Vanadium catalyzed reduction of dioxygen to hydrogen peroxide: an oscillating process.

In acid isopropanol/water solution and aerobic conditions, (Bu)4N+VO3- in the presence of an initial amount of H2O2, catalyzes the autoxidation of isopropanol to acetone and the contextual dioxygen reduction to hydrogen peroxide, which accumulates in solution. We have observed that, in the system under examination, the build-up of H2O2 concentration shows an oscillatory behavior. Speciation of the peroxovanadium complexes in iPrOH/H2O has been explored with the combined use of 51V NMR, UV-Vis and ESI-MS techniques.