高岭石基介孔复合材料的二氧化碳吸附性能

碳排放量的快速增长所引起的全球气候变暖问题越来越受到各国的关注,因此研发制备可行高效的二氧化碳(CO₂)捕获材料具有极其重要的意义。本文以高岭石为原材料,采用煅烧-碱活化-酸刻蚀的方法,制备出介孔氧化硅载体(KNH),再将KNH经过五乙烯六胺(PEHA)修饰后制备出介孔复合材料(KNH-PEHA)。通过X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、N₂物理吸附等方法对样品进行表征,并进一步对样品进行CO₂吸附性能研究。结果表明,PEHA的浸渍修饰并未改变载体的结构,但显著提高了介孔复合材料对CO₂的吸附能力。吸附温度为25 ℃,KNH的CO₂吸附量为147.39 cm³/g,而PEHA质量分数为30%的KNH(KNH-P-30)平衡时的CO₂吸附量达到389 cm³/g,远高于未经PEHA修饰的KNH的吸附量,同时提出了该固体吸附剂对CO₂的吸附机理,为高岭石在气体吸附领域的应用提供一个新思路。

Carbon Dioxide Adsorption Property of Kaolinite-Based Mesoporous Composites

The problem of global warming caused by the rapid growth of carbon emissions has attracted more and more attention in all countries, so it is of great importance to develop feasible CO₂ capture materials. In this paper, kaolinite is used as raw material, to prepare mesoporous silica carrier (KNH) with the method of calcination-alkali activation-acid etching. Then the pentaethylenehexaamine (PEHA) functionalized mesoporous silica (KNH-PEHA) was synthesized via impregnation. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and N₂ adsorption-desorption isotherms treated by BET (Brunauer-Emmett-Teller) analysis. And the solid adsorbent is also used to study the adsorption property of carbon dioxide (CO₂). The results indicate that the structure of PEHA-loaded KNH is not changed, but its carbon dioxide adsorption capacity is improved. When the adsorption temperature is 25 ℃, the CO₂ adsorption capacity of KNH is 147.39 cm³/g, and the CO₂ adsorption capacity of KNH (KNH-P-30) with a mass percentage of PEHA of 30% reaches 389 cm³/g, which is much higher than that without PEHA modified KNH adsorption. At the same time, it express the adsorption mechanism of the solid adsorbent for CO₂, which provides a new idea for the application of kaolinite in the field of gas adsorption.