| 活性炭孔结构和表面化学性质对吸附硝基苯的影响 |
| 摘要点击 4354 全文点击 3775 投稿时间：2007-05-28 修订日期：2007-07-09 |
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| 中文关键词 活性炭 HNO3氧化 热处理 硝基苯 吸附 |
| 英文关键词 activated carbon HNO3 oxidation heat treatment nitrobenzene adsorption |
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| 中文摘要 |
| 通过对活性炭HNO3氧化及随后的N2气氛中热处理，研究了活性炭性质对其吸附硝基苯性能的影响.以低温液氮(N2/77K)吸附测定活性炭的比表面积和孔容、孔径分布，以SEM观测活性炭表面形貌，以Boehm滴定、FTIR、零电荷点pHPZC测定及元素分析定量表征活性炭表面含氧官能团变化.结果表明，HNO3氧化可以显著改变活性炭表面化学性质，增加活性炭表面酸性含氧官能团数量，对活性炭孔隙结构影响不大.随后N2气氛中热处理可以造成活性炭表面酸性含氧官能团分解，外表面积增大，微孔烧蚀为中孔.硝基苯在活性炭上的吸附基本符合Langmuir方程.改性后活性炭对硝基苯的吸附容量明显改变，ACNO-T、ACraw、ACNO吸附容量分别为1?011.31、 483.09、 321.54 mg·g-1.较大的外表面积、适宜数量的中孔以及较少的酸性含氧官能团是ACNO-T对硝基苯表现出较高吸附容量的主要原因. |
| 英文摘要 |
| Commercial activated carbon was treated by HNO3 oxidation and then subsequently heat treated under N2 atmosphere. Effect of surface chemical properties and pore structure on the adsorption performance of nitrobenzene was investigated. N2/77K adsorption isotherm and scanning electron microscopy (SEM) were used to characterize the pore structure and surface morphology of carbon. Boehm titration, Fourier transform infrared spectroscopy (FTIR), the point of zero charge (pHPZC) measurement and elemental analysis were used to characterize the surface properties. The results reveal that HNO3 oxidation can modify the surface chemical properties，increase the number of acidic surface oxygen-containing groups and has trivial effect on the pore structure of carbon. Further heat treatment can cause the decomposition of surface oxygen-containing groups, and increase the external surface area and the number of mesopores. Adsorption capacity of nitrobenzene on ACNO-T, ACraw and ACNO was 1 011.31, 483.09 and 321.54 mg·g-1, respectively. Larger external surface area and the number of meso-pores, together with the less acid surface oxygen-containing groups were the main reason for the larger adsorption capacity ACNO-T. |
