苯在改性活性炭上的脱附活化能

采用浸渍法制备了KH560/改性活性炭、1706/改性活性炭和A172/改性活性炭等3种活性炭，并利用程序升温脱附技术测定了苯在这3种改性活性炭上的脱附活化能. 结果表明，苯在经改性的活性炭上的脱附活化能均大于其在未改性活性炭上的脱附活化能，表明用有机硅烷改性活性炭可以提高其对苯的吸附能力. IGC分析结果表明，经硅烷改性的活性炭的特殊作用吸附自由能DGs均小于原始活性炭的DGs，这4种活性炭表面与苯的特殊作用吸附自由能DGs大小顺序与苯在这些活性炭上的脱附活化能大小顺序正好相反，这表明DGs越小，吸附质与活性炭表面形成的吸附越牢固，吸附质从其表面脱附所需的活化能越大.

Activation Energy for Desorption of Benzene on Modified Activated Carbons

This work mainly involves the study of activation energy of benzen desorption on modified activated carbons.Three kinds of activated carbons such as KH560/activated carbon,1706/activated carbon,and A172/activated carbon were prepared by means of the surface modification of organic silicon alkyl.Temperature-programmed desorption(TPD)experiments were conducted to measure the TPD curves of benzene on the activated carbons and estimate the activation energy for desorption of benzene on the modified activated carbons.The results showed that the activation energy for desorption of benzene on the KH560/activated carbon,1706/activated carbon and A172/activated carbon separately was 25.968,23.134 and 18.076 kJ/mol,which were higher than that on unmodified activated carbon,17.911 kJ/mol.It indicated that the use of organic silicon alkyl to modify the surfaces of activated carbon could improve its adsorption of benzene.The results of inverse gas chromatography(IGC)showed that specific interaction free energy for adsorption of benzene on the activated carbons was negative,which meant that this adsorption was spontaneous,the specific interaction free energy for adsorption of benzene on the modified activated carbons was smaller than that on the unmodified activated carbon,and the smaller the specific interaction free energy,the higher the activation energy required for the desorption of benzene on activated carbon.