Micellar effect: Evidence in favour of different mechanistic paths of chromium(VI) oxidation of formic acid and oxalic acid in aqueous acid media

Abstract

The cationic surfactant, cetylpyridinium chloride (CPC) inhibits the CrVI oxidation of formic acid in a monotoni fashion in aqueous U2SO4 media. On the other hand, under comparable conditions, CPC catalyses the CrVI oxidation of oxalic acid and then it inhibits the reaction after attaining a maximum value in the rate vs [CPC]T profile. The observed micellar effect has been explained in the light of the proposed reaction mechanism and it provides an indirect evidence in favour of 3e-transfer step for CrVI oxidation of oxalic acid.