The present invention relates to a catalyst comprising at least one catalytically active metal selected from elements in Groups 7 to 11, wherein the catalytically active metal is supported on a support material being grafted with acid groups other than OH groups and wherein the catalytically active metal is different from the metal of the support material. 1% to 70% of the metal is present in reduced form. The preferred catalytically active metal is palladium. The invention further relates to a method for preparing said catalyst and the use of said catalyst for catalyzing reactions, in particular the direct synthesis of hydrogen peroxide.