Subject: Soluble catalyst that decompose H2O2

I was doing an experiment at home with copper(II) sulphate and 
sodium chloride .
I added Hydrogen peroxide to the mixture. The reaction was rather 
exothermic and vigorous . After rection stopped , i filtered and 
evaporated the mixture to form crystals . it can decomposed H2O2 
just as vigotously . I wonder if there is something to do with 
ion-exchange in terms of a catalyst ?
as the concentration of the solution drops , the reaction slows 
down as well
can anyone out there help me explain this phenomemum ?

Re: Soluble catalyst that decompose H2O2