Abstract: The catalyst unit (1) for splitting a decontamination agent introduced into a containment for a decontamination process has at least one catalyst element (21). This catalyst element (21) first consists of a carrier material made of aluminum ceramics or activated carbon, and also of a catalytically active component in the form of nanoparticles, applied to the carrier material by means of chemical plating, and made of silver or silver oxide or of a silver and silver oxide mixture. The catalytically active component on the at least one catalyst element (21) is present in the range from 0.05 weight percent to 0.5 weight percent relative to the carrier material. The at least one catalyst element (21) has a catalytically effective surface in the range of up to 320 m2 per gram of used material, as a combination of carrier material plus applied catalytically active component. With the catalyst unit (1), an non-critical concentration of non-degraded decontamination agent of lower than 0.