Cr-Ce/Al_2O_3催化剂对挥发性有机物的催化降解

Catalytic degradation of volatile organic compounds over Cr-Ce/Al_2O_3 catalysts

采用共沉淀法制备了一系列不同铬铈负载量和铬铈负载比例的Cr-Ce/Al_2O_3催化剂,采用XRD、BET、NH_3-TPD以及H_2-TPR对所制得的催化剂进行表征。在空速为15 000 h^(-1)、挥发性有机物体积分数为1 500μL·L^(-1)的条件下,于固定床反应器上考察了催化剂在三氯乙烯(TCE)催化氧化降解反应中的催化活性。实验结果表明,Cr-Ce/Al_2O_3(5%,10%)系列催化剂具有较好的低温催化降解三氯乙烯活性,其中Cr-Ce/Al_2O_3(5%,10%)活性最高,在271.3℃时可将尾气中90%的三氯乙烯降解。催化剂反应800 min后活性仅有轻微下降,说明该催化剂具有较好的稳定性。此外,将该催化剂用于其他VOCs催化降解反应中同样具有较好的活性,在350℃时可以将尾气中VOCs完全降解。

A series of Cr-Ce/Al2O3 catalysts with different amount and ratio of Cr-Ce oxides were prepared by coprecipitation method,the obtained catalysts were characterized by XRD,BET,NH3-TPD and H2-TPR.The catalytic activity of these catalysts were tested for catalytic oxidation of trichloroethylene（TCE） on a fixed bed reactor with a GHSV of 15 000 h^-1 and VOCs volume fraction of 1 500 μL·L^-1.The results revealed that Cr-Ce/Al2O3 catalysts present high catalytic activity for the low temperature catalytic oxidation of TCE,and Cr-Ce/Al2O3（5%,10%） catalyst is identified as the most active catalyst,and 90% of trichloroethylene degradation at271.3 ℃.The activity of the catalyst after 800 min reaction only slightly decreased,indicating that the catalyst has good stability.In addition,the catalyst used to catalyze the degradation of other VOCs has the same good activity,and the exhaust gas can be completely degraded VOCs at 350 ℃.