锆基（复合）金属氧化物纳米催化材料的设计、制备及性能研究

发布时间：2018-04-16 18:07

本文选题：ZrO_2 + 铜基催化剂　；参考：《北京化工大学》2017年硕士论文

【摘要】：随着能源危机和生态环境问题的加剧,生物质能源的利用与转化备受关注。生物质来源丰富、用途广泛,可用于制备一些生物基平台分子、精细化学品、液态燃料及燃料添加剂等。生物质资源因为组成和结构的复杂性,对所用催化材料的设计和制备提出了新的要求和挑战。目前用于生物质转化与利用的催化剂大都存在稳定性差,可循环性利用性和选择性低、反应条件苛刻等缺点。因此通过深入探究催化剂的构效关系,对催化剂的结构和表面性质进行控制合成,从而实现催化性能的强化和提升,对于生物质资源的转化和利用具有重要的理论和现实意义。ZrO2因其较高的比表面积、合适的孔结构、丰富的表面酸碱活性中心和氧空位,被广泛用作催化剂或者负载型催化剂的载体材料。本文针对传统方法在制备锆基纳米催化材料方面存在的制备过程复杂、原料易水解或有毒、缺乏对材料织构性能和表/界面性质的有效控制等问题,基于成核/晶化隔离法在制备超细纳米材料方面的优势,创制了新的制备方法用于制备负载型金属催化剂及酸碱催化剂,系统研究制备方法、条件及参数等对催化剂结构和性能的影响规律,并将所得催化剂应用于生物质的加氢酯化、羟醛缩合反应中,深入系统地研究催化剂的结构和性能间的内在关系,为新型高效催化材料的制备及应用提供了实验基础和一定的理论依据。(一)创制了成核/晶化隔离法辅助的还原-氧化法,并将其应用于高分散负载型Cu/Zr02催化剂的制备,实现了 Cu活性组分的引入及载体合成的同步进行。通过简单调变NaBH4浓度便可实现对催化剂织构性能、表面酸/碱性、表面Cu+/(Cu0 + Cu+)比例等的控制合成。独特的制备路径及前体中Cu、Zr组分的高度均匀分散强化了活性组分和载体间的相互作用,形成了大量表面Cu+活性中心,Cu+的存在利于GVL分子中的羰基吸附和极化,高分散的Cu0利于氢气的解离及中间产物的加氢反应,二者间的紧密合作使得催化剂在GVL催化转化生成戊酸戊酯的过程中展现了出优异的催化性能。该方法为新型高效负载型催化材料的可控合成提供了一种新的思路和方法。(二)开发了成核/晶化隔离法辅助的动态水热晶化法,并将其应用于酸碱双功能催化剂的制备。通过控制制备条件及参数、掺杂元素的种类及掺杂量,实现对催化剂表面酸碱活性中心数量和强度的控制合成。所得Al/Zr-1催化剂在糠醛和丙酮的羟醛缩合反应中展现了优异的催化性能(92.0%的糠醛转化率和98.7%的亚糠基丙酮选择性)。催化剂表面碱性位和酸性位之间的协同作用是催化剂在羟醛缩合反应中表现优异的主要原因。
[Abstract]:With the energy crisis and environmental problems intensified, biomass energy utilization and transformation of concern. The biomass rich source, wide range of uses, can be used in the preparation of some bio platform molecules, fine chemicals, liquid fuels and fuel additives. Biomass resources because of the complexity of its composition and structure, new demands and challenges to the the design and preparation of catalytic materials preparation is proposed. Currently used for biomass conversion and utilization of catalyst have poor stability, recycling utilization and low selectivity, harsh reaction conditions and other shortcomings. Therefore by studying the structure-activity relationship of catalyst, structure and surface properties of the catalysts were synthesized, strengthen and improve in order to achieve catalysis the performance of transformation and utilization for biomass resources has important theoretical and practical significance of.ZrO2 because of its high specific surface area, suitable hole The structure, surface acidity and activity center and the oxygen vacancy rich, widely used as catalyst or catalyst carrier material. The preparation process of the traditional method of preparing zirconium based nano catalytic materials in the business aspects of the complex, the raw material is easy hydrolysis or toxic, lack of material texture properties and surface / interface properties of effective control such problems, a new method for the preparation of ultrafine nano materials based on the advantages of the new preparation method for the preparation of supported metal catalysts and acid-base catalyst development, system of preparation method, influence of conditions and parameters on the structure and properties of catalyst, and hydrogenation esterification catalyst used for biomass, aldol reaction, relationship between structure and properties of catalyst is systematically studied between the new and efficient catalytic materials preparation and application provides experiment The foundation and theoretical basis. (a) to create a new method assisted reduction oxidation method, and its application in the preparation of highly dispersed Cu/Zr02 catalyst, the Cu adding active component and carrier synthesis simultaneously. By simply varying NaBH4 concentration can be achieved the catalyst textural properties, surface acid / alkaline surface Cu+/ (Cu0 + Cu+) ratio control synthesis. The path and precursor in the preparation of Cu unique, Zr components of highly dispersed and strengthen the interaction between the active component and the support, the formation of a large number of surface Cu+ activity center of the carbonyl group the adsorption and polarization for GVL molecules in Cu+, hydrogenation of highly dispersed Cu0 for hydrogen dissociation and intermediate product, the two close cooperation between the catalyst and conversion process of amyl valerate in GVL catalysis showed excellent catalytic to the. Provides a new idea and method for controllable synthesis of new high load type catalytic material. (two) developed into a dynamic hydrothermal crystallization crystallization assisted nuclear / isolation method, and its application in dual function catalyst preparation. By controlling the pH conditions and parameters of preparation, type and doping the amount of doping elements, to achieve control of the synthesis of the number and intensity of surface acidity and the active centers of the catalyst. The Al/Zr-1 catalyst showed excellent catalytic performance in the aldol reaction of furfural and acetone in (furfurylidene acetone 92% furfural conversion and 98.7% selectivity). The surface acidic and alkaline catalyst the synergy between the catalyst is mainly due to outstanding performance in the aldol reaction.

【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TB383.1

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