铈负载改性天然沸石催化臭氧氧化水中青霉素G

以改性天然沸石(NZ)为载体,采用等体积浸渍法制备Ce负载天然沸石催化剂(Ce-NZ),将其应用于催化臭氧氧化水中青霉素G(PCN)。比表面积(BET)、扫描电镜-能谱(SEM-EDS)、透射电镜(TEM)和X射线衍射(XRD)表征结果表明,Ce-NZ催化剂保持了天然沸石的表面结构,CeO₂均匀负载在沸石载体的表面。Ce-NZ催化臭氧氧化水中PCN结果显示,催化剂具有良好的活性,在PCN初始浓度为50 mg/L,臭氧投加量为6 mg/min,反应时间为2 h时,4%Ce-NZ催化剂对PCN的去除率为31%,比单独臭氧氧化提高了22%。随着Ce负载量的增加,催化剂的催化活性提高有限,最佳Ce负载量为4%;溶液初始pH对反应有显著影响,提高溶液pH可以提高催化氧化效率;制备的Ce-NZ催化剂稳定性较好,重复使用10次后催化活性没有明显降低。

Catalytic ozonation of penicillin G in aqueous phase using modified natural zeolite supported cerium

Cerium-loaded treated nature zeolite (Ce-NZ) was prepared by equal volume impregnation method and was used as a catalyst for the ozonation of Penicillin G (PCN) in aqueous solution.The catalyst was characterized by particle surface area analysis (BET), scanning electron microscopy combined with energy dispersive spectrum (SEM-EDS), transmission electron (TEM) and X-ray diffraction (XRD). Characterizations results suggested that the prepared samples retained the surface structure of natural zeolite and the CeO2 particle was evenly loaded on the surface of zeolite supports. Ce-NZ catalytic ozonation of PCN in water showed that the catalyst had good catalytic activity. Under the conditions of PCN concentration 50 mg/L, ozone dosage 6 mg/min and reaction time 2 h, the mineralization efficiency of 4% Ce-NZ catalyst for PCN catalytic ozonation reached 31%, 22% higher than ozonation reaction alone. The catalytic activity of the samples slowly increased with metal loading amount and the 4% Ce loading amount was chosen as the optimum condition. The initial pH of the solution also had significant effect on the reaction, and the catalytic oxidation removal rate increased with the increasing of pH. The prepared Ce-NZ catalyst had high stability, and no marked difference of catalytic activity was seen after 10 times repeated use.