摘要: Ionic, insulator oxides can be prepared in high surface area forms resulting in a relatively high proportion of surface/bulk metal oxide moieties. Such microcrystalline particles can possess a wide variety of defect sites includin... 展开 Ionic, insulator oxides can be prepared in high surface area forms resulting in a relatively high proportion of surface/bulk metal oxide moieties. Such microcrystalline particles can possess a wide variety of defect sites including structural (kinks, steps, cleavage planes, cation, and anion vacancies), and electronic (electron excess/deficient centers). In addition, surface impurities, especially adsorbed H2O, OH, and H, can have important effects. Such defects play an important role in the rich surface chemistry of metal oxides. However, progress toward learning what defects are responsible for specific surface reactions has been very slow. The complexity of the surface structure has hampered real progress. One serious problem is that is has been difficult to distinguish diamagnetic from paramagnetic defects since ESR detection of some paramagnetic sites has been very difficult due to relaxation times. Keywords: Magnesium oxide, Thermal activation, Spin traps, Nitrones, Nitroso, Electron transfer, Cation vacancies, Anion vacancies, Electron spin resonance, Surface adsorption. (JES) 收起