磷钨酸负载锆基金属有机骨架PTA@MOF-808的制备及其吸附脱硫性能

Preparation of phosphotungstic acid loaded Zr-based metal-organic framework PTA@MOF-808 and its adsorption desulfurization performance

利用原位合成法将磷钨酸(PTA)负载于锆基金属有机骨架材料(MOFs)上,通过X射线衍射(XRD)、红外(FT-IR)、氮气吸附-脱附、扫描电镜(SEM)以及热重(TG)等表征证实了PTA@MOF-808复合材料的成功制备。通过制备的PTA@MOF-808吸附剂在模型油中对苯并噻吩(BT)的静态吸附脱硫实验,考察了PTA负载量、温度、油剂比、模型油硫含量以及不同有机硫对复合材料吸附脱硫性能的影响。实验结果表明:PTA的引入致使MOF-808对正辛烷中BT的吸附量提高了约2倍。PTA@MOF-808吸附速率快、在300 s时基本吸附完全,并且其第6次循环使用吸附BT的吸附量为首次吸附量的86%。最后,通过PTA@MOF-808对BT吸附的动力学和热力学研究表明该吸附过程符合准二级动力学模型,吸附过程包含物理吸附与化学吸附。

The phosphotungstic acid(PTA)was loaded on the zirconium-based metal organic framework materials(MOFs)by in-situ synthesis,and X-ray diffraction(XRD),infrared(FT-IR),nitrogen adsorption-desorption,scanning electron microscope(SEM)and thermogravimetric(TG)confirmed the successful preparation of PTA@MOF-808 composite material.The effects of PTA amounts,temperature,oil-adsorbent ratio,model oil sulfur content and type of sulfide on the adsorption desulfurization performance of PTA@MOF-808 adsorbents were investigated by the static adsorption desulfurization experiments.The results showed that the introduction of PTA increased the adsorption capacity of MOF-808 for benzothiophene(BT)by 2 times.PTA@MOF-808 has a fast adsorption rate and basically reaches adsorption equilibrium at 300 s.After 6 cycles of removal of BT,the adsorption capacity was still 86%of the first adsorption capacity.Finally,the kinetic and thermodynamic of BT􀤃􀤃􀤃􀤃􀤃􀤃􀤃􀦃adsorption onto PTA@MOF-808 were studied.The results showed that the adsorption process followed a quasisecond-order kinetics model and included physical adsorption and chemical adsorption.