过渡金属离子改性Na-13X分子筛对噻吩类硫化物的吸附性能与机理

Adsorption of Thiophenic Sulfur in Transition Metal Ion Modified Na-13X Zeolites

采用液相离子交换法制备Cu+-13X、Ni2+-13X和Co2+-13X吸附剂,利用XRD、FT-IR和Laser-raman等对其进行表征。在常温常压条件下,以含有噻吩、2-乙基噻吩和苯并噻吩的正己烷溶液为模拟汽油,通过静态吸附实验与动力学吸附实验研究了3种吸附剂对噻吩、2-乙基噻吩和苯并噻吩的吸附性能与机理,并采用Langmuir模型对静态吸附平衡数据进行拟合和Crank单孔扩散模型对动力学吸附数据进行拟合。实验结果表明过渡金属离子改性的分子筛对噻吩类硫化物有较高的吸附含量;改性后分子筛的选择吸附性能取决于吸附质与吸附剂之间的π络合作用和吸附剂的表面酸性,而受硫化物的空间位阻影响作用很小。

Cu^＋-13X, Ni^2＋-13X and Co^2＋-13X based adsorbents were prepared by liquid phase ion exchange method and characterized by means of XRD, FT-IR and Laser-raman. Thiophene（TP）, 2-ethylthiophene（2-ETP） and benzothiophene（BT） containing n-hexane as simulated fuel was used to study the adsorption capacity of these three adsorbents via static and kinetics adsorption experiments at room temperature and atmosphere pressure. The static adsorption equilibrium data were fitted by Langmuir model and the kinetic data were fitted by Crank diffusion model. The results show that the transition metal ions modified zeolites have higher adsorption capacity for thiophenic sulfur. Meanwhile, the performance of the modified zeolites is dependent on their surface acidity and the π-complexation between adsorbates and adsorbents, which is not affected by the steric hindrance of thiophenic sulfur.