甲醇制氢铜铝尖晶石催化剂的制备与结构化学基础

Based on the principle of sustained release of active copper during catalytic reaction, the Cu-Al spinel catalyst with an excellent catalytic performance has been developed. Further investigation finds that the releasing process is greatly affected by the microstructure of Cu-Al spinel, however the catalytic nature, and the required microstructure as well as the controlled synthesis remain to be resolved. In this study, different preparation methods and parameter controlled syntheses will be performed with the theoretical guidance of density functional theory calculation results, aiming at obtaining catalysts with different microstructure. The distribution and transformation of Cu and Al between tetrahedron and octahedron sites, and the transformation mechanism will be investigated. The characteristics of copper release, migration and sintering, and the evolution nature of the remnant structure will be researched by combing the results of characterizations at simulated reaction conditions and theoretical calculations, and then the theoretical models will be established. Using the methanol transformation to hydrogen as the probe reaction, the catalytic performance and the effects of process parameters will be evaluated. Based on the above data, the correlation among the evaluation, characterization and theoretical calculation will be constructed, and then the detailed mechanistic aspects of the impact of microstructure of Cu-Al spinel on the catalytic performance can be obtained. In short, the results of this research will demonstrate the relationships among catalyst preparation, microstructure and catalytic performance, providing theoretical support and fundamental data for further study of sustained release catalysis of the copper based spinel catalyst.

依据反应过程中逐步缓释活性Cu的催化原理，具有尖晶石结构的铜铝催化剂表现出优异的催化性能，进一步研究显示催化剂的微观结构对缓释过程有较大影响，然而对其调控合成及作用机制尚不清楚。本项目拟采用不同制备方法和条件控制的合成研究，结合以密度泛函理论(DFT)计算尖晶石结构中铜、铝分布及其所占四面体和八面体位置相互转化的理论指导，获得具有不同微观结构的尖晶石催化剂，探讨尖晶石结构的可能形成和转化机制。通过模拟反应条件的表征和理论计算，详细研究催化剂中Cu的缓释、迁移烧结特征，以及留存结构的演变规律，建立相应的理论结构模型。以甲醇制氢为探针反应，考察反应条件的影响规律，建立催化性能与理论计算和表征间的关联性，揭示铜铝尖晶石催化剂微观结构对其催化性能影响的详细作用机制。通过本项目的研究，阐明催化剂制备-微观结构-反应性能三者之间的关系，以期为尖晶石铜基催化剂缓释催化概念的深入研究提供重要理论支持和基础。

采用水热法、液固法和固相法等不同制备方法，通过合成参数条件控制的研究，获得了具有Cu-Al氧化物及三元M-Cu-Al(M=Mg, Ni)尖晶石固溶体催化材料。结合表征数据，并以密度泛函理论(DFT)计算尖晶石结构中铜、铝分布及其所占四面体和八面体位置相互转化的理论指导，获得具有不同微观结构的尖晶石催化剂，提出了尖晶石结构的可能形成和转化机制，为尖晶石合成化学提供了基础数据。通过模拟反应条件的表征和理论计算，详细研究催化剂中Cu的缓释、迁移烧结特征，以及留存结构的演变规律，为建立相应的理论结构模型提供参考。以甲醇制氢为探针反应，考察反应条件的影响规律，建立催化性能与结构和缓释性能的关联性，揭示铜铝尖晶石催化剂微观结构对其催化性能影响的详细作用机制。提出“缓释催化”新概念，并基于此获得性能优异的甲醇制氢缓释催化体系。本项目的研究，为尖晶石铜基缓释催化剂的进一步研究和缓释概念的拓展应用提供了重要理论支持和基础数据。