基于Cu基双金属合金纳米晶的Rochow反应及其催化机理研究

Dimethyldichlorosilane (M2) was the most important monomer in organosilane industry, which is synthesized via Rochow reaction with gas MeCl and solid Silicon in the presence of copper-based catalysts. Thus, developing a novel and efficient catalyst system for Rochow reaction and exploring the mechanism are still desirable. Currently, nanomaterials are the research focus in the international academic field of catalysis. However, the possibility of employing the nanocrystals as M2 production catalysts have not been investigated so far. On this basis, this project will carry out the following work: First, the bimetallic CuM(M=Zn、Sn、Mg、Ag、Au) alloy nanocrystals with uniform size, shape and composition will be synthesized via controlling the synthesis parameters efficiently. Second, they would be deposited on the silicon wafer, and the obtained supported copper nanocatalysts will be employed to apply in the Rochow reaction to explore the catalytic behavior. The effects of size, morphology, and composition of copper nanocatalysts on the catalytic properties (conversion of Si wafer and M2 selectivity) will be investigated, via which the structure-activity dependence could be established and thus the real catalytic mechanism would be revealed. Finally, based on these results, the copper-based bimetallic nanocatalyst with high efficiency would be developed and the excellent catalytic properties could be achieved. The exploration of the Rochow catalytic reaction in this project will be helpful in the design and fabrication of other low cost and highly efficient copper-based catalytic systems for organosilane industry.

二甲基二氯硅烷（M2）是有机硅行业最重要的单体，工业上主要通过Rochow反应来制备，即在铜催化剂的作用下，氯甲烷（MeCl）和硅粉（Si）发生直接取代反应。因此，开发新型高效催化体系及探索其催化机理仍然是一项具有理论和实际应用价值的研究课题。纳米催化材料是当今国际学术界的研究热点，然而迄今为止，纳米晶在Rochow反应的应用研究还鲜有报道。基于此，本项目拟开展以下基础研究工作：（1）通过调控合成条件，制备尺寸、形貌和组成可控的Cu基双金属合金纳米晶CuM(M=Zn、Sn、Mg、Ag、Au)；（2）将其直接沉积于硅片上用于Rochow反应性能评价，明晰催化剂结构（尺寸、晶面和组成）与催化特性（硅片转化率和M2选择性）的“构效关系”及其内在机理；（3）在此基础上，开发出高效纳米铜基双金属催化剂，实现催化性能的最优化。本课题的完成将为其它高效低成本铜催化体系的研制奠定基础。

二甲基二氯硅烷（M2）是有机硅行业最重要的单体，工业上主要通过Rochow反应来制备，即在铜催化剂的作用下，氯甲烷（MeCl）和硅粉（Si）发生直接取代反应，目前开发基于Rochow反应的新型高效催化体系及探索其催化机理仍然具有重要的意义。基于此，本项目采用液相合成体系，制备了形貌和组成可控的Cu基纳米催化材料，系统表征了其结构征；用固定床评价了其Rochow反应性能，明晰了Cu催化剂结构与M2选择性和收率的“构效关系”，结合动力学分析和密度泛函计算，推测出了催化机理；在此基础上，开发出了高效纳米铜基催化剂，实现了目前M2选择性和收率的最优化，该课题为其它高效低成本铜催化体系的研制奠定了坚实的基础。