Construction and adsorption performance of coal fly ash-based hierarchical porous zeolite A
-
摘要: 在“双碳”战略和循环经济协同推进的背景下,燃煤电厂粉煤灰的高值化资源利用与多尺度污染物治理已成为重要研究课题。然而,以粉煤灰为原料直接构筑兼具微孔骨架与介孔传质通道的多级孔A型沸石,因原料杂质背景复杂、晶相可控生长与孔结构协同调控难度大而面临显著挑战。针对传统微孔A型沸石存在孔道狭窄、传质受限、难以高效去除较大尺寸污染物的瓶颈,研究以酸处理粉煤灰为硅铝源,采用软模板剂辅助的碱熔-水热法,成功构筑了具备三维互联介孔网络的多级孔A型沸石。系统考察了模板剂种类及添加量对产物晶相、形貌及孔结构演化的影响机制。结果表明:当以二甲基十八烷基[3-(三甲氧基硅基)丙基]氯化铵(TPOAC)为模板剂,其质量分数为3%时,沸石呈现由纳米晶粒自组装形成的阶梯状粗糙立方体形貌,其比表面积和总孔容分别达到57.0 m2/g 和0.1351 cm3/g,较传统微孔沸石分别提升了约3,4倍。进一步以水相氨氮和气相丙酮作为探针污染物,揭示了多级孔结构对不同吸附机理污染物的差异化响应规律:对于依赖离子交换机制的氨氮,多级孔结构主要起改善传质的作用,其吸附容量与微孔A型沸石相近;而对于受限于分子筛分效应的丙酮大分子,多级孔A型沸石依托发达的介孔容积有效克服了空间扩散位阻,诱导了高效的毛细管凝聚,使其吸附量由微孔沸石的12 mg/g显著跃升至59 mg/g,实现了近4倍的增长。研究阐明了孔道结构演化与差异化吸附行为间的构效关系,为粉煤灰的规模化消纳及复杂污染物治理材料的定向设计提供了可靠的理论与技术支撑。Abstract: Driven by the synergistic advancement of the Dual Carbon Strategy and the circular economy, the high-value resource utilization of coal fly ash from coal-fired power plants and the multiscale remediation of environmental pollutants have emerged as critical research topics. However, the direct construction of hierarchical porous zeolite A,which integrates a microporous framework with mesoporous mass-transfer channels,from coal fly ash remains a significant challenge. This is largely due to the complex impurity background of the raw material and the difficulty in synergistically controlling crystalline phase growth and pore architecture. To address the inherent bottlenecks of conventional microporous zeolite A, such as narrow pore channels, severe mass-transfer limitations, and inefficiencies in removing larger pollutant molecules, this study successfully synthesized a hierarchical porous zeolite A featuring a three-dimensionally interconnected mesoporous network. This was achieved via a soft-template-assisted alkali fusion-hydrothermal method, utilizing acid-treated coal fly ash as the silica-alumina source. The underlying mechanisms governing the effects of template type and dosage on the crystalline phase, morphological evolution, and pore structure of the products were systematically investigated. The results demonstrated that using 3 % dimethyloctadecyl[3-(trimethoxysilyl)propyl] ammonium chloride (TPOAC) as the template,the prepared zeolite yielded a step-like, rough cubic morphology formed by the self-assembly of nanocrystals. Its specific surface area and total pore volume reached 57.0 m2/g and 0.1351 cm3/g, respectively, representing approximately three- and four-fold increases compared to conventional microporous zeolite A. Furthermore, aqueous ammonia nitrogen, and gaseous acetone were employed as probe pollutants to elucidate the differential response mechanisms of the hierarchical pore structure toward contaminants with distinct adsorption mechanisms. For ammonia nitrogen, which primarily relies on an ion-exchange mechanism, the hierarchical pores mainly served to improve mass transfer, yielding an adsorption capacity comparable to that of microporous zeolite A. In contrast, for larger acetone molecules restricted by the molecular sieving effect, the hierarchical porous zeolite A leveraged its highly developed mesoporous volume to effectively overcome steric diffusion hindrance. This induced highly efficient capillary condensation, resulting in a dramatic surge in acetone adsorption capacity from 12 mg/g (for conventional microporous zeolite) to 59 mg/g, a nearly four-fold increase. This study elucidates the structure-activity relationship between pore architecture evolution and differential adsorption behaviors, providing robust theoretical and technical support for the large-scale utilization of coal fly ash and the targeted design of advanced remediation materials for complex environmental pollutants.
