Graphene-like boron nitride anchored Bronsted acid ionic liquids as metal-free catalyst for advanced oxidation process

Catalytic oxidation of aromatic sulfur compounds for separation from fuel oils has turned to be an important theme in environmental protection. However, most current reports focused on metal-based catalysts, resulting in high costs and potential secondary pollution to fuel oils. In this work, three metal-free bronsted acid ionic liquids were prepared and anchored onto graphene-like hexagonal boron nitride (G-h-BN) to gain metal-free, heterogeneous catalysts. The heterogenization process not only provided convenience to recycling of the catalysts, but also supplied a sharply decreased ILs dosage. Notably, the prepared catalyst [Bmim]H2PO4/G-h-BN held the best catalytic activity, a 100% of catalytic activity can be gained in catalytic oxidation of 4,6-dimethyldibenzothiophene (4,6-DMDBT), which has been regarded as the most stubborn sulfide in industrial hydrodesulfurization (HDS). It was also found that distractors in fuels showed almost no influence on catalytic oxidation of 4,6-DMDBT. Besides, the catalytic oxidation product was also investigated to propose a possible reaction mechanism. The heterogeneous metal-free catalyst were recycled for 5 times without significant decrease in catalytic performance. (C) 2017 Elsevier B.V. All rights reserved.