自由基辅助粉煤灰合成沸石分子筛的研究进展  

Research Progress on Free Radical Assisted Synthesis of Zeolite from Fly Ash

作　　者：梁鼎成 张蕊聪 解强[1] 谢珠璨 刘缘 LIANG Dingcheng;ZHANG Ruicong;XIE Qiang;XIE Zhucan;LIU Yuan(School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《硅酸盐学报》2024年第1期347-358,共12页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(22008255);国家重点研发项目(2022YFC3701901,2022YFD2200904);中央高校基本科研业务费(2022XJHH06)。

摘　　要：沸石分子筛(简称沸石)在吸附、分离和催化等领域具有广阔应用前景,但沸石合成速率慢、工业化生产效率低;同时高品质沸石主要由化学原料合成,制备成本高,因此,利用自由基提高合成速率,以粉煤灰为硅铝源降低合成成本,对沸石的工业化生产和大宗固废的消纳具有重要的现实意义。本文对自由基促进沸石合成的作用机理进行调研,同时探究自由基促进粉煤灰硅铝活化的可能机制,挖掘自由基在沸石合成体系中的产生及存在,并针对粉煤灰来源广、成分杂问题,系统梳理了各类预处理方法,在此基础上,提出了利用自由基有望解决粉煤灰中硅铝活化难的问题,这将为粉煤灰大规模、高值化利用提供可能途径。Zeolites have broad application prospects in adsorption,separation,catalysis,etc..Improving their synthesis efficiency and reducing their production cost become a challenge.The synthesis rate of zeolite is low and the production period is long due to the prolonged nucleation and growth of crystals during the crystallization process.Furthermore,commercial high-quality zeolites are mainly synthesized with chemicals as raw materials,resulting in high costs.Therefore,it is significant to develop efficient and low-cost zeolite synthesis technologies.Some previous studies indicate that the use of free radicals could achieve a rapid synthesis of zeolites.Fly ash contains a large amount of silicon and aluminum elements.As a result,the synthesis of zeolite from fly ash reduces costs,and provides a feasible way for its high-value utilization.However,there is little work on the synthesis of zeolite from fly ash assisted by free radicals.It is thus necessary to explore the mechanism of free radical assisted synthesis of zeolite from fly ash,as well as the generation,types and properties of free radicals.Meanwhile,it is revealed that free radicals solve the problem of difficult activation of inert silicon and aluminum in fly ash.The theoretical basis is provided for the development of efficient and low-cost synthesis technology for the preparation of zeolite from fly ash assisted by free radicals,and a reference is provided for other coal based solid waste.The existence of·OH in zeolite synthesis systems was firstly discovered in 2016.·OH was introduced into the synthesis system of NaA,Y,and ZSM-5 zeolites,thus greatly accelerating their crystallization process.This is a high-efficient method for zeolite synthesis besides a microwave method.Meanwhile,electron paramagnetic resonance (EPR) was used to determine hydroxyl radicals,and density functional theory (DFT) was used for the theoretical calculations to investigate the mechanism of hydroxyl radicals accelerating the synthesis rate of zeolite.The catalytic activity by·OH

关 键 词：沸石分子筛 自由基 粉煤灰 催化机理 硅铝活化 

分 类 号：TQ536.4[化学工程—煤化学工程]