Fig. 4: The CAT-like activity of MN_x.

a Reaction-time curves of the decomposition of H₂O₂ catalyzed by 4.8 μM MN_x (n = 3 independent experiments). ‘a. u.’ represents arbitrary units. b Quantification of specific CAT-like activities of MN_x. One enzyme activity unit represents the amount of MN_x that catalyzes the decomposition of 1 μmol H₂O₂ within 1 minute (n = 3 independent experiments; boxes represent the median and IQR and the upper and lower whiskers extending to the values that are within 1.5 × IQR). c Comparison of the stability of CAT-like activities between MN_x and natural enzymes (n = 3 independent experiments). d The energy barriers of MN_x in the CAT-mimic reaction simulated by DFT. e, f Schematic illustration of the cyclable catalytic CAT processes for MN_x. e Fe-Cu-N₆ and f Rh/VN₄. g The CAT processes with MN_x (Rh, V, and Fe-Cu). Dark gray, blue, red, cyan, light gray, orange, and brown balls represent H, C, N, O, Rh, V, Fe, and Cu atoms. The MN_x catalyst is represented by an asterisk (*) for clarity. e The energy barriers of MN_x in the CAT-mimic reaction simulated by DFT. All tests were performed at room temperature. All data are presented as mean ± SD. Some error bars are too small to be visible.