多功能负载型催化剂活性中心的组装和功能优化

A multi-functional solid catalyst is the ideal alternate of the mixed "metal + NaOH" and "metal + acid" for the selective oxidation of alcohols (especially those polyols). And the preparation and characterization of these solid catalysts with several kinds of active centers (such as acid/base, metal/alloy nanoparticles, hydrogen spillover etc.) is a hard work in catalysis, materials and surface science. Designing efficient solid-state catalysts would be easier if we knew which parts of them do what (Nature 439, 548 (2 February 2006)), but the main challenge is how to assembly different kinds of active centers at the atomic scale onto one solid support, and how to map the difference of these active centers before and after cooperated with others..The main objective of this project is to design, synthesize and characterize several types of multifunctional solid catalysts with the active centers such as dehydration (hydrolysis) and hydrogenation (dehydrogenation) via self-assembly method. And the performance of these catalysts will be investigated and compared in detail in the selective oxidation and hydrogenolysis of glycerol. The properties of these active centers such as acid/base strength, the metal/alloy particle size/crystal structure and their optimized composition will be characterized and discussed with their catalytic performance. The role and reaction mechanism of these active centers in the selective oxidation and hydrogenolysis of glycerol will be investigated via in-situ Raman, FTIR and NMR. .The main contents of this project includes (1) preparation and characterization a series of solid acids (such as Zn-Al-O), solid bases (such as Mg-Al-O) and coexisted acid-base (such as Zn-Mg-Al-O) via controlled calcination of multi-layered or single-layered double hydroxide; (2) preparation and characterization a series of mesoporous structure Na(H)-ZSM5 and Na(H)-Beta with controlled amount of active cites; (3) modification of active carbon, multiwall carbon nanotubes and graphene with different strengthened and controlled amount of acid-base active centers; (4) synthesis of metal (or alloy) particles with controlled size and crystal structure on the surface of above solid acid/base; (5) investigation of the catalytic performance of these solid acid/base, metal (alloy) particles and multifunctional catalysts in the selective oxidation and hydrogenolysis of glycerol; and (6) investigation of the adsorption, activation and reaction mechanism of glycerol over these mono-functional catalysts, multi-functional catalysts via in-situ Raman, FTIR and NMR.

用于复杂反应、具有多功能、多类活性中心的固体催化剂的制备和功能优化在化学、材料等领域都具有重要的意义和应用前景，是该领域的研究热点和前沿。本项目拟通过自组装技术制备系列具有加氢(脱氢)、脱水(水合)等多类活性中心共存的负载型催化剂；揭示组装过程中不同活性中心间相互作用的本质和协同规律，在原子水平上实现对多功能固体催化剂自组装过程的调控，并根据目标反应的特点设计制备系列具有复合功能的催化剂；考察这些催化剂在甘油转化中的活性、作用规律和不同活性中心间的协同机理。项目以催化剂表面多类活性中心间的协同规律研究为指导、以原位及动态表征技术为支撑，通过在催化剂表面组装可以协同催化目标反应的多类活性中心，建立多层次、多组份的可控自组装新方法，发展功能导向的自组装新体系和新技术；研究多类活性中心在催化剂表面上可控组装的过程及调控规律、以及这些具有多类活性中心的催化剂在新能源利用和复杂化学反应中的作用规律。

可用于复杂反应、具有多功能、多类活性中心的固体催化剂的组装和功能优化在化学、材料等领域都具有重要的意义和应用前景，是该领域的研究热点和前沿。本项目在国家自然科学基金的资助下，先后探索了零维材料（磁性球形氧化铁颗粒）、一维材料（碳纳米管、碳纤维、金属纳米棒）、二维材料（石墨烯、水滑石）和三维材料（碳纳米管柱撑的石墨烯、水滑石）的表面及体相中具有加氢、脱水等多类催化活性中心的组装方法，制备出结构新颖、活性突出的催化剂，探索了这些催化剂在硝基化合物、烃类、不饱和醛以及甘油的氧化及氢解等反应中的活性规律。初步实现了固体表面不同种类催化活性中心的可控组装、揭示了这些活性中心在系列目标反应中的协同作用机理；建立并完善了组装后负载型催化剂的表征方法、活性检测方法和反应机理的原位表征手段。在本项目的资助下，先后发表SCI论文23篇（其中一区论文7篇）、国际会议论文10篇、申请国家发明专利14件（其中2件已授权）、培养硕博士研究生8人、参加国际国内学术会议8人次。技术创新：①在石墨烯复合催化材料、纳米碳管复合催化材料和水滑石基催化材料的绿色、快速合成等方面取得重要的突破；②在甘油等多元醇的活化和转化反应机理的研究技术中取得重要进展。新发现：①水滑石表面高分散铜基催化剂的制备、表征及其在甘油转化反应中的活性规律；②石墨烯表面高分散活性金属的组装及其在加氢、偶联、氨氧化反应中的活性规律等成果引起国内外研究同行的重点关注和积极评价。