Selective Sulfur Dioxide Adsorbents Prepared from Designed Dispersions of Groups IA and IIA Metal Oxides on Alumina

Abstract

Supported M(I)/alumina and M(II)/alumina adsorbents were prepared using Mn+(acac)nas the precursor. These materials may be decomposed by careful heating to create dispersions of Mn+On/2/alumina which are SO2adsorbents. These adsorbents have been characterized by elemental analyses, diffuse reflectance infrared Fourier transform analysis spectroscopy, SO2adsorption capacity, and powder X-ray diffraction. The MgO/alumina prepared from Mg(acac)2·2H2O shows high dispersion of Mg species which are stable against sintering even when calcined to 500°C. The incremental SO2sorption capacity of this material shows nearly 1 mol SO2/mol Mg2+in the sample. The sample prepared from Li(acac) shows more SO2adsorption than the MgO/alumina for loadings <150 μmol/g alumina. However, the LiO/alumina samples show low incremental adsorption of SO2per mol of Li ion (0.12 mol/mol) at metal loadings greater than 150 μmol/g alumina. These results are discussed in the framework of ensemble theory in the light of the solution chemistry of the metal acetylacetonates.