【作者】 李娟；

【导师】 朱明远；

【作者基本信息】 石河子大学 ， 化学工程与技术， 2023， 硕士

【摘要】 化石燃油广泛应用于交通运输业。然而,含硫燃油燃烧后排放的有毒有害气体（SOx）对环境和人体有害。尽管世界各国对燃油中硫化物的排放含量严格控制在10百万分比浓度（ppm）以内,从燃料油中脱除硫化物才能从根本上解决问题。因此,化石燃料中硫化物的脱除技术成为新的研究方向。加氢脱硫技术（HDS）对于无机硫的脱除效果显著,但严苛的工艺条件（高温、高压）使其加工成本大幅增加。此外,HDS难以脱除噻吩（TH）类芳香硫化物,不符合深度脱硫的标准,非加氢脱硫技术应运而生。氧化脱硫（ODS）技术由于脱硫率高、反应设备操作简单、反应工艺条件温和等优势成为最具研究潜力的非加氢脱硫技术之一。本工作主要研究了应用于ODS反应中的金属有机骨架（MOF）和共价有机聚合物（COP）材料,以模型油为实验油品,以双氧水（H₂O₂）或氧气（O₂）为主要的氧化剂。研究结果表明,合成的材料脱硫效果显著,催化稳定性高。主要工作内容如下:（1）引入氨基（-NH₂）对锆（Zr）基金属有机骨架（UiO-66）进行官能团改性,得到UiO-66-NH₂催化剂。-NH₂的引入使UiO-66颗粒尺寸减小,材料的催化位点增多。将制备的催化剂应用于ODS反应中,在优化工艺条件后（T=60℃,t=180 min,O/S=4）,99.9%的二苯并噻吩（DBT）被除去,达到了深度脱硫的目的。催化剂表面的Lewis（L）酸位点(Zr⁴⁺)与-NH₂的协同作用是其保持较高活性的主要原因。然而,催化剂在循环使用7次后活性降低至82.5%,失活原因为催化剂团聚。（2）在Zr基金属有机骨架（MOF-808）中锚定过渡金属铜（Cu）,制备了Cu（Ⅰ）-MOF-808催化剂。Cu⁺的锚定不改变MOF-808的晶型结构和L酸含量。此外,Cu⁺促使H₂O₂产生羟基自由基（·OH）,·OH将DBT氧化为二苯并噻吩砜（DBTO₂）。在最佳反应条件下（T=60℃,t=120 min,O/S=8）,DBT的转化率达到99.9%。另外,Cu（Ⅰ）-MOF-808循环使用12次仍然保持99%以上的活性,通过表征分析发现其结构较MOF-808稳定,且反应过程中无活性位点流失。（3）合成具有三嗪结构的非金属共价有机聚合物材料（MC-TCOP）,采用O₂为氧化剂进行脱硫反应。三嗪结构中碳氮原子之间的电荷差异产生的能量吸附并活化O₂产生超氧自由基（·O₂^-）,·O₂^-将DBT氧化为DBTO₂。催化剂在最佳反应条件下（T=50℃,t=150 min,gas flow=90 m L/min）活性达到99.6%,循环实验表明材料重复使用9次后仍然能脱除95%以上的DBT。更多还原

【Abstract】 Fossil fuels are widely applied in transportation industry.However,toxic and hazardous gas（SOx）emitted by burning sulfurated fossil fuels are harmful to the environment and human body.Despite the emission of sulphides from fossil fuels is strictly controlled within 10 parts per million（ppm）in the worldwide,the desulfurization of fuel oil can fundamentally solve this problem.Therefore,technologies for removing of sulphides in fossil fuels have become a new research direction.Hydrodesulfurization（HDS）has remarkable effect on removing of inorganic sulphides.However,the processing cost increase greatly due to the high reaction temperature and pressure.Moreover,it is difficult for HDS to remove thiophene（TH）types of aromatic sulphides,which does not meet the standard of deep desulfurization,and further promotes the development of non-hydrodesulfurization technologies.Oxidative desulfurization（ODS）is one of the most potential non-hydrodesulfurization technologies profit from its high desulfurization rate,simple operation of reaction equipment and mild reaction conditions.Metal-organic framework（MOF）and covalent organic polymer（COP）materials that used in ODS reaction were investigated in this work,with model oil as the experimental oil,hydrogen peroxide（H₂O₂）or oxygen（O₂）as the main oxidant.The results manifested that the synthesized material exhibited remarkable ODS performance and catalytic stability.The main contents of work are as follows:（1）Zirconium（Zr）based metal-organic framework（UiO-66）was modified by introducing amino group（-NH₂）to obtain UiO-66-NH₂.The introduction of-NH₂ reduced the size of UiO-66 particles and increased the quantity of catalytic sites.The synthesized catalyst was applied into ODS reaction.After optimizing the process conditions（T=60℃,t=180 min,O/S=4）,99.9%of DBT could be removed,achieving the purpose of deep desulfurization.The synergistic effect between the Lewis（L）acid site(Zr⁴⁺)and-NH₂ on the catalyst surface is the main reason for its high activity.However,the catalyst performance decreased to 82.5%after7 times of recycling,the deactivation was caused by catalyst agglomeration.（2）Cu（Ⅰ）-MOF-808 catalyst was prepared through anchoring copper（Cu）in the Zr-MOF（MOF-808）.The anchoring of Cu⁺did not change the crystal structure and L acid content of MOF-808.In addition,Cu⁺promoted the generation of hydroxyl radical（·OH）from H₂O₂,which oxidized DBT to dibenzothiophene sulfone（DBTO₂）.Under the optimal reaction conditions（T=60℃,t=120 min,O/S=8）,the removal rate of DBT reached to 99.9%.In addition,the ODS activity of Cu（Ⅰ）-MOF-808 still maintained more than 99%after recycling for 12 times,its structure was more stable than MOF-808 and no active sites leaching during the reaction through characterization analysis.（3）Metal-free covalent organic polymer with triazine structure（MC-TCOP）was synthesized,and O₂was used as oxidant for desulfurization.The energy generated by charge difference between carbon and nitrogen atoms in triazine structure can adsorb and activate O₂ to produce superoxide radical（·O₂^-）,and·O₂^-oxidized DBT to be DBTO₂.Under the optimal reaction conditions（T=50℃,t=150 min,gas flow=90m L/min）,the catalyst performance reached to 99.6%,and the cyclic experiment showed that more than 95%of DBT was removed after 9 times of recycling.更多还原