石墨烯改性MCM-41负载铁复合材料的制备及其催化降解苯酚废水的研究
发布时间：2018-07-23 20:32
【摘要】：非均相Fenton法在反应过程中产生的·OH自由基具有强氧化性,是高级氧化技术中去除难降解有机物的有效手段的一种。本文以非均相Fenton技术为基础,制备多种负载型催化剂,多方位研究了催化剂对苯酚的降解效果等。本文采用浸渍法制备了以MCM-41和A1203为载体的催化剂,负载铁性和铜性的活性金属,筛选出MCM-41载体和Fe(NO3)3·9H2O活性成分。采用改进的Hummers法制备出氧化石墨烯(GO),利用高温回流法制备出石墨烯改性MCM-41分子筛负载铁金属催化剂,比较了Al-MCM-41-Fe、gh-Al-MCM-41-Fe和gh-MCM-41-Fe三种催化剂对苯酚降解效果的影响,利用SEM、比表面积、XRD表征手段对催化剂的化学价态、形貌进行分析。结果表明：gh-Al-MCM-41-Fe催化剂具有介孔结构,石墨烯加入后颗粒粒径减小,反应90min, pH在3.0时,苯酚降解率100%,COD去除率达到62.16%,铁溶出为0.06 mgoL-1,并且拓宽pH范围,降低铁溶出,减小了二次污染。采用另一种方法水热晶化法制备石墨烯改性MCM-41分子筛负载铁金属催化剂gh-MCM-41-Fe,对材料形貌、结构、官能团进行了SEM、 TEX、XRD、XPS等表征,并考察了材料制备工艺及反应条件。结果表明：制备的gh-MCM-41-Fe催化剂相比MCM-41-Fe具有更大的比表面积和孔容,有更好的介孔分子筛结构,并且氧化石墨烯在制备过程中热还原为石墨烯,其所负载金属呈α-Fe2O3型态晶体。当pH=3.0,石墨烯负载量为30 mL,铁离子负载量为5%,焙烧温度为550-550℃,催化剂投加量0.5 g·L-1,苯酚初始浓度100 mg·L-1, H2O2初始浓度9.8mmol·L-1, T=298 K时,反应90 min, gh-MCM-41-Fe对苯酚降解率接近100%,COD和TOC去除率分别达到63%和38.89%,铁溶出浓度为0.825 mg·L-1,表观活化能为18.43 kJ·mol-1,反应符合准一级动力学模型。相比MCM-41-Fe催化剂,提高了催化效能,石墨烯的掺杂降低了铁溶出,减少二次污染,并且研究还发现草酸和腐殖酸的添加会抑制苯酚的降解。
[Abstract]:The hydroxyl radical produced by heterogeneous Fenton process has strong oxidation property and is an effective method to remove refractory organic compounds in advanced oxidation technology. In this paper, based on heterogeneous Fenton technology, various supported catalysts were prepared and the degradation efficiency of phenol was studied. In this paper, the active metals supported on MCM-41 and A1203 supported on iron and copper were prepared by impregnation method. The active components of MCM-41 and Fe (NO3) 3 9H2O were screened out. Graphene oxide (GO), was prepared by modified Hummers method and graphene modified MCM-41 molecular sieve was prepared by high temperature reflux method. The effects of three kinds of catalysts, Al-MCM-41-Fefeng-Al-MCM-41-Fe and gh-MCM-41-Fe, on the degradation of phenol were compared. The chemical valence and morphology of the catalyst were analyzed by means of SEM, specific surface area and XRD. The results show that the catalyst has mesoporous structure, and the particle size decreases after the addition of graphene. When the reaction time is 90 min and pH is 3.0, the degradation rate of phenol reaches 62.16% and the iron dissolution is 0.06 mgoL ~ (-1), and the range of pH is widened, the iron dissolution is reduced, and the secondary pollution is reduced. Graphene modified MCM-41 zeolites were prepared by hydrothermal crystallization method. The morphology, structure and functional groups of the materials were characterized by SEM, TEXX RDX XPS, and the preparation process and reaction conditions were investigated. The results show that the prepared gh-MCM-41-Fe catalyst has larger specific surface area, larger pore volume and better mesoporous molecular sieve structure than MCM-41-Fe, and graphene oxide is thermally reduced to graphene, and the supported metal is 伪 -Fe _ 2O _ 3 crystal. When pH is 3.0, the loading amount of graphene is 30 mL, the loading amount of iron ion is 5, the calcination temperature is 550-550 鈩，
本文编号：2140559
[Abstract]:The hydroxyl radical produced by heterogeneous Fenton process has strong oxidation property and is an effective method to remove refractory organic compounds in advanced oxidation technology. In this paper, based on heterogeneous Fenton technology, various supported catalysts were prepared and the degradation efficiency of phenol was studied. In this paper, the active metals supported on MCM-41 and A1203 supported on iron and copper were prepared by impregnation method. The active components of MCM-41 and Fe (NO3) 3 9H2O were screened out. Graphene oxide (GO), was prepared by modified Hummers method and graphene modified MCM-41 molecular sieve was prepared by high temperature reflux method. The effects of three kinds of catalysts, Al-MCM-41-Fefeng-Al-MCM-41-Fe and gh-MCM-41-Fe, on the degradation of phenol were compared. The chemical valence and morphology of the catalyst were analyzed by means of SEM, specific surface area and XRD. The results show that the catalyst has mesoporous structure, and the particle size decreases after the addition of graphene. When the reaction time is 90 min and pH is 3.0, the degradation rate of phenol reaches 62.16% and the iron dissolution is 0.06 mgoL ~ (-1), and the range of pH is widened, the iron dissolution is reduced, and the secondary pollution is reduced. Graphene modified MCM-41 zeolites were prepared by hydrothermal crystallization method. The morphology, structure and functional groups of the materials were characterized by SEM, TEXX RDX XPS, and the preparation process and reaction conditions were investigated. The results show that the prepared gh-MCM-41-Fe catalyst has larger specific surface area, larger pore volume and better mesoporous molecular sieve structure than MCM-41-Fe, and graphene oxide is thermally reduced to graphene, and the supported metal is 伪 -Fe _ 2O _ 3 crystal. When pH is 3.0, the loading amount of graphene is 30 mL, the loading amount of iron ion is 5, the calcination temperature is 550-550 鈩，
本文编号：2140559
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