摘要
在“碳达峰、碳中和”这一国家重大战略背景下,CO_(2)捕集已经成为当前重大科技发展方向。固体吸附剂吸附法在CO_(2)的捕集过程中应用广泛,其中SiO_(2)气凝胶具有成本低、合成方法灵活、分离效率高、表面易修饰等优点。然而,SiO_(2)气凝胶材料也存在CO_(2)/N_(2)吸附选择性低,CO_(2)吸附容量有待继续提高等缺陷。为解决上述问题,制备了一种Cu-BTC@SiO_(2)复合气凝胶CO_(2)吸附材料。首先,利用扫描电子显微镜(SEM)、傅里叶红外光谱(FTIR)和氮气吸脱附测试对材料表面化学和孔隙结构进行了系统表征。然后,通过二氧化碳吸附测试对其CO_(2)吸附量、选择性吸附、循环吸附进行了研究。最后,采用理论与试验研究结合的方法,对吸附剂的CO_(2)吸附动力学进行了研究。结果表明:Cu-BTC与SiO_(2)气凝胶具有结构协同作用,与Cu-BTC复合后的SiO_(2)气凝胶不会改变材料的Si-O-Si骨架结构,同时可以保持Cu-BTC的晶体结构不受到损坏。复合材料具有726.431 m^(2)/g的高比表面积,570.781 m^(2)/g的微孔比表面积和0.184 cm^(3)/g的高微孔体积。负载四乙烯五胺(TEPA)后CO_(2)吸附量高达3.20 mmol/g,CO_(2)/N_(2)选择性吸附系数为40.8,循环10次CO_(2)吸附循环,吸附容量仅下降14%,提高了SiO_(2)气凝胶材料的CO_(2)吸附容量和吸附选择性。Avrami分数动力学模型对吸附试验结果拟合相关系数为0.99,且Avrami指数nA为1.9表明吸附剂对CO_(2)的吸附是非均质的多层吸附,既有物理吸附又有化学吸附,且以物理吸附为主。利用具有丰富微孔结构的金属有机骨架材料Cu-BTC与SiO_(2)气凝胶进行复合,使复合材料具有分级微/介孔结构,通过增强分子间作用力(范德华力)来增强材料对CO_(2)的物理吸附;使用TEPA对材料进行浸渍改性,利用有机胺和酸性气体之间的酸碱相互作用来增强材料对CO_(2)的化学吸附。
Under the dual strategic background of“carbon peaking and carbon neutrality”,CO_(2)capture has become an important task at present.Solid adsorbent adsorption is widely used in CO_(2)capture process,among which SiO_(2)aerogel has the advantages of low cost,flex-ible synthesis method,high separation efficiency,easy surface modification,etc.However,SiO_(2)aerogel materials also have some defects,such as low CO_(2)/N_(2)adsorption selectivity and CO_(2)adsorption capacity to be further improved.To address the above issues,this article has prepared a Cu-BTC@SiO_(2)Composite aerogel CO_(2)adsorption material.Firstly,the surface chemistry and pore structure were systematic-ally characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),and nitrogen adsorption and desorption tests.Then,the CO_(2)adsorption capacity,selective adsorption,and cyclic adsorption were studied through carbon dioxide ad-sorption testing.Finally,a combination of theoretical and experimental research was used to study the CO_(2)adsorption kinetics of the ad-sorbent.The results show that the SiO_(2)aerogel compounded with Cu BTC has a high specific surface area of 726.431 m^(2)/g,a specific sur-face area of 570.781 m^(2)/g,and a high microporous volume of 0.184 cm^(3)/g.After loading tetraethylenepentamine(TEPA),the adsorption capacity of CO_(2)is up to 2.95 mmol/g,and the selective adsorption is 40.8,after 10 cycles of CO_(2)adsorption,the adsorption capacity de-creased slightly.Therefore,TEPA-modified Cu-BTC@SiO_(2)composite aerogels can significantly improve the CO_(2)adsorption perform-ance of SiO_(2)aerogels.The metal organic framework material Cu BTC with rich micropore structure is compounded with SiO_(2)aerogel,and is prepared by the sol gel method Cu-BTC@SiO_(2)Composite aerogel to make the composite have hierarchical micro/mesoporous structure and enhance the physical adsorption of CO_(2)by enhancing the intermolecular force(van der Waals force);The material is impregnated with TEPA,and the chemical adsorption of CO_(2)is enhanced by acid-base interaction between organic amine and acid gas.
作者
周刚
杨思奥
王凯丽
董晓素
柳茹林
孙彪
徐翠翠
ZHOU Gang;YANG Siao;WANG Kaili;DONG Xiaosu;LIU Rulin;SUN Biao;XU Cuicui(College of Safety and Environment Engineering,Shandong University of Science and Technology,Qingdao 266590,China;State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology,Qingdao 266590,China)
出处
《煤炭科学技术》
EI
CAS
CSCD
北大核心
2024年第7期235-247,共13页
Coal Science and Technology
基金
国家自然科学基金面上资助项目(52274215)
山东省自然科学基金资助项目(ZR2021QE237)。
