三维有序大孔铈锰复合氧化物催化氧化VOCs

Three-dimensional Ordered Macropores Cerium-manganese Composite Oxides Catalyze the Oxidation of VOCs

挥发性有机物(VOCs)是大气污染的主要来源,也是石油化工企业需要重点控制处理的厂区污染物之一,而催化燃烧作为处理VOCs的有效技术之一,具有能耗低、处理效率高和无二次污染等优点。文章采用聚甲基丙烯酸甲酯(PMMA)硬模板法和过量浸渍法相结合,制备了一系列不同摩尔比的三维有序大孔铈锰复合氧化物,通过XRD、BET、SEM、XPS、H_(2)-TPR表征分析和催化燃烧测试等手段,研究了摩尔比对催化剂的微观形貌、氧化还原性能和催化活性的影响,最终确定了最佳摩尔比。结果表明,铈锰比为64(C6M4)时,铈锰复合氧化物催化剂显示出均一的三维有序大孔结构,其平均孔径达17.36 nm。同时,C6M4具有较高的Mn^(4+)含量和吸附氧浓度,表现出最佳的催化燃烧甲苯活性,其T_(50)、T_(90)分别为100℃和153℃。

Volatile organic compounds(VOCs)are the main source of air pollution,and are one of the pollutants that petrochemical enterprises need to control.As an effective technology for VOCs treatment,catalytic combustion has the advantages of low energy consumption,high treatment efficiency,and no secondary pollution.In this study,a series of 3DOM cerium manganese composite oxides with different molar ratios were prepared by PMMA template-excess impregnation method.The impact of molar ratio on the microtopography,redox properties and catalytic activity of the catalysts were investigated by XRD,BET,SEM,XPS,H_(2)-TPR and catalytic combustion test,and the optimal molar ratio was finally determined.The results shown that when the molar ratio of cerium-manganese reached 64(C6M4),the cerium-manganese composite oxide catalyst shows a uniform three-dimensional ordered macropores structure with an average pore size of 17.36 nm.Meanwhile,C6M4 has higher Mn^(4+)and adsorbed oxygen concentration,showing the best catalytic combustion activity of toluene,with T_(50) and T_(90) of 100℃and 153℃,respectively.