Evaluation of crystalline structure and SO2 removal capacity of a series of MgAlFeCu mixed oxides as sulfur transfer catalysts

A series of MgAlFeCu mixed oxides with different Mg/Al atomic ratios derived from hydrotalcite-like compounds were prepared and tested for SO2 removal under the conditions similar to those of FCC units. The crystalline structures, the surface areas and the chemical compositions of the catalysts were investigated through the XRF, XRD, and N2 adsorption analysis. And spinel, spinel and Mg(Al)O, or Mg(Al)O was produced by changing the Mg/Al atomic ratios. The results of SO2 adsorption–reduction tests showed that the activities of the catalysts were strongly affected by the Mg/Al atomic ratio, structure and surface area. The sulfur transfer catalyst LDO6 (Mg/Al = 6) showed the excellent SO2 oxidative adsorption and reductive capacity, its total amounts of adsorbed SO2 reached 1.62 g SO2/g Cat, which was also remained at constant after eight cycles.