Mg,Mn,Al-oxides with spinel structure, Al/(M 2+ +Al) molar ratio of 0.25 and 0.50 and an Mn/Mg molar ratio of 0.30 have been evaluated as catalysts for SO x removal under conditions similar to those found in FCC units. The best performance was that of the sample with the higher aluminium content. The incorporation of CeO 2 in this sample favored SO x uptake for short reaction times as well as the reduction of the sulfated catalysts. When the regeneration was started at 530°C, only H 2 S was observed as reaction product, but when this step started at 650°C, the release of SO 2 preceded that of H 2 S, regardless of the chemical composition of the sample. As to the additive performance for successive reaction–regeneration cycles, the incorporation of CeO 2 produced a less efficient catalyst with regard to the removal of the SO 2 along the process, but with a higher regeneration efficiency and a lower formation of SO 2 as regeneration product.