【摘要】 以硝酸锂、正硅酸乙酯等为原料,利用溶胶-凝胶法制备了硅酸锂高温CO2吸附材料,利用XRD考查了制备方法对样品物相的影响;通过程序升温、定温吸附测试对样品的CO2吸附性能进行了表征,并利用原位红外光谱技术初步分析了CO2在硅酸锂表面的吸附过程。结果表明,在硝酸锂-正硅酸乙酯-乙醇共水解体系中引入添加剂柠檬酸,可获得纯度在90%以上的单斜相硅酸锂。所制备的样品在2%CO2-He气氛下,450—500℃温度区间具有较好的吸附性能。低温下CO2吸附在碳酸锂表面,主要以碳酸氢盐形式存在,高温下主要以离子碳酸盐及卧式吸附碳酸盐等形式存在。更多还原

【Abstract】 One of the high-temperature CO2 sorbents lithium orthosilicates (Li4SiO4) was synthesized by using sol-gel method. The structures and the adsorption properties of Li4SiO4 were investigated by XRD, temperature-programming tests, and isothermal tests. In-situ FTIR tests were carried out to analyze the adsorption species and procedure. The results show that high purity (more than 90%) monoclinic Li4SiO4 could be obtained by adding citric acid into the LiNO3-TEOs-Ethanol co-hydrolysis system. Such a Li4SiO4 material shows good CO2 adsorption performance in the atmosphere of 2% CO2 in He within the temperature range of 450—500℃. The major adsorption species on the surfaces of the samples are bicarbonates at lower adsorption temperature, and are ion-type carbonates and horizontal-type carbonates at higher temperature.更多还原