Numerous organometallic complexes of Mn, W, Co, Fe and V are used as catalysts for oxidation of a vast number of organic substrates including sulfides. However most of the catalysis is carried out in homogeneous media. The chief drawback of homogeneous catalysis is separation of the catalyst from reaction. Heterogeneous catalysts on other hand are easy to separate once reaction goes to completion. Solid supports such as alumina, silica, SBA-15 and MCM-41 are most commonly used to immobilize the catalysts. Our lab has invented acid prepared mesoporous silica (APMS) and it is our choice of support for heterogenization of catalysts. APMS is characterized by large surface area (upto 1500 m²/g), high pore volume and tunable pore size. We herein report two heterogeneous oxo vanadium complexes of pyridine-2,4,6-tricarboxylic acid (PYTCA) and 3-[N,N'-bis-3 (salicylidenamino) ethyltriamine] (Salten) which have been used to study the oxidation of 2-chloroethyl-ethylsulfide (CEES), a mustard gas analogue . The complexes are characterized using FTIR, EPR, N₂ physisorption and TGA analysis. The oxidation of CEES has been studied in solvents, such as 1-methyl-nonafluoro-butyl ether (HFE-7100), 2,2,2-trifluoroethanol (TFE), CH₃CN and CH₂Cl₂ using both homogeneous as well as immobilized catalysts in presence of TBHP as oxidant. Catalytic runs followed using GC-MS indicate that both catalyst systems selectively oxidize CEES to the partially oxidized sulfoxide with very little sulfone formation even at low loadings (1wt.%).