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  • Adsorption/desorption kinet...
    Zhang, Xiaodong; Yang, Yang; Lv, Xutian; Wang, Yuxin; Liu, Ning; Chen, Dan; Cui, Lifeng

    Journal of hazardous materials, 03/2019, Letnik: 366
    Journal Article

    Display omitted •Micro-mesoporous UiO-66 was synthesized with P123 as structure-directing agent.•Micro-mesoporous UiO-66 shows 2.6 times toluene adsorption capacity of UiO-66.•Micro-mesoporous structure improves the mass transfer rate and adsorption capacity.•Efficient regeneration of exhausted adsorbent was achieved by heating. In this work, micro-mesoporous UiO-66 was successfully prepared with P123 (EO20PO70EO20) as structure-directing agent by a simple solvothermal method. Adsorption/desorption kinetics of gaseous toluene over pristine UiO-66 and micro-mesoporous UiO-66 were investigated by breakthrough experiments, toluene vapor adsorption isotherm measurements and temperature programmed desorption (TPD) experiments. The interactions between toluene and UiO-66 samples were assessed through the Henry’s law constant (KH) and the isosteric adsorption heat (ΔHads). The micro-mesoporous UiO-66 crystal demonstrated 2.6 times toluene adsorption capacity of the pristine UiO-66 when the P123/Zr4+ molar ratio was 0.2. Results showed that micropore adsorption was the main adsorption process and the larger pores in micro-mesoporous UiO-66 increased molecular diffusion rate and reduced the mass transfer resistance. This result indicated that micro-mesoporous structures and defect sites had a positive effect on toluene molecules capture. The breakthrough times and the working capacities decreased with the increase of the relative humidity and adsorption temperature. A good thermal stability and reproducibility were revealed over the micro-mesoporous UiO-66 in this paper.