Fe_(3)O_(4)@SPC类芬顿氧化降解苯酚

Fe_(3)O_(4)@SPC as catalyst for Fenton-like oxidative degradation of phenol

以钙基蒙脱石(Ca-MMT)为原料,采用一步层间模板法制备了Fe_(3)O_(4)@硅柱撑蒙脱石催化剂(Fe_(3)O_(4)@SPC)。通过XRD、FTIR、BET、SEM、TEM对其结构、形貌进行了表征,以苯酚为目标降解污染物,考察了Fe_(3)O_(4)@SPC的催化活性和稳定性,并推测了苯酚可能的降解路径。结果显示,Fe_(3)O_(4)@SPC晶面间距(d;)为3.30 nm,介孔平均孔径为4.47 nm,Fe_(3)O_(4)粒子主要分散在SPC的外表面。在苯酚质量浓度为0.10 g/L的100 m L溶液中,pH为2.5,催化剂质量浓度为0.5 g/L,H_(3)O_(4)投加量为0.20 m L,反应时间为120 min的最优条件下,苯酚的去除率为100%;催化剂经过5次循环使用后,苯酚的降解率仍保持在91.80%。通过GC-MS分析苯酚降解生成的中间体,结合叔丁醇猝灭实验发现,·OH氧化在非均相类芬顿催化氧化降解苯酚体系中起主导作用。

Fe_(3)O_(4)@silicon pillared montmorillonite catalyst (Fe_(3)O_(4)@SPC),characterized by XRD,FTIR,BET,SEM and TEM,was prepared by a one-step interlayer template method using calcium-based montmorillonite (Ca-MMT) as raw materials.The catalytic activity over phenol degradation as well as stability of synthesized Fe_(3)O_(4)@SPC were evaluated,while the possible degradation path was also investigated The characterization results indicated that Fe_(3)O_(4)@SPC exhibited a crystal plane spacing (d;) of 3.30 nm and an average mesoporous aperture of 4.47 nm with most of Fe_(3)O_(4)particles dispersed on the external surface of SPC.In regard to the catalytic performance,Fe_(3)O_(4)@SPC promoted the degradation of phenol to100%,and remained 91.80%even after the catalyst was recycled for 5 times under the optimal conditions with phenol mass concentration of 0.10 g/L (100 mL),pH of 2.5,mass concentration of catalyst of 0.5 g/L,H_(3)O_(4)dosage of 0.20 m L and reaction time of 120 min.Mechanism exploration by GC-MS analysis of intermediates generated in phenol degradation and tert-butanol quenching experiment suggested that·OH oxidation might play a key role in heterogeneous Fenton-like oxidative degradation of phenol system.