Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs 06269-3060, USA.
J Phys Chem A. 2009 Feb 26;113(8):1523-30. doi: 10.1021/jp807631w. Epub 2009 Jan 29.
The catalytic degradation of organic dye (methylene blue, MB) has been studied using green oxidation methods (tertiary-butyl hydrogen peroxide, TBHP, as the oxidant with several doped mixed-valent and regular manganese oxide catalysts in water) at room and higher temperatures. These catalysts belong to a class of porous manganese oxides known as octahedral molecular sieves (OMS). The most active catalysts were those of Mo(6+)- and V(5+)-doped OMS. Rates of reaction were found to be first-order with respect to the dye. TBHP has been found to enhance the MB decomposition, whereas H(2)O(2) does not. Reactions were studied at pH 3-11. The optimum pH for these reactions was pH 3. Dye-decomposing activity was proportional to the amount of catalyst used, and a significant increase in catalytic activity was observed with increasing temperature. X-ray diffraction (XRD), energy dispersive spectroscopy (EDX), and thermogravimetric analysis (TGA) studies showed that no changes in the catalyst structure occurred after the dye-degradation reaction. The products as analyzed by electrospray ionization mass spectrometry (ESI-MS) showed that MB was successively decomposed through different intermediate species.
采用绿色氧化法（叔丁基过氧化氢（TBHP）作为氧化剂，几种掺杂的混合价和常规氧化锰催化剂在水中）在室温及更高温度下研究了有机染料（亚甲基蓝，MB）的催化降解。这些催化剂属于一类称为八面体分子筛（OMS）的多孔锰氧化物。最活跃的催化剂是 Mo（6+）和 V（5+）掺杂的 OMS。反应速率与染料呈一级关系。发现 TBHP 增强了 MB 的分解，而 H（2）O（2）则没有。在 pH 3-11 下研究了反应。这些反应的最佳 pH 值为 pH 3。染料分解活性与所用催化剂的量成正比，并且随着温度的升高，观察到催化活性显著增加。X 射线衍射（XRD）、能谱（EDX）和热重分析（TGA）研究表明，在染料降解反应后，催化剂结构没有发生变化。通过电喷雾电离质谱（ESI-MS）分析的产物表明，MB 通过不同的中间物种依次分解。
