Moma John, Baloyi Jeffrey, Ntho Thabang
Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand Johannesburg South Africa
Advanced Materials Division, MINTEK 200 Malibongwe Drive, Randburg 2125 South Africa.
RSC Adv. 2018 Aug 24;8(53):30115-30124. doi: 10.1039/c8ra05825c.
A facile method for synthesizing Al/Fe pillared clays (PILCs) from natural bentonite clay, by using ultrasonic treatment during the aging and intercalation steps, has been established. Single metal (Fe-PILCs and Al-PILCs) and mixed metal (Al/Fe-PILCs, with varying compositions of the pillaring precursors) pillared clays were prepared and characterized with a combination of chemical and instrumental methods. The pillared clays were evaluated as catalysts in the catalytic wet air oxidation (CWAO) of phenol and the mixed metal pillared clay catalysts, especially with an Al/Fe ratio of 3 : 1, were found to be highly active and stable, with superior properties such as surface areas, basal spacing, high porosity and thermal stability. The catalysts could also be reused several times without significant loss of activity. The results of the study show that Al/Fe-pillared clay catalysts are effective catalysts for the oxidation of phenol and removal of TOC in aqueous solutions. The main intermediate products in the CWAO of phenol were hydroquinone, pyrocatechol, and benzoquinone and oxalic, formic, malonic, oxalic, malonic and maleic acids.
已经建立了一种从天然膨润土合成铝/铁柱撑粘土（PILCs）的简便方法，即在老化和插层步骤中使用超声处理。制备了单金属（铁柱撑粘土和铝柱撑粘土）和混合金属（铝/铁柱撑粘土，具有不同组成的柱撑前驱体）柱撑粘土，并结合化学和仪器方法对其进行了表征。将柱撑粘土作为苯酚催化湿式空气氧化（CWAO）的催化剂进行了评估，发现混合金属柱撑粘土催化剂，特别是铝/铁比为3∶1的催化剂具有高活性和稳定性，具有诸如表面积、层间距、高孔隙率和热稳定性等优异性能。该催化剂还可以重复使用多次而活性没有明显损失。研究结果表明，铝/铁柱撑粘土催化剂是用于氧化苯酚和去除水溶液中总有机碳的有效催化剂。苯酚CWAO的主要中间产物是对苯二酚、邻苯二酚、苯醌以及草酸、甲酸、丙二酸、草酸、丙二酸和马来酸。
