A Comparison of Electron Donor and Proton Abstraction Activities of Thermally Activated Pure Magnesium Oxide and Doped Magnesium Oxides

Article abstract of DOI:10.1021/ja00238a020

Thermal activation of microcrystalline MgO at 400-700 deg C has been carried out under vacuum and under rapid flows of N2, Ar, O2, and H2/N2.Some samlpes of MgO were impregnated or coprecipitated with LiOH, NaOH, or Al(OH)3 before activation.The activities for 1-butene isomerization, where proton abstraction is limiting, were compared with activities for CO telomerization/reduction, where electron donation capability is most important.These studies suggest that defect sites are involved and that localized electron rich domains can be enhanced by Li⁺ substitution for Mg⁺ but that localized more electron difficient domains can be enhanced by Al³⁺ substitution for Mg²⁺.These studies also show that high-temperature thermal activation with gas flow of N2 or Ar is possible, but that O2 and H2/N2 anneal out defects and activity is lost.