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为解决传统铁基芬顿催化剂在水体通常酸碱(pH>6)条件下活性低的问题,采用简单共沉淀法制备了Cu掺杂的Al_2O_3类芬顿催化剂.通过X射线衍射(XRD)、X射线光电子能谱(XPS)和紫外可见(UV-vis)吸收光谱分析表明,Cu-Al_2O_3中铜掺杂的质量分数低于4.77%时,催化剂中铜主要以Cu~(2+)和Cu~+的形式共存于Al_2O_3的骨架结构中,形成Al—O—Cu键;过量的铜掺杂会导致外骨架铜物种如铜氧化物团簇的存在.以难降解有机污染物2-氯苯酚(2-chlorophenol,2-CP)和染料罗丹明B(Rhodamine B,Rh B)为目标污染物,对Cu-Al_2O_3的类芬顿催化性能进行了详细地研究.结果表明,骨架铜物种在中性温和条件下对2-CP和Rh B显示出很高的催化去除效率和稳定性,反应2 h,Cu-Al_2O_3(Cu质量分数4.77%)对2-CP的去除率达到54%,相应的TOC去除率达到49%,而铜离子溶出浓度仅为0.025 5 mg·L-1,而Cu-Al_2O_3(Cu质量分数7.58%)由于外骨架铜的存在导致催化活性增加缓慢和稳定性下降.ESR测试结果表明,·OH和HO_2~-/O_2~-·是反应中主要的活性物种.
In order to solve the problem that the traditional Fe-based Fenton catalyst has low activity in the condition of pH-6, the copper-doped Al_2O_3-based Fenton catalyst was prepared by a simple coprecipitation method.According to X-ray diffraction (XRD) X-ray photoelectron spectroscopy (XPS) and UV-vis absorption spectroscopy showed that the Cu content in Cu-Al 2 O 3 was below 4.77% ~ + Form coexist in the framework structure of Al 2 O 3 to form Al-O-Cu bonds. Excess copper doping will lead to the existence of exoskeleton copper species such as copper oxide clusters. In order to refractory organic pollutants 2-chlorophenol 2-chlorophenol (2-CP) and Rhodamine B (Rh B) as target pollutants, the Fenton-like catalytic activity of Cu-Al_2O_3 was studied in detail. Under mild conditions, 2-CP and Rh B showed high catalytic efficiency and stability. After 2 h reaction, the removal rate of 2-CP by Cu-Al 2 O 3 (Cu content 4.77%) reached 54% TOC removal rate of 49%, while the copper ion elution concentration of only 0.025 5 mg · L-1, and Cu-Al_2O_3 (Cu mass fraction of 7.58%) due to exoskeleton copper lead The catalytic activity increased slowly and the stability decreased.The results of ESR showed that · OH and HO_2 ~ - / O_2 ~ - were the main active species in the reaction.