ZSM-5@ZrO2复合催化剂核壳结构构造及甲醇和硫化氢吸附转化行为

针对硫化氢-甲醇法合成甲硫醇工艺存在产品收率低、催化剂寿命短等问题，项目提出构造基于微-介孔体系的ZSM-5@ZrO2催化剂核壳结构，形成L-B酸活性中心和核（弱酸）-壳（碱性为主）特殊反应路径的协同催化环境，以解决同时提高甲醇转化率和甲硫醇选择性要求不同酸碱中心和不同反应温度的瓶颈问题。系统研究核相表面电荷性质调变、晶种浸渍播种、壳相晶粒二次生长等制备工艺条件对催化剂核壳结构、物化性质及吸附转化特性的影响，使催化剂在较低反应温度下能提供有效增强甲醇转化率、抑制甲硫醚、碳氢及碳氧等副产物生成和缓解失活速率的协同环境。掌握催化剂制备条件与结构性质、结构性质与甲醇和硫化氢分子吸附转化行为的影响规律，建立催化剂构效关系，揭示甲醇脱水与甲硫醇合成竞争反应机制和催化剂失活行为，最终形成低能耗、高效经济性甲硫醇合成技术。研究成果将为我国同类多相酸碱催化技术提供借鉴，具有重要科学意义和应用前景。

Since the disadvantages of low methanethiol yield and short catalyst lifetime in the thiolation of methanol with H2S, the design and fabrication of a ZSM-5@ZrO2 composite with a core-shell and hierarchical structure is proposed as a manner to solve the problems that simultaneous enhancements for methanol conversion and methanethiol selectivity require completely different activity sites of catalyst and reaction temperature, by the formation of synergistic catalytic effect of L-B acid sites combined with unique reaction route of core(weak acid sites)-shell(mostly base sites). Impacts of procedures including tune processing of surface charge property of core phases, impregnation operation of ZrO2 seeds and secondary growth of shell crystals on core-shell structures, physicochemical characteristics and adsorption conversion properties are taken into account in this project, aiming for that an obtained novel composite catalyst with a core-shell structure exhibits the synergistic catalytic effect, considerably enhancing the methanol conversion, restraining the formation of dimethyl sulfide, hydrocarbon, carbon oxides and etc. and alleviating the deactivation rate of the catalyst. It is expected that a highly economical methanethiol synthesis technology with low energy consumption could be developed by exploring the interactions of preparation conditions and structure properties, structure properties and adsorption conversion behaviors of methanol and hydrogen sulfide, establishing the structure-activity relationships, and revealing the competition reaction mechanisms between methanol dehydration and methanethiol synthesis and deactivation behavior of the catalyst. Finally, our research achievements would provide the reference for other similar heterogeneous catalysis, exhibiting important scientific significance and application prospects.