Nanoscale Metal Oxide Particles as Chemical Reagents. Heats of Adsorption ofHeteroatom-Containing Organics on Heat-Treated Magnesium Oxide Samples of Varying Surface Areas

摘要

We have been investigating the preparation and surface activation of high surfacemetal oxides and consider them as potential reagents for absorbing and destroying heteroatom containing organic compounds. Recently we have been able to extend our studies to ultrahigh surface area (nanoscale particles) materials. The potential of ionic metal oxides as destructive adsorbents should depend on surface area. The higher the surface area the more reactive surface defects (coordinatively unsaturated ions, cation or anion vacancies) should be available, and so adsorptive capacity and surface reactivity (affinity) should increase. Indeed, this should be manifestation of the unusual chemical properties of nanoscale ionic particles. To obtain more quantitative information about these strong chemisorption processes, we have prepared a series of MgO samples of varying surface area and have measured heat of adsorption of a wide variety of organic compounds. An immediate goal has been to elucidate the mode of these surface interactions. A long range goal, however, is to develop these oxide reagents for use in air purification.