利用煤焦油中酚类物质Stöber法制备碳纳米球用于CO_(2)吸附

Coal tar phenol-based carbon nanosphere prepared by Stöber method for adsorption of CO_(2)

煤焦油的排放和直接利用会造成严重的环境污染,开发高附加值材料的绿色合成方法及应用是煤焦油利用的关键。本文采用Stöber法以间苯二酚和中低温煤焦油为碳源与甲醛聚合制备了多孔碳纳米球CO_(2)吸附剂,通过扫描电子显微镜、N2吸附-脱附测试、傅里叶变换红外吸收光谱、X射线衍射等手段对样品进行测试和分析。考察了预聚温度、水热温度和煤焦油添加量对碳纳米球的孔结构和CO_(2)吸附性能的影响。预聚温度为60℃、水热温度为200℃时,产物具有最优异的比表面积和CO_(2)吸附性能。C_(1)-R_(1)-RT-200吸附剂的比表面积达到787m^(2)/g,CO_(2)最大吸附量为4.64mmol/g。当煤焦油占总投料质量的50%~76%时,产物的CO_(2)吸附性能较好,优于纯的间苯二酚模型化合物。所制备的多孔碳纳米球的CO_(2)吸附等温线可以很好地吻合Langmuir等温线模型,说明多孔碳纳米球对CO_(2)的吸附为单分子层吸附。

Emission and direct utilization of coal tar caused severe environmental pollution.Thus,developing a green synthesis method and application of high-valued materials is critical to the utilization of coal tar.Herein,we successfully fabricated porous carbon nanosphere as CO_(2)adsorbent using resorcinol and medium-and low-temperature coal tar as carbon sources to polymerize with formaldehyde via the Stöber method.The samples were tested and analyzed by scanning electron microscopy,N2 adsorption-desorption,Fourier transform infrared absorption spectroscopy,and X-ray diffraction.We investigated the effects of pre-polymerization temperature,hydrothermal temperature,and coal tar ratio on the pore structure and adsorption performance of CO_(2).When the pre-polymerization and hydrothermal temperatures were 60℃and 200℃,respectively,the product had the highest specific surface and CO_(2)adsorption capacity.The specific surface area of the C_(1)-R_(1)-RT-200 adsorbent was 787m^(2)/g with the CO_(2)adsorption capacity of 4.64mmol/g.The product had better CO_(2)adsorption capacity when the mass fraction of coal tar was 50%-76%,which was much higher than that synthesized using the pure resorcinol model compounds.The CO_(2)adsorption isotherm of the prepared porous carbon nanospheres matched well with the Langmuir isotherm model,indicating that the CO_(2)adsorption of the porous carbon nanospheres was a monolayer adsorption.Our work could contribute to developing the green synthesis method for coal tar-based CO_(2)adsorbents.