-
Key words:
- coal fly ash /
- hierarchical porous zeolite A /
- template agent /
- differential adsorption
-
[1] ZHU W J,GUO J C,YAN Y,et al. Current situation of comprehensive utilisation of fly ash in the background of dual carbon[J]. Guangzhou Chemical Industry,2025,53(21):18-21. 朱文娟,郭敬超,燕音,等.“双碳”背景下粉煤灰综合利用现状[J]. 广州化工,2025,53(21):18-21. [2] SUN H J,ZENG L,PENG T J. Research status and progress of high-value utilization of coal fly ash[J]. Materials Reports,2021,35(3):3010-3015. 孙红娟,曾丽,彭同江. 粉煤灰高值化利用研究现状与进展[J]. 材料导报,2021,35(3):3010-3015. [3] SADIQ S,CHATHA S A S,ALI S,et al. Microwave assisted synthesis of fly ash based zeolites for degradation of reactive blue 19 dye from wastewater[J]. Scientific Reports,2025,15:16028. [4] CHEN D,ZHANG T,YIN X,et al. Size-inverse molecular sieving xenon/krypton separation through cation-tuned gating effect within Linde Type A zeolites[J]. Nature Communications,2025,16:9894. [5] MAMAGHANI F A A,SALEM A,SALEM S. Management of solid waste after used motor oil recovery via production of zeolite A[J]. Environmental Science and Pollution Research,2022,29:55877-55889. [6] ZHAO S Y,XIAO Y C,MA Q Q,et al. Study on adsorption of Cu(Ⅱ)on 4A zeolite synthesized by aluminum extraction residue by fly ash[J]. Inorganic Chemicals Industry,2024,56(10):127-134. 赵世永,肖雨辰,马清清,等. 粉煤灰提铝残渣制备4A分子筛及Cu(Ⅱ)吸附研究[J]. 无机盐工业,2024,56(10):127-134. [7] XU Q B,NIU X L,CHEN T T,et al. Preparation of 4A molecular sieve from coal gasification slag and its adsorption performance[J]. Bulletin of the Chinese Ceramic Society,2023,42(6):2251-2261. 徐啟斌,牛香力,陈婷婷,等. 煤气化渣合成4A分子筛及其吸附性能研究[J]. 硅酸盐通报,2023,42(6):2251-2261. [8] 罗军. 改性吸附材料去除水中氨氮的研究进展[J/OL]. 化工新型材料,1-7[ 2026-07-27]. https://doi.org/10.19817/j.cnki.issn1006-3536.2026.11.027.LUO J. Research progress on modified adsorption materials for ammonium removal from water[J]. New Chemical Materials,2026:1-7[ 2026-07-27]. https://doi.org/10.19817/j.cnki.issn1006-3536.2026.11.027. [9] TANG Y Z. Design and preparation of new functional porous materials for the monitoring and adsorption removal of environmental pollutants[D]. Beijing:Beijing University of Chemical Technology,2020. 唐渊哲. 新型功能多孔材料设计制备及其环境污染物监测和吸附脱除性能研究[D]. 北京:北京化工大学,2020. [10] JIANG D L. Research on the preparation and modification of synthetic zeolite from fly ash and its nitrogen and phosphorus removal[D]. Nanchang:Nanchang University,2026. 蒋得璐. 粉煤灰基沸石的制备与改性及其脱氮除磷研究[D]. 南昌:南昌大学,2026. [11] YUAN J Y,ZHU D Y,HUANG Z H,et al. Acetone adsorption properties,thermal stability and spontaneous combustion mechanisms of activated carbons[J]. Coal Conversion,2026,49(3):89-101. 袁金玉,朱东瑶,黄子豪,等. 活性炭的丙酮吸附性能与热稳定性及自燃机制研究[J]. 煤炭转化,2026,49(3):89-101. [12] BELACHEW N,HINSENE H. Preparation of zeolite 4A for adsorptive removal of methylene blue:optimization,kinetics,isotherm,and mechanism study[J]. Silicon,2021,14(4):1629-1641. [13] TANG W,HAN J,ZHANG S,et al. Synthesis of 4A zeolite containing la from kaolinite and its effect on the flammability of polypropylene[J]. Polymer Composites,2017,39(10):3461-3471. [14] DAI R J,ZHAO Y Q,DOU J X,et al. Synthesis of zeolites A and H from coal fly ash and their adsorption mechanism for SO2,CO2 and NO[J]. Environmental Engineering,2026,44(4):219-228. 代芮嘉,赵永奇,窦金孝,等. 粉煤灰制备A、H型分子筛及其吸附SO2、CO2和NO的机制[J]. 环境工程,2026,44(4):219-228. [15] SHI Y,ZHANG X,LIU G. Activated carbons derived from hydrothermally carbonized sucrose:remarkable adsorbents for adsorptive desulfurization[J]. ACS Sustainable Chemistry& Engineering,2015,3(9):2237-2246. [16] LIU Z J. Construction of fully inorganic system for hierarchical ZSM-5 zeolite[D]. Beijing:Beijing University of Chemical Technology,2025. 刘兆隽. 多级孔ZSM-5分子筛的无机合成体系构建[D]. 北京:北京化工大学,2025. -
点击查看大图
计量
- 文章访问数: 2
- HTML全文浏览量: 1
- PDF下载量: 0
- 被引次数: 0
登录
注册
E-alert
登录
注册
E-alert
下载: