Molybdenum Dioxide Nanoparticles Anchored on Nitrogen‐Doped Carbon Nanotubes as Oxidative Desulfurization Catalysts: Role of Electron Transfer in Activity and Reusability

Abstract

AbstractElectron transfer between metal‐oxides and supports considerably affects the oxidative desulfurization (ODS) performance of catalysts, while this is far from being well understood. Herein, molybdenum dioxide with oxygen vacancies (VO‐MoO2) catalysts derived from Mo‐based metal‐organic frameworks are anchored on electron‐rich nitrogen‐doped carbon nanotubes (NC) to obtain excellent ODS activity and reusability. Results show that either dibenzothiophene (DBT) or 4,6‐dimethyldibenzothiophene (4,6‐DMDBT) is removed 100% on the composite catalyst (VO‐MoO2@NC) within 40 min of reaction when cumene hydroperoxide is chosen as an oxidant. After five cycles of reaction, DBT and 4,6‐DMDBT removal still exceeded 99.5 and 95.0%, respectively. Results from density functional theory calculations and characterizations confirm that the strong electron‐donating effect of NC on VO‐MoO2 can promote the dispersion of VO‐MoO2 and reduce the bond energy of the MoO bond, leading to exposure of active sites and enrichment of oxygen vacancies (VO). Furthermore, the strong interfacial electrostatic interaction caused by the electron transfer from NC to VO‐MoO2 can reduce the leaching of active sites of the catalyst. This study provides a versatile strategy of constructing strong electronic interaction between metal‐oxide and support via anchoring on NC for the design of high‐performance ODS catalysts.