Enhanced desulfurization characteristics of Cu-KIT-6 for thiophene

Mesoporous KIT-6 molecular sieves containing Cu (Cu-KIT-6) to the extent of 5 to 15 wt% were synthesized by ultrasound assisted incipient wetness impregnation (IWI) for the first time and used as the adsorbents for desulfurization of model fuel at a temperature range of 30-90 degrees C. The sorbents were characterized by XRD, N-2 adsorption, TPR, FT-IR HRTEM, SEM and XPS techniques. The result revealed that Cu-KIT-6 adsorbent with a copper content up to 10 wt% can still retain the uniform mesoporous framework of KIT-6 and the proposed ultrasonic method gives highest Cu dispersion without segregation than impregnated method, which improved significantly the adsorptive desulfurization performance of the sorbents. The adsorption capacities of the sorbents at 70 degrees C follow the order 10 Cu-KIT-6 (33.5 mg-S/g) > 5 Cu-KIT-6 (31.1 mg-S/g) >10 Cu/KIT-6 (263 mg-S/g) > 15 Cu-KIT-6 (19.5 mg-S/g) > (0.5 mg-S/g) KIT-6. Moreover, the experimental equilibrium data have been analyzed using the linearized form of Langmuir and Freundlich isotherms and the Langmuir isotherm was found to provide the best theoretical correlation of the experimental data for the adsorption of thiophene. (C) 2014 Elsevier Inc. All rights reserved.