摘要
胺基功能化吸附材料具有优异的CO_(2)吸附选择性和抗水能力,在CO_(2)捕集领域有着巨大应用潜力.然而,传统胺基功能化吸附材料与CO_(2)分子间的强相互作用使得再生能耗和吸附性能难以同步优化,限制了其实际应用.本研究提出了孔径匹配的胺基功能化策略,在保证低再生能耗的同时大幅提升材料的CO_(2)吸附能力.基于该策略所开发的三乙烯四胺(triethylenetetramine,TETA)功能化UIO-66吸附材料(TETA@UIO-66),吸附容量相比UIO-66提高了84%,吸附选择性提高了452%,且吸附速率常数提高了75%.然而其等量吸附热仅为35 kJ mol^(−1).通过理论计算结合原位表征揭示了其CO_(2)物理吸附机理.本研究不仅为胺基功能化材料扩展了应用前景,还为构建高效低能耗的CO_(2)吸附材料提供了新的思路.
Developing adsorbents with efficient carbon dioxide(CO_(2))capture performance and low regeneration energy consumption is critical for reducing carbon emissions from fossil fuels.Metal–organic frameworks(MOFs)exhibit excellent CO_(2)adsorption capacity owing to their large specific surface area and open metal sites.However,water or other impurities present in the coal-fired flue gas can enter the pores of MOFs and compete with CO_(2)adsorption,reducing the CO_(2)adsorption capacity.Amine functionalization is a cost-effective strategy to efficiently improve the water resistance and CO_(2)adsorption capacity of MOFs.However,strong chemical bonds between amine groups and CO_(2)molecules hinder adsorbent regeneration.To find the“sweet spot”between adsorption capacity and regeneration energy consumption,it is essential to modulate the interaction forces between CO_(2)molecules and adsorbents.This study proposes a pore-matching amine functionalization strategy that precisely matches amine molecules to MOF pore sizes.This strategy effectively modulates the interaction between CO_(2)molecules and amine-functionalized MOFs by strengthening van der Waals interactions within MOF pores.Based on this,a triethylenetetramine(TETA)-functionalized zirconium 1,4-dicarboxybenzene MOF(UIO-66)adsorbent(TETA@UIO-66)was developed.The CO_(2)uptake by TETA@UIO-66 was 1.66 mmol g^(−1) at 25℃and 100 kPa,which was 1.84-fold higher than that by pristine UIO-66.The adsorption–desorption cycling results showed that the adsorption capacity of TETA@UIO-66 decreased by 11.1%after 10 cycles,which was probably owing to its inability to fully restore the original adsorption performance at 100 kPa.In addition,the blockage or collapse of the UIO-66 pore structure during repeated cycles might impact the cycling performance.The CO_(2):N_(2)(15:85)adsorption selectivity of TETA@UIO-66 was 5.12-fold higher than that of pristine UIO-66 under the same conditions.Kinetic analysis revealed that the adsorption process of TETA@UIO-66 followed the pseudo-second-order kinetic model,with an adsorption rate constant that is 1.75-fold higher than that of pristine UIO-66.The equivalent heat of adsorption was 35 kJ mol^(−1).The CO_(2)adsorption and separation capabilities of TETA@UIO-66 were improved with CO_(2)/N_(2) selectivity increasing from 8.45 to 43.26 at 25℃and 100 kPa,representing a 5.12-fold enhancement over pristine UIO-66.The density functional theory(DFT)was used to predict the CO_(2)binding sites.CO_(2)molecules are stably adsorbed by TETA@UIO-66 owing to strong interactions with N atoms,further reducing the energy of the material from−27.02 to−32.12 kJ mol^(−1),which is 5.1 kJ mol^(−1) lower than that of the stable pristine UIO-66.The adsorption mechanism was further elucidated via in situ diffuse infrared reflectance spectroscopy(DRIFTS)characterization.The characteristic double peaks of primary amines were present in TETA@UIO-66 throughout the adsorption process,indicating that no chemical reaction occurred between TETA@UIO-66 and CO_(2).These findings suggest that TETA@UIO-66 follows a physical adsorption mechanism.In summary,this study introduces a novel pore-matching amine-functionalized strategy by developing TETA@UIO-66 for efficient CO_(2)adsorption with low energy consumption.TETA@UIO-66 exhibits high adsorption capacity,high adsorption rate,good adsorption selectivity,and excellent stability.DFT calculations and in situ DRIFTS results elucidate the synergistic mechanism of CO_(2)adsorption between TETA molecules and UIO-66.This work expands the potential of amine-functionalized materials and broadens the feasible application prospects of CO_(2)adsorption.
作者
沈遥
鲁恒霞
杨雄威
叶杰旭
赵景开
张士汉
高翔
Yao Shen;Hengxia Lu;Xiongwei Yang;Jiexu Ye;Jingkai Zhao;Shihan Zhang;Xiang Gao(Science and Education Integration College of Energy and Carbon Neutralization,Zhejiang University of Technology,Hangzhou 310014,China;College of Environment,Zhejiang University of Technology,Hangzhou 310014,China)
出处
《科学通报》
北大核心
2025年第14期2095-2103,共9页
Chinese Science Bulletin
基金
浙江省自然科学基金(LDT23E06015B06)
浙江省“尖兵”研发攻关计划(2022C03040)
国家自然科学基金(U23A20677,22022610,52400137)
中国博士后科学基金(2024T170805)
国家资助博士后研究人员计划(GZC20232363)资助。
