Wang Huixiang, Tang Mingxing, Shi Fenglei, Ding Ruimin, Wang Liancheng, Wu Jianbo, Li Xuekuan, Liu Zhong, Lv Baoliang
State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China.
Laboratory of Applied Catalysis and Green Chemical Engineering, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China.
ACS Appl Mater Interfaces. 2020 Aug 26;12(34):38140-38152. doi: 10.1021/acsami.0c10118. Epub 2020 Aug 12.
The oxidative desulfurization (ODS) of fuel oils is of great significance for environmental protection, and the development of efficient ODS heterogeneous catalysts is highly desired. Herein, we have designed and synthesized a novel material of amorphous CrWO-modified WO (a-CrWO/WO) nanowires (3-6 nm) with a large specific surface area of 289.5 m·g and rich Lewis acid sites. The formation of such a unique nanowire is attributed to the adsorption of Cr cations on non-(001) planes of WO. In the ODS process, the a-CrWO/WO nanowires can efficiently oxidize benzothiophene (BT), dibenzothiophene (DBT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) to their corresponding sulfones in a quasi-microemulsion reaction system and possess the highest activity ( = 55.4 kJ/mol) for DBT: 99.0% of 15,000 ppm DBT with 2600 ppm S can be removed (70 °C, HO as the oxidant). The improvement in ODS activity from most of WO catalysts is owing to the sufficient active sites and enhanced adsorption of DBT on the basis of structural features of a-CrWO/WO nanowires. Combined with free radical capture experiments, a possible ODS mechanism of W(O) peroxotungstate route based on surface -OH groups is reasonably proposed. Moreover, the a-CrWO/WO nanowires have good stability and can be synthesized on a large scale, suggesting its potential applications as an efficient heterogeneous catalyst.
燃料油的氧化脱硫（ODS）对环境保护具有重要意义，因此迫切需要开发高效的ODS多相催化剂。在此，我们设计并合成了一种新型材料——非晶态CrWO修饰的WO（a-CrWO/WO）纳米线（3-6纳米），其具有289.5 m²·g的大比表面积和丰富的路易斯酸位点。这种独特纳米线的形成归因于Cr阳离子在WO的非（001）面上的吸附。在ODS过程中，a-CrWO/WO纳米线能够在准微乳液反应体系中将苯并噻吩（BT）、二苯并噻吩（DBT）和4,6-二甲基二苯并噻吩（4,6-DMDBT）高效氧化为相应的砜，并且对DBT具有最高活性（Ea = 55.4 kJ/mol）：在70°C、以H2O2作为氧化剂的条件下，15000 ppm含2600 ppm硫的DBT中有99.0%能够被去除。与大多数WO催化剂相比，ODS活性的提高归因于a-CrWO/WO纳米线结构特征基础上充足的活性位点以及对DBT增强的吸附作用。结合自由基捕获实验，合理地提出了一种基于表面-OH基团的W（O）过氧钨酸盐途径的可能ODS机理。此外，a-CrWO/WO纳米线具有良好的稳定性并且能够大规模合成，表明其作为高效多相催化剂的潜在应用价值。
