A single-stage and dry catalytic process for the simultaneous removal of sulfur dioxide and nitrogen

The present invention provides catalysts for the simultaneous removal of SO2 and NOx from flue gases. The catalysts contain Ln-M-S-O compounds where Ln is selected from yttrium and rare earth metals and M is selected from Zr, Sr, V, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Pt are combinations thereof. The catalysts may be supported or unsupported, pretreated or untreated, but allow the simultaneous reduction of SO2 to S and NOx to N2. Elemental sulfur is a useful byproduct of the process.