Enhanced catalytic oxidative desulfurization performance via facile synthesis of a MoO2/BCN nanocomposite under solventless and mild reaction conditions

Abstract

Exploring heterogeneous catalysts with superior catalytic capability and remarkable durability for deep desulfurization of stubborn sulfides is of great significance. In this regard, molybdenum-based ionic liquid, boric acid, and urea are introduced to fabricate a MoO₂/BCN nanocomposite to achieve a superior sulfur elimination performance. Here, 100% dibenzothiophene (DBT) removal is achieved within 40 min under the optimized reaction conditions. Additionally, effective sulfur elimination could also be achieved for other refractory sulfides. Electron transfer from the BCN carrier to active MoO₂ sites is observed in the obtained catalyst, preventing the leaching of active sites and facilitating the catalytic activity effectively. Thus, 98.2% removal of DBT is still realized following 9 cycle runs. Here, the constructed MoO₂/BCN acts as both an adsorbent and a catalyst. The DBT in the oil phase is first adsorbed by the BCN carrier, resulting in a higher sulfur concentration on the catalyst surface. Then, it is oxidized to its corresponding sulfone by the produced hydroxyl radical. The generated insoluble sulfone precipitates and aggregates along with the catalyst phase, realizing efficient desulfurization from the oil phase. The simple construction of the MoO₂/BCN nanocomposite with remarkable sulfur removal efficiency and durability illustrates a feasible pathway to construct similar heterogeneous catalysts with remarkable catalytic capability.