LAUSR

Through on the basis of density functional theory calculations (DFT), harmonic transition state theory and d-band center theory, the reaction mechanism and catalytic activity of Catalase, Superoxide dismutase and Peroxidase activities on the Co n Fe 3−n O 4 (n = 1–2) are systematically investigated. The results show that CoFe 2 O 4 is the most stable catalyst with the best catalytic effect. For the simulated activity of catalase, we find that the path-3 (H* and HO* → H 2 O) is the best on CoFe 2 O 4 and Co 2 FeO 4 . For the simulated activity of superoxide dismutase, the path HOO* + HOO → H 2 O 2  + O 2 is optimal on CoFe 2 O 4 and Co 2 FeO 4 . For the simulated activity of peroxidase, the mechanism on CoFe 2 O 4 and Co 2 FeO 4 is OOH* + H* → H 2 O + O*, O* + TMB → OH* + oxTMB, OH* + TMB → H 2 O + oxTMB. The results of these methods are consistent. The results thus provide an in-depth insight into the reaction mechanism and activity of Co n Fe 3−n O 4 as catalase, superoxide dismutase and peroxidase mimics and may play a role in the application of nanoparticles as mimics.