负载型纳米零价铁对硝基苯的还原及铁形态变化

以短孔道有序介孔氧化硅材料Zr-Ce-SBA-15为载体,采用等体积浸渍-气相还原法制备铁硅摩尔比为0.15的纳米零价铁复合材料NZVI/Zr-Ce-SBA-15。以硝基苯(NB)为目标污染物考察复合材料对环状硝基化合物的还原性能,并对复合材料中铁粒子的存在形态进行分析。结果表明,复合材料比未负载纳米零价铁对NB具有更好的还原性能。NB溶液初始浓度为20 mg/L,复合材料投加量为1 g/L,反应12 h时溶液中NB的去除率可达93.6%,苯胺为最终还原产物。反应前材料中的铁以α-Fe0的形式存在,反应后大部分以非晶态铁氧化物的形式附着在材料的铁颗粒表面。

Reduction of Nitrobenzene Using Nanoscale Zero-Valent Iron Supported on Mesoporous Silica and Ferric Species Variation

A novel platelet SBA-15(Zr-Ce-SBA-15) with short and parallel channels has been synthesized through hydrothermal routes.Fe(15％ Fe/Si atomic ratio) was loaded on Zr-Ce-SBA-15 via wet impregnation followed by H2 reduction process.Nitrobenzene (NB) was selected as a model compound to examine the reduction ability of supported and non-supported nanoscale zero-value iron (NZVI).Results indicate that the NZVI supported on the mesoporous material had much higher reduction reactivity for NB than that of non-supported NZVI.The removal efficiency of NB achieved to 93.6％ in the liquid conducted with this composite after 12 h of reaction,when the dosage of composite was 1 g/L,NB initial concentration was 20 mg/L.Aniline was the final reductive product.The NZVI supported on the mesoporous material existed in the form of body-centered cubic α-Fe0 before reaction.After reaction,the most of the iron particles existed in the form of amorphous iron oxide and still adsorbed on the surface of iron particles rather than dissolved in the solution.