Highly efficient oxidation of various thioethers with molecular oxygen catalyzed by bimetallic SnMo-MOF

Abstract

Bimetallic or polymetallic materials often exhibit different catalytic activities due to the interaction between different metal centers compared with monometallic materials. Here, we designed and synthesized a new bimetallic catalyst SnMo-MOF with tin and molybdenum as metal centers by solvothermal synthesis, which could realize the oxidation of diphenyl sulfide (Ph₂S) and difurfuryl sulfide (FFS) under mild conditions, and selectively generate sulfoxide and sulfone, respectively. The introduction of Sn enhanced the Lewis acidity of the catalyst surface and the electron transfer between Sn and Mo led to bimetallic synergistic catalysis, which made a great contribution to the high conversion and selectivity of sulfide oxidation. This is reflected in the complete conversion of Ph₂S and FFS with 91.8% and 98.1% selectivity of diphenyl sulfoxide (Ph₂SO) and difurfuryl sulfone (FFSO₂), respectively. The composite material had good substrate adaptability for the catalytic oxidation of other phenyl sulfides and furfuryl sulfides, which opens interesting prospects for the development of new MOF materials as efficient heterogeneous catalysts for the oxidation of thioethers.