Method for regenerating iron-loaded denox catalysts

A method for the regeneration of denox catalysts with an elevated SO2/SO3 conversion rate by the accumulation of iron compounds, comprising the steps of treating the denox catalyst with a substantially aqueous acidic solution with an addition of at least one antioxidant, wherein inorganic or organic acids are used as acid which are selected from the group consisting of H2SO4, HCl, H3PO4, HNO3, oxalic acid, citric acid, malonic acid, formic acid, chloroacetic acids, benzole sulfonic acid or mixtures of these acids, and wherein the at least one antioxidant is selected from the group consisting of substituted phenols, hydroquinones, catechols, and/or aliphatic, araliphatic or aromatic mercapto compounds, dithiocarbonates, hydroxycarboxylic acids, enediols and/or phosphites and phosphonates, including salts, esters and metal complexes, under such conditions that regeneration of the denox catalysts is effected.