Heck Kimberly N, Wang Yehong, Wu Gang, Wang Feng, Tsai Ah-Lim, Adamson David T, Wong Michael S
Department of Chemical and Biomolecular Engineering, Rice University Houston TX 77005 USA
Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian China.
RSC Adv. 2019 Aug 28;9(46):27042-27049. doi: 10.1039/c9ra05007h. eCollection 2019 Aug 23.
1,4-dioxane, commonly used as a solvent stabilizer and industrial solvent, is an environmental contaminant and probable carcinogen. In this study, we explored the concept of using metal oxides to activate HO catalytically at neutral pH in the dark for 1,4-dioxane degradation. Based on batch kinetics measurements, materials that displayed the most suitable characteristics (high 1,4-dioxane degradation activity and high HO consumption efficiency) were ZrO, WO /ZrO, and CuO. In contrast, materials like TiO, WO, and aluminosilicate zeolite Y exhibited both low 1,4-dioxane degradation and HO consumption activities. Other materials (, FeO and CeO) consumed HO rapidly, however 1,4-dioxane degradation was negligible. The supported metal oxide WO /ZrO was the most active for 1,4-dioxane degradation and had higher HO consumption efficiency compared to ZrO. acetonitrile poisoning and FTIR spectroscopy results indicate different surface acid sites for 1,4-dioxane and HO adsorption and reaction. Electron paramagnetic resonance measurements indicate that HO forms hydroxyl radicals (˙OH) in the presence of CuO, and unusually, forms superoxide/peroxyl radicals (˙O ) in the presence of WO /ZrO. The identified material properties suggest metal oxides/HO as a potential advanced oxidation process in the treatment of 1,4-dioxane and other recalcitrant organic compounds.
1,4 - 二氧六环常用作溶剂稳定剂和工业溶剂，是一种环境污染物和可能的致癌物。在本研究中，我们探讨了在黑暗中利用金属氧化物在中性pH条件下催化活化羟基自由基（HO）以降解1,4 - 二氧六环的概念。基于批次动力学测量，表现出最适宜特性（高1,4 - 二氧六环降解活性和高羟基自由基消耗效率）的材料是ZrO、WO₃/ZrO和CuO。相比之下，像TiO₂、WO₃和Y型硅铝酸盐沸石等材料的1,4 - 二氧六环降解和羟基自由基消耗活性都很低。其他材料（如Fe₂O₃和CeO₂）能快速消耗羟基自由基，然而1,4 - 二氧六环的降解可忽略不计。负载型金属氧化物WO₃/ZrO对1,4 - 二氧六环降解最为活跃，与ZrO相比具有更高的羟基自由基消耗效率。乙腈中毒和傅里叶变换红外光谱结果表明，1,4 - 二氧六环和羟基自由基的吸附及反应存在不同的表面酸性位点。电子顺磁共振测量表明，羟基自由基在CuO存在下形成羟基自由基（˙OH），不同寻常的是，在WO₃/ZrO存在下形成超氧/过氧自由基（˙O₂⁻）。所确定的材料特性表明金属氧化物/羟基自由基可作为处理1,4 - 二氧六环及其他难降解有机化合物的潜在高级氧化工艺。
