不同孔径硅胶负载的铯盐对1,1,2-三氯乙烷脱HCl的影响

Dehydrochlorination of 1,1,2-trichloroethane by cesium salt loaded silica gel with different pore sizes

大孔硅胶由于其孔径和孔容大,能够负载更多的碱量,而且有机物分子在大孔道中能更快速扩散、更容易与碱性活性中心接触发生表面吸附与反应,以提高1,1,2-三氯乙烷(TCE)脱HCl的反应活性和产物偏二氯乙烯(VDC)的选择性。采用等体积浸渍法制备系列不同孔径硅胶负载的Cs NO3、Cs2CO3和Cs Cl催化剂,用于TCE气相脱HCl制VDC反应中。结果表明:催化剂活性随载体硅胶孔径和催化剂碱性的增大而提高。在400℃下,与Cs Cl/20A相比,Cs NO3/278A催化TEC的转化率提高了35%,VDC的选择性提高了13%。催化剂稳定性测试表明:Cs Cl/200A表现出较好的稳定性,在400℃下可连续稳定17 h,有较好的应用前景。

Owing to the large pore diameter and volume,macro porous silica gel can load more alkali,and organic matter can spread more quickly in the catalyst pore and contact more easily with the active sites,which can improve the 1,1,2-trichloroethane dehydrochlorination reactivity.A series CsNO 3,Cs 2CO 3 and CsCl catalysts supported on silica gel with different pore sizes were prepared through equivalent volume impregnation method,and applied to the catalytic dehydrochlorination of 1,1,2-trichloroethane.Results showed that the catalytic performance increased with increasing pore size of silica gel and the basicity of catalysts.Comparing with CsCl/20A at 400℃,the 1,1,2-trichloroethane conversion over CsNO 3/278A raised by 35%,vinylidene chloride selectivity increased 13%,respectively.The stability test showed that at 400℃CsCl/200A had a satisfactory result of 17 h,and exhibited a promising application.