改性活性碳纤维制备及脱除NO的实验研究

活性炭纤维(activated carbon fiber,ACF)具有很高的比表面积和良好的孔结构,孔径分布较窄。为进一步提高活性碳纤维的脱硝性能,并揭示脱硝机制,采用H2O2,KMnO4/NaOH,NaClO/KOH对ACF进行改性处理,用于燃煤污染物NO的脱除。经过改性处理后,ACF的比表面积和孔容都有不同程度的下降,平均孔径有一定的增大。经X射线光电子能谱法分析表面官能团发现,经过改性处理后ACF表面各类含氧官能团有一定的增加。实验分析了改性ACF对NO的脱除机制,认为脱除机制是由以物理吸附为主的初期阶段和以化学吸附氧化为主的后期阶段构成,且化学吸附阶段,ACF表面化学官能团的催化氧化作用使NO氧化为中间产物NO2,提高了NO脱除效果。结果表明,用摩尔浓度比为0.03 0.1的KMnO4/NaOH对活性炭进行氧化改性可以获得最佳的NO脱除效果。

Experimental Study of NO Removal by Modified Activated Carbon Fiber

Activated carbon fiber(ACF) has high specific surface area,good pore structure and narrow pore size distribution.To increase the denitration efficiency,ACF was modified with H2O2,KMnO4/NaOH and NaClO/KOH.It is found that the specific surface area and pore volume decrease at different degrees,while the average pore diameter increases after modification.X-ray photoelectron spectrometry(XPS) analysis indicates that all kinds of oxygenous groups on the surface of the modified ACFs increase to a certain extent.The removal mechanism of NO by the modified ACFs includes the early stage dominated by physical adsorption and the following stage dominated by chemical adsorption and oxidation.During the chemical adsorption,NO is oxidized into NO2 by the catalytic functional groups on the surface of ACF,which accelerates the removal of NO.The results demonstrate that ACF modified by KMnO4/NaOH with the molar concentration ratio of 0.03 0.1 gain the best performance in NO capture.