Barghi Bijan, Mõistlik Tanel, Raag Anastassia, Volokhova Maria, Reile Indrek, Seinberg Liis, Mikli Valdek, Niidu Allan
Virumaa College School of Engineering, Tallinn University of Technology, Järveküla 75, Kohtla-Järve 30322, Estonia.
National Institute of Chemical Physics and Biophysics, Akadeemia 23, Tallinn 12618, Estonia.
ACS Omega. 2024 May 23;9(22):23329-23338. doi: 10.1021/acsomega.3c09971. eCollection 2024 Jun 4.
This study aims to determine the catalytic activity and stability of ligand-modified UiO-66 with different functional groups (-NO, -OH) in deep oxidative desulfurization from a model fuel (MF). The planar sulfur compounds included dibenzothiophene (DBT), 2-methylbenzothiazole (2-MB), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) in -dodecane as the fuel phase. The synthesized functionalized metal-organic framework (MOF) samples were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR), proton nuclear magnetic resonance (H NMR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), nitrogen adsorption-desorption analysis, and microwave plasma-atomic emission spectrometer (MP-AES). The experiment assessment and desulfurization reaction optimization were carried out by the central composite design methodology. Response surface methodology and analysis of variance were employed to evaluate the individual process factors, their interactions, and sulfur removal responses. The responses showed that the oxidation of the planar compounds declined following the sequence DBT > 2-MB ≫ 4,6-DMDBT for all the MOFs. The findings revealed that at 66.7 °C, 3.0 equiv of oxidative agent over sulfur and 9.7 of MOF over sulfur by weight achieved the highest removal efficiency of 98.68% DBT, 93.23% 2-MB, and 69.32% 4,6-DMDBT for UiO-66-NO as a catalyst from the model fuel. It was also observed that UiO-66-NO had a higher efficiency in deep oxidative desulfurization when compared to other UiO-66-based catalysts used in the current study. Under optimal conditions, all the MOFs showed acceptable catalytic activity and reusability after four runs, although gradual loss of activity was observed.
本研究旨在测定具有不同官能团（-NO、-OH）的配体修饰的UiO-66在从模拟燃料（MF）中进行深度氧化脱硫时的催化活性和稳定性。平面硫化合物包括作为燃料相的正十二烷中的二苯并噻吩（DBT）、2-甲基苯并噻唑（2-MB）和4,6-二甲基二苯并噻吩（4,6-DMDBT）。通过X射线粉末衍射（XRD）、傅里叶变换红外光谱（FTIR）、质子核磁共振（H NMR）、扫描电子显微镜（SEM）、热重分析（TGA）、氮吸附-脱附分析以及微波等离子体原子发射光谱仪（MP-AES）对合成的功能化金属有机框架（MOF）样品进行了表征。采用中心复合设计方法进行实验评估和脱硫反应优化。运用响应面方法和方差分析来评估各个工艺因素、它们之间的相互作用以及脱硫响应。结果表明，对于所有的MOF，平面化合物的氧化活性按照DBT > 2-MB ≫ 4,6-DMDBT的顺序递减。研究结果显示，在66.7℃、氧化剂与硫的当量比为3.0以及MOF与硫的重量比为9.7的条件下，作为催化剂的UiO-66-NO从模拟燃料中对DBT的去除效率最高，达到98.68%，对2-MB的去除效率为93.23%，对4,6-DMDBT的去除效率为69.32%。还观察到，与本研究中使用的其他基于UiO-66的催化剂相比，UiO-66-NO在深度氧化脱硫方面具有更高的效率。在最佳条件下，所有的MOF在四次运行后均表现出可接受的催化活性和可重复使用性，尽管观察到活性逐渐降低。
