Fe/ZrO2催化剂气相催化裂解1,1,2-三氯乙烷脱氯化氢性能

采用浸渍法制备系列不同负载量的Fe/ZrO2催化剂,用于气相催化裂解1,1,2-三氯乙烷脱氯化氢性能的研究。结果表明,反应温度为350℃时,负载Fe质量分数为1%的1Fe/ZrO2催化剂催化活性最好,1,1,2-三氯乙烷转化率约95.0%,顺式1,2-二氯乙烯选择性为91.0%,反应50h性能稳定不失活,1,1,2-三氯乙烷转化率约92.0%,顺式1,2-二氯乙烯选择性约90.0%。单一ZrO2载体上的脱氯反应初始转化率为90.0%,经过1h反应即快速失活。ZrO2催化剂失活归因于ZrO2表面酸性较强导致积炭。对于Fe/ZrO2催化剂,Fe物种不但提供新的活性位点,而且降低了催化剂的表面强酸性中心,使催化剂催化活性更高,稳定性更好。

Gasphase dehydrochlorination of 1,1,2-trichloroethane over Fe/ZrO2 catalysts

A series of Fe/ZrO₂ catalysts with different loading amount were prepared by an impregnation method and tested for the gas phase dehydrochlorination of 1,1,2-trichloroethane(TCE) to synthesize cis-1,2-dichloroethylene(cis-DCE).Results showed that 1Fe/ZrO₂ catalyst with Fe mass content of 1% showed the best activity and stability in 50 h,with 1,1,2-trichloroethane conversion of 95.0% and cis-DCE selectivity of 90.0% when reaction temperature was 350 ℃.The pristine ZrO₂ catalyst had high initial activity with 1,1,2-trichloroethane conversion of 90.0%,but it deactivated after 1 h of reaction.The results reveal that strong acid sites on ZrO₂ surface are responsible for the deposition of coke and consequently catalyst deactivation.The addition of Fe in Fe/ZrO₂catalysts decreases amounts of strong acid sites and generates new active sites to enhance activity and stability of catalysts.