Activation of Oxygen on MgO: O-2(center dot-) Radical Ion Formation on Thin, Metal-Supported MgO(001) Films

Distortion is the key: In situ EPR spectroscopy provides the first experimental confirmation that the adsorption of O2 molecules on a stoichiometric ultrathin MgO(001) film on Mo(001) leads to the spontaneous formation of O2.- radicals. The results show that polaronic distortion of the MgO lattice (see picture; Mg yellow, O blue) stabilizes the radical, and this distortion is only possible in very thin films. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.