Abstract Extractive-catalytic oxidative desulfurization (ECOD) technology is a potential industrial application for attaining low-sulfur fuel oils. In this research, novel graphene oxide (GO)-based heterogeneous catalysts were synthesized by immobilization of different amounts of phosphotungstic acid H3PW12O40 (HPW) on GO. The obtained HPW-GO catalysts were characterized by FT-IR, SEM, EDX, TEM, AFM, and RAMAN analyses. The ECOD was applied for removal of dibenzothiophene (DBT) from a model fuel with H2O2 as the oxidant, acetonitrile as the extracting solvent, and HPW-GOs as the catalysts. Among the catalysts with different HPW contents (5, 10, 20, 25, 30, 40 wt%), the catalyst with 40 wt% HPW had the best performance. The optimum reaction time, temperature, H2O2/sulfur molar ratio (O/S) as well as the kinetic parameters (kinetic constants and apparent activation energy) were evaluated. 100 percent desulfurization yield was achieved in a short time (t = 30 min) using the 40 wt% catalyst under moderate conditions (catalyst loading = 5 g/l, O/S = 6, T = 333 K). Aiding by synergism, the heterogeneous HPW-GO catalyst showed a higher desulfurization yield compared to that by the homogeneous HPW. The reactivity of 4,6-dimethyldibenzothiophene (4,6-DMDBT) in the ECOD process was found to be equal to that of DBT but much higher than the reactivity of benzothiophene (BT) within 60 min. The catalyst could be recycled for eight times without significant decrease in activity. A reasonable reaction pathway was proposed based on the GC–MS analysis. Almost all of the sulfur content of a real fuel could be completely oxidized and removed by the ECOD. Comparing to the results reported in literature, the features of proposed one-step fast ECOD process, which requires very low catalyst at moderate conditions for complete desulfurization without any phase transfer agent, makes it distinctive for practical applications.

中文翻译：

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使用氧化石墨烯基磷钨酸催化剂对燃料进行深度快速氧化脱硫

摘要 萃取-催化氧化脱硫（ECOD）技术是获得低硫燃料油的潜在工业应用。在这项研究中，通过将不同量的磷钨酸 H3PW12O40 (HPW) 固定在 GO 上，合成了新型氧化石墨烯 (GO) 基多相催化剂。获得的 HPW-GO 催化剂通过 FT-IR、SEM、EDX、TEM、AFM 和拉曼分析进行表征。以 H2O2 为氧化剂，乙腈为萃取溶剂，HPW-GOs 为催化剂，采用 ECOD 从模型燃料中去除二苯并噻吩 (DBT)。在不同HPW含量（5、10、20、25、30、40 wt%）的催化剂中，HPW含量为40 wt%的催化剂性能最好。最佳反应时间、温度、评估了 H2O2/硫摩尔比 (O/S) 以及动力学参数（动力学常数和表观活化能）。在中等条件下（催化剂负载量 = 5 g/l，O/S = 6，T = 333 K），使用 40 wt% 的催化剂在短时间内（t = 30 min）实现了 100% 的脱硫产率。通过协同作用，与均相 HPW 相比，非均相 HPW-GO 催化剂显示出更高的脱硫产率。发现 4,6-二甲基二苯并噻吩 (4,6-DMDBT) 在 ECOD 过程中的反应性与 DBT 的反应性相同，但远高于苯并噻吩 (BT) 在 60 分钟内的反应性。催化剂可以循环使用8次，活性没有明显下降。基于GC-MS分析提出了合理的反应途径。实际燃料中几乎所有的硫含量都可以被 ECOD 完全氧化和去除。与文献报道的结果相比，所提出的一步快速 ECOD 工艺的特点是，在没有任何相转移剂的情况下，在温和条件下需要非常低的催化剂来完全脱硫，使其在实际应用中与众不同。