Estephane G, Lancelot C, Blanchard P, Toufaily J, Hamiye T, Lamonier C
Université Lille, CNRS, ENSCL, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et de Chimie du Solide F-59000 Lille France
MCEMA, Lebanese University, Faculty of Science, Rafic Hariri University Campus Hadath Lebanon.
RSC Adv. 2018 Apr 12;8(25):13714-13721. doi: 10.1039/c8ra01542b. eCollection 2018 Apr 11.
W based catalysts were synthesized by dry impregnation of SBA-15 mesoporous silica with phosphotungstic acid (HPW) solution with W contents between 5 and 20%, the HPW compound being preserved after calcination. The catalysts performance and the reactivity of various sulfide compounds were evaluated in the oxidative desulfurization (ODS) of model solutions and of real diesels, with sulfur contents ranging from 50 to 2000 ppm. The reactivity of benzothiophene and dibenzothiophene compounds was different in the ODS of model solutions but globally identical in the ODS of SRGO. The monitoring of the concentration of a range of alkyl DBT compounds (with alkyl groups from C2 to C5) in LGO confirmed the importance of the steric hindrance of alkyl substituents in the 4,6 position near the S atom, as well as of the size of the alkyl groups. Among the W/SBA series, the catalyst with the highest loading showed the best performance in the ODS of LGO and SRGO while the catalysts efficiency could not be discriminated in the ODS of model solutions. In the ODS of both model solutions and real feeds, the W/SBA catalyst was found to be much more efficient than a catalyst obtained by impregnation of a commercial silica with similar loading, highlighting the beneficial use of a mesoporous support with high surface area and pore volume that allowed well-dispersed tungsten species to be obtained. The quantity of sulfones precipitated and/or retained on the catalyst depended on the feed and was found to be higher in the ODS of model solution than in the ODS of real feeds. The precipitated/retained sulfones on the support may induce catalyst deactivation, which highlights the importance of the textural properties of the support. This detailed study points out the difficulty of extrapolating results obtained in the ODS of model solution to the ODS of real feeds.
通过用含钨量为5%至20%的磷钨酸（HPW）溶液对SBA - 15介孔二氧化硅进行干浸渍来合成W基催化剂，HPW化合物在煅烧后得以保留。在模型溶液和实际柴油的氧化脱硫（ODS）中评估了催化剂性能以及各种硫化物的反应活性，实际柴油的硫含量范围为50至2000 ppm。在模型溶液的ODS中，苯并噻吩和二苯并噻吩化合物的反应活性不同，但在SRGO的ODS中总体相同。对轻质瓦斯油（LGO）中一系列烷基二苯并噻吩化合物（烷基从C2到C5）浓度的监测证实了S原子附近4,6位烷基取代基的空间位阻以及烷基大小的重要性。在W/SBA系列中，负载量最高的催化剂在LGO和SRGO的ODS中表现出最佳性能，而在模型溶液的ODS中无法区分催化剂的效率。在模型溶液和实际进料的ODS中，发现W/SBA催化剂比用类似负载量浸渍商业二氧化硅得到的催化剂效率高得多，这突出了使用具有高表面积和孔体积的介孔载体的益处，这种载体能够获得分散良好的钨物种。沉淀和/或保留在催化剂上的砜的量取决于进料，并且发现在模型溶液的ODS中比在实际进料的ODS中更高。载体上沉淀/保留的砜可能会导致催化剂失活，这突出了载体结构性质的重要性。这项详细研究指出了将模型溶液ODS中获得的结果外推到实际进料ODS中的困难。
