作者：缪应菊^1,2,3, 李琳^1,2, 缪应纯⁴, 陕绍云³

作者单位：1. 六盘水师范学院化学与材料工程学院, 贵州 六盘水 553004;
2. 贵州省煤炭洁净利用重点实验室, 贵州 六盘水 553004;
3. 昆明理工大学化学工程学院, 云南 昆明 650500;
4. 曲靖师范学院化学与环境科学学院, 云南 曲靖 655000

关键词：粉煤灰;二氧化硅气凝胶;物理表征;CO₂捕集

摘要：

以六盘水高硅粉煤灰为原料，联合溶胶-凝胶工艺和冷冻干燥技术制备二氧化硅气凝胶，采用TG、XRF、FTIR、TEM、N₂吸附脱附等对所制备的二氧化硅气凝胶进行表征并研究其在常温常压下的CO₂捕集性能。结果表明：所制备的二氧化硅气凝胶热稳定性良好，纯度高(99.586%)，由5~10 nm的二氧化硅纳米颗粒组成，兼具微孔、介孔的复合孔结构，微孔区比表面积为553.73 m²/g，介孔区比表面积455.47 m²/g；常温常压下CO₂饱和吸附容量为1.22 mmol/g，CO₂等量吸附热在38.7~39.1 kJ/mol之间，CO₂/N₂选择性为28.44。

Characterization of silica aerogels synthesized from high-Si fly ash and its application in CO₂ capture
MIAO Yingju^1,2,3, LI Lin^1,2, MIAO Yingchun⁴, SHAN Shaoyun³
1. School of Chemistry and Materials Engineering, Liupanshui Normal University, Liupanshui 553004, China;
2. Guizhou Provincial Key Laboratory of Coal Clean Utilization, Liupanshui 553004, China;
3. Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650500, China;
4. College of Chemistry and Environmental Science, Qujing Normal University, Qujing 655000, China
Abstract: High-Si fly ash from Liupanshui were used as raw materials to synthesize silica aerogels via sol-gel process and freeze-drying technology, TG, XRF, FTIR, TEM, as well as N₂ adsorption and desorption were used to characterize the silica aerogels. The resulting aerogels had good thermal stability and high purity (99.586%), and were composed of 5-10 nm silica nanoparticles with a composite pore structure of micropore and mesoporous. The specific surface areas of the micropore district and the mesoporous district were 553.73 m²/g and 455.47 m²/g, respectively. The as-synthesized aerogels were tested for CO₂ sorption at ambient temperature and pressure, displaying maximum CO₂ adsorption capacities of about 1.22 mmol/g via a physisorption. Furthermore, the isosteric heat of adsorption was at the range of 38.7-39.1 kJ/mol and the selectivity for CO₂/N₂ was 28.44.
Keywords: fly ash;silica aerogels;physical characterization;CO₂ capture
2020, 46(5):51-56,64  收稿日期: 2019-11-20;收到修改稿日期: 2020-01-05
基金项目: 国家自然科学基金(21766016)；贵州省科学技术基金([2018]2334)；曲靖师范学院应用基础研究(2077360172)；云南省青年拔尖人才项目(YNWR-QNBJ-2018-198)；贵州省煤炭洁净利用重点实验室（黔科合平台人才[2020]2001）
作者简介: 缪应菊(1983-),女,云南宣威市人,副教授,博士,主要从事固体废弃物的资源化利用及无害化处置
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