Reactivity of low-coordination sites on the surface of magnesium oxide

Abstract

Photoluminescent and electron spin resonance studies of MgO smoke powders show that etching of the smoke cubes by water vapour leads to an increase in the number of reactive sites of low coordination on the surface without a parallel increase in the surface area. The formation of anion radicals after adsorption of oxygen and nitrobenzene was used as a monitor of the number of sites of low coordination and it is suggested that 3-coordinated surface O^2– ions are involved in the formation of radical ions from both adsorbates.