The Synthesis And Application Of USY@MnAl-LDHs Materials

According to the synthetic mechanism and condition of MnAl-LDHs,a bifunctional material USY@Mn₃O₄,with high metal dispersion and catalytic activity,was innovatively prepared in the present study via one-pot growing MnAl-LDH on USY zeolite crystals and subsequent calcination.USY zeolite and manganese oxide both have shown great potential in the field of organic wastewater treatment.Thus,the USY@Mn₃O₄ material was evaluated in the ozonation of phenol in wastewater.The details were as follows:In the first part,based on the synthetic mechanism of hydrotalcite,the USY zeolite with Si/Al ratio of 3 was applied as the parent material.The synthetic parameters,including temperature,time,pH value and metal loading amount,were investigated firstly,because the synthetic condition could affect the properties of the obtained USY@MnAl-LDHs material.XRD,SEM and BET technique were applied to characterize USY@MnAl-LDHs material,which helped to determine the optimal synthetic condition.Finally,USY@MnAl-LDHs was calcined to give the bifunctional USY@Mn₃O₄ catalyst.In the second part,in contrast to the USY@MnAl-LDHs materials,Al₂O₃ was selected as the support,and the synthetic parameters of the catalyst Al₂O₃@MnAl-LDHs were carefully investegated to obtain the optimal synthetic condition by means of XRD and SEM techniques.Different from USY zeolite,the Al₂O₃ was easier to provide aluminum sources,which resulted in lower synthetic temperature and shorter time The results suggested that different parent will affect the formation of manganese aluminum hydrotalcite.In the third part,according to the reported application of Y zeolite and manganese oxide in wastewater treatment,USY@Mn₃O₄ was evaluated in the phenol degrading reaction in this present study.And USY@Mn₃O₄ showed higher activity in comparison to other catalysts or materials prepared by impregnation method.