等级介孔分子筛分级互补吸附室内VOCs的机理研究

Anchored to the newest advance in molecular sieves, this study proposes removing indoor VOCs by the hierarchically complementary adsorption through the micro-meso porous systems in hierarchically mesoporous materials. Using structural characterization, zero-length column experiment, and the theory of nonparametric statistics, this work will systematically study the mass transfer of VOCs and key rate-controlling mechanisms of intra-crystalline diffusion in hierarchically mesoporous molecular sieves, with an emphasis on the influence of hierarchical structures and surface characteristics of molecular sieves on the rate of VOCs diffusion. The study will illustrate the synergistic effects of micro-meso pore structure on the three processes and the three effects associated with adsorption by fix-bed adsorption experiment and modelling study based on the theory of adsorption kinetics, in order to demonstrate the dynamic performance of fix-bed purification systems based on hierarchically porous molecular sieves. The achievements of this study can promote the interdisciplinary coalescence of nanomaterial science and indoor VOCs adsorption technology, as well as provide a scientific foundation for developing indoor adsorption systems using hierarchically mesoporous materials as adsorbent.

基于纳米分子筛的最新进展，提出利用等级介孔分子筛分级互补吸附室内VOCs的全新思路。综合运用微观结构表征、零长柱实验和非参数统计理论，深入剖析室内VOCs气体在等级介孔分子筛中的传质过程，以及晶内扩散的关键控速机理，重点考察等级孔级配结构和固体表面特性对晶内扩散速率的影响；开展固定床吸附实验，构建固定床吸附动力学模型，阐明微-介孔等级孔体系对促进吸附净化的三个过程和三种效应之间相互渗透、协同互补的机理，论证基于等级孔分子筛的固定床净化系统的动态吸附性能；成果将推动室内VOCs吸附技术与纳米材料科学的融合，为发展基于等级介孔分子筛的室内吸附系统提供理论依据。

吸附脱除室内挥发性有机物（VOCs）是目前最常用的空气净化方法。本课题结合纳米多孔材料领域的最新发展，提出采用有序介孔材料分级互补吸附室内VOCs的思路。为此，本课题研究了在室温条件下若干有序介孔材料分级互补吸附气相VOCs的传质控速机理与级配协同效应。采用扫描电镜、透射电镜、吸附法等手段，表征了XF系列介孔材料（XFSBA-15、XFMCM-41和XFKIT-6）的微观孔隙结构。开展了XFSBA-15/XFMCM-41/XFKIT-6对苯系物在室温度变化范围内的吸附等温与平衡吸附量的实验研究，构建了相应的Langmuir吸附方程。基于零长柱（ZLC）理论，运用非参数统计理论的思想，发展了一套鲁棒的、非拟合的晶内扩散系数反演与误差估计方法。改进了传统的ZLC全时间参数反演方法，构建了分步全时间参数反演算法。综合传质理论、吸附平衡和吸附动力学理论，构建等级分子筛固定床吸附有机气体的数理模型。开展了室温条件下XF系列等级介孔分子筛吸附常见苯系物的固定床吸附实验，系统地测定了动态吸附量和穿透时间。阐明了介孔材料的微-介孔网络体系与结构特征对相际传质、粒内扩散和吸附过程的影响机理。研究成果为发展基于等级介孔材料的室内吸附系统和装置提供了理论模型、参数反演算法等理论支持，将有助于推动等级介孔材料在吸附室内气相污染物方面的应用。