疏水性核壳催化剂对褐煤热解挥发分重整反应的调控机制研究

褐煤热解挥发分原位重整制备轻质芳烃是一种极具潜力的焦油轻质化途径。然而，热解水的存在不但减弱了褐煤热解挥发分重整效率，并且破坏了催化剂原有结构。如何抑制热解水对煤热解挥发分重整反应的影响是急需解决的关键问题之一。本项目通过在分子筛基催化剂表面生长silicalite-1（S-1）分子筛疏水膜，精准构筑了一种疏水性核壳催化剂，以避免水与催化剂活性位直接接触，提高催化效率和稳定催化剂结构。考察水与焦油模型化合物挥发分共催化产物组分分布，分析催化过程中水对分子筛酸性和结构的影响，揭示热解水对煤热解挥发分重整过程的影响机制。研究疏水性核壳催化剂对褐煤热解挥发分重整反应，测定产物组分分布，建立疏水性能与煤热解挥发分重整产物分布的构效关系，阐明疏水性核壳催化剂对褐煤热解挥发分重整的调控机制。本项目旨在深入揭示褐煤热解挥发分重整机理，为褐煤热解定向制备轻质芳烃高效催化剂的开发和工艺优化提供理论依据。

In situ catalytic upgrading of lignite pyrolysis volatiles to produce light aromatics provides a potential way for converting of coal-tar to light aromatics. However, the presence of pyrolysis water not only weakens the efficiency of reforming lignite pyrolysis volatiles, but also destroys the original structure of the catalyst. It is an urgent technology to be developed to restrain the influence of pyrolytic water on lignite pyrolysis volatiles reforming process. This present project finely constructed a hydrophobic core-shell zeolite catalyst by extending and growing silicalite-1 membrane on the surface of zeolite. The hydrophobic membrane will keep the pyrolysis water from contracting the active sites. By this way, the improved catalytic efficiency and catalytic stability will be achieved. The mechanism of pyrolysis water on upgrading lignite pyrolysis volatiles will be revealed by studying the products distribution of vapors co-catalyzed with water and analyzing the influence of acid property and structure of catalyst. By studying the process of upgrading lignite pyrolysis volatiles and detecting the products distribution (selectivity and product yields) over hydrophobic core-shell catalyst, the structure-activity relationship of the hydrophobic performance between products distribution will be illustrated, and the regulation mechanism during upgrading of lignite pyrolysis volatiles over hydrophobic core-shell catalyst will be revealed. The present research aims to have an in-depth understanding of the catalytic reforming mechanism of lignite pyrolysis volatiles, and offer theoretical clues for designing more efficient catalyst and optimization the process to realize lignite pyrolysis vapors oriented converting to high-valued chemicals.