2(80%空气)的气氛下保持160min即可达到吸收平衡,吸收量可达(25±0.6)%(wt),而且材料的循环性能也较好。

关键词: 锆酸锂, 吸收, CO2, K2CO3, 掺杂

Abstract: With nanometer-sized monoclinic ZrO2, lithium carbonate, and potassium carbonate as starting materials, potassium-doped lithium zirconate Li2K2xZrO3 (0≤x≤0.4) absorbents are prepared by high-temperature solid-state reaction. The influence of doping potassium on the crystal structure of the prepared absorbents is studied by comparison of their XRD patterns. The microscopic morphologies of absorbents with different x were viewed by a sanning electron microscopy. Their CO2 absorption abilities were measured with a thermogravimetric analyzer. The experimental results show that doping potassium can significantly improve the CO2 absorption ability of lithium zirconate. It is found that Li2K2xZrO3 absorbent with x=0.03 possesses the best performance. As much as (25±0.6)% (wt) of CO2 was absorbed by such an absorbent from an atmosphere consisting of 20% of CO2 plus 80% of air at 500℃ within 160min. After 18 absorption-desorption cycles this absorbent lost only 1.1% of its CO2-absorption capacity. Since no remarkable change in particle size is observed, the performance improvement might be attributed to the creation of lattice defects in the lithium zirconate crystals by doping potassium.

Key words: lithium zirconate, absorption, CO2, K2CO3, doping

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