限域型铁基纳米催化剂的制备及其原位穆斯堡尔谱研究

In recent years, confined nanocatalysis has been a hot topic in the field of catalysis， and has significance for combination of nanoscience/nanotechnology and catalysis research. However, as far as I know, there is no well accepted explanation for the origin of confined effect and its action mechanism on catalysis, which due to the limitations from synthesis conditions and research techniques. Therefore, this application will study the architecture and catalytic performance of FeOx@C and FeOx@SiO2 confined materials, which is intended to elucidate the relationship between confined effect and structure, as well as the action mechanism on catalysis. First, the confined catalysts with controllable structural parameters will be prepared. Then the physical and chemical properties of the catalysts such as phase, valent state and redox behavior, will be systematically studied through in-situ Mössbauer spectroscopy and some other techniques. Finally, the NH3 decomposition and Fischer-Tropsch synthesis will be used to test the catalytic performances of the confined catalysts. By study the relevance of the architecture and catalytic performance, we can have a deep insight into confined nanocatalysis. This application will provide reference for the development of preparations of nanomaterials and the design of active catalysts.

纳米限域催化是近年来催化领域研究的热点，对于沟通纳米科学技术与催化相结合具有重要的意义。但是，受限域体系的合成条件以及研究手段的限制，人们对限域效应的产生根源和催化作用机制尚缺乏统一的认识。本项目以合成受控的FeOx@C和FeOx@SiO2纳米限域体系为研究对象，通过控制合成条件，调变材料的结构参数，然后以原位穆斯堡尔谱为主要研究手段，结合其它分析方法对限域型FeOx催化剂晶相组成、价态以及氧化还原性能进行研究，并以NH3分解、F-T合成等为模型反应，揭示限域构型对催化性能的影响规律，阐明纳米限域效应的结构关联性和催化作用机制，为发展纳米制备科学以及高效催化剂的设计提供思路。

纳米限域催化是近年来催化领域研究的热点，是联系纳米科学技术与催化研究之间的桥梁。通过对限域型纳米催化剂的结构和催化性能进行研究，对于揭示纳米材料构效关系具有重要的指导意义。本项目以限域型铁基纳米催化剂为研究对象，以穆斯堡尔谱为主要手段，结合其它分析方法对材料的物化性能进行了系统地研究，并进一步研究材料的催化性能，从而探讨限域型催化剂结构和催化性能的关系。本项目研究内容主要包含：利用Stöber法合成出结构规整的限域型FeOx@C，FeOx@SiO2@C等纳米复合催化剂，研究了材料热处理过程中结构和形貌的变化，揭示了FeOx-C-SiO2催化剂体系各组分之间的相互作用；以FeOx@SiO2@C为模板构筑了限域型FeOx@SiO2-mSiO2材料，研究了材料的吸附性能，并作为载体进一步构筑限域型铂催化剂，研究其在硝基芳香化合物选择性加氢反应中的催化性能；以化学溶液法合成纳米级MFe2O4（M=Zn 或 Co）催化剂，利用穆斯堡尔谱对Fe的价态、配位状态以及磁性等进行深入研究，并与介孔二氧化硅复合构筑限域型CoFe2O4@mSiO2材料，用于活化过一硫酸盐降解水溶液中的有机染料，表现出比负载型催化剂更高的催化性能。本项目的实施发展了纳米材料制备科学，推动了穆斯堡尔谱技术在限域型纳米催化剂研究中的应用，进一步探索了限域型纳米催化剂的构效关系，为高级氧化技术降解有机污染物高效催化剂的开发提供了新思路。