纳米CuCl催化直接法合成三乙氧基硅烷

Direct Synthesis of Triethoxysilane Catalyzed by Nano CuCl

为研发高效的催化剂和深入认识直接法合成三烷氧基硅烷反应的机理,采用水热合成法制备了纳米CuCl催化剂,并用于催化乙醇与硅粉直接合成三乙氧基硅烷。探究了硅粉粒度、反应时间、硅粉与催化剂混合物预处理温度和预处理时间等因素对硅粉转化率、三乙氧基硅烷选择性的影响。结果表明:硅粉粒度为0.074 mm(200目)、反应时间为2 h、硅铜预处理温度和时间分别为260℃和8 h时催化效果最佳,硅粉转化率为93.6%,三乙氧基硅烷的选择性达99.6%。同时,结合X射线衍射(XRD)、扫描电镜(SEM)和X射线能谱(EDS)等表征结果,探讨了催化剂预活化和反应过程失活的内在作用机制。

In order to develop efficient catalysts and explore the reaction mechanism for the direct synthesis of trialkoxysilanes.nano-cuprous chloride catalysts were prepared by hydrothermal synthesis method and used to catalyze direct synthesis of triethoxysilane from ethanol and silicon powder.Influence of silicon powder size,reaction time,pretreatment temperature and time of the powder and catalyst mixture on conversion of silicon powder and selectivity of triethoxysilane was investigated.The results showed that the best reaction performance was achieved when the size of silicon powder was 0.074 mm(200 mesh),the reaction time was 2 h,the pretreatment temperature and time of silicon and copper were 260℃and 8 h respectively.At this condition,the conversion of silicon powder was 93.6%and the selectivity of triethoxysilane was 99.6%.Moreover,the intrinsic mechanism of catalyst preactivation and deactivation during reaction was discussed by combining characterization results such as X-ray diffraction(XRD),scanning electron microscopy(SEM)and X-ray energy dispersive spectroscopy(EDS).