Cu-BTC基改性生物焦复合吸附剂的脱汞性能及机理  

Hg^(0) removal performance and mechanism of Cu-BTC/FeCu-BC composite adsorbent

作　　者：贺玲 冯有祥 余靖翔 程鹏 聂浩田 武亚文 闫祺祯 张震 贾里 HE Ling;FENG Youxiang;YU Jingxiang;CHENG Peng;NIE Haotian;WU Yawen;YAN Qizhen;ZHANG Zhen;JIA Li(College of Electrical and Power Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学电气与动力工程学院,山西太原030024

出　　处：《煤炭学报》2025年第3期1747-1759,共13页Journal of China Coal Society

基　　金：山西省基础研究计划资助项目(202303021212043,20210302124449);山西省研究生科研创新资助项目(2023KY210)。

摘　　要：为了获得经济高效的烟气脱汞剂,基于掺杂Fe/Cu多元金属的改性生物焦与作为金属有机骨架材料(Metal-organicFrameworks,MOFs)的Cu-BTC两者均含有不饱和金属中心与含氧官能团的基础特性进行结构设计,利用原位生长法制备MOFs基改性生物焦复合吸附剂。在获得样品Hg0脱除特性的基础上,针对Cu-BTC与改性生物焦以及所含各类型活性中心之间的耦合机理及协同机制进行了研究。同时在综合研究微观特性的基础上构建了复合吸附剂的分子结构单体模型,基于密度泛函理论,并利用分波态密度函数,对Hg0在复合吸附剂表面的吸附过程进行理论计算,进一步揭示深层次的脱汞机理以及关键作用机制。结果表明:Cu-BTC材料的脱汞性能优于改性生物焦,而基于2种材料进行复合所获得的Cu-BTC基改性生物焦样品脱汞性能获得了显著提升,最优负载比例为50%,对应汞脱除性能高达239.18μg/g;复合吸附剂的分子模型主要以芳香结构为主,并含有2个吡啶氮并苯,1个蒽并苯以及1个呋喃,分子式为C75H34O_(2)8N3Fe2Cu13,分子量Mr=2361.5;多元金属团簇、氧空位和碳骨架的协同作用利于活性中心的暴露,同时改性生物焦作为底物载体,可在负载于交联的MOFs骨架中提供更多的金属中心和碳骨架,进而在提升反应体系电子受体容量和传质能力的基础上,防止金属氧化物粒子在热处理过程中自聚集形成高度分散的金属中心,从而协同促进对Hg0的脱除。Composite adsorbents were prepared using a combination of modified biochar and MOFs through an in-situ growth method.The modified biochar was doped with Fe/Cu polymetallic and Cu-BTC,both containing unsaturated met-al centers and oxygen-containing functional groups.The study focused on identifying the Hg^(0) removal characteristics,in-vestigating the coupling and synergistic mechanisms between Cu-BTC and modified biochar,and examining the various types of active centers present.A molecular structure model of the composite adsorbent was developed based on micro-scopic properties,and theoretical calculations of the Hg^(0) adsorption process were conducted using density functional the-ory,and fractional-wave state density function to uncover the underlying mechanisms of mercury removal and key actions.The study revealed that the Cu-BTC material exhibited better mercury removal performance compared to modified biochar.Furthermore,the mercury removal efficiency of Cu-BTC-based modified biochar samples,resulting from a com-bination of the two materials,was significantly enhanced.The optimal loading ratio was found to be 50%,leading to a re-markable mercury removal performance of 239.18μg/g.The molecular model of the composite adsorbent primarily con-sisted of aromatic structures,including two pyridinium azobenzenes,one anthracene benzene,and one anthracene benzene.The synergistic effect of polymetallic clusters,oxygen vacancies,and carbon skeleton facilitated the exposure of active centers.Moreover,the modified biochar acted as a substrate carrier,providing additional metal centers and carbon skelet-ons within the crosslinked MOFs structure,thereby enhancing electron acceptor and transfer capacities of the reaction sys-tem.By improving the electron acceptor capacity and mass transfer ability of the system,the formation of highly dis-persed metal centers was promoted during heat treatment,preventing self-aggregation of metal oxide particles and syner-gistically enhancing Hg^(0) removal.

关 键 词：Cu-BTC 改性生物焦 复合材料 分子结构 汞脱除机理 密度泛函 

分 类 号：X51[环境科学与工程—环境工程]