Catalase  in general could catalyzed two type of reaction 1-Decomposition of H2O2

Catalase disproportionates:

2H2O2 to 2H2O + O2,

2- A second family of reactions catalyzed by Catalase, possibilities for the compound RH2 include phenols, formic acid, formaldehyde and alcohols:

H2O2 + RH2 to 2H2O + R,

Both reactions catalysed by Catalase, hydrogen peroxide disproportionation and the peroxidative reaction consume H2O2

good luck

Dear Ran

1)      The only relevant reference I have read about your first question is “Together with APX, catalases are also distinguished from many other peroxide-metabolizing

enzymes by their high specificity for H2O2, but weak activity against organic peroxides” in Mhamdi et al., 2010, Catalase function in plants: a focus on Arabidopsis mutants as stress-mimic models, Journal of Experimental Botany, 61:4197-4220.

2)      Concerning to your second question, Halliwell and Gutteridge (Free radicals in biology and medicine, 3rd edition, 1999, Oxford University Press, p. 138) refer about the peroxidatic activity of catalase:

“Mammalian catalases can also catalyse certain peroxidase-type reactions, restricted by accessibility of substrates to the haem. Compound I will oxidize the alcohols methanol and ethanol to their corresponding aldehydes… but propanols or butanols are much poorer substrates. Formic acid can be oxidized to CO2 by the peroxidase action of compound I.”