In order to enhance the catalytic activity and improve the stability of Mn-Al oxides in acetone oxidation, it is interesting to have found that modulating and accelerating the rate-limiting step by Al substitution rather than just mixing of Mn and Al is crucial for hydrocarbon efficient catalytic destruction. Here, a series of Mn-Al oxides with different Al substitution ratios were prepared by a scalable and facile hydrothermal-redox strategy. The reaction rate, selectivity, and stability of the representative α-MnO 2 catalyst in acetone oxidation can be remarkably promoted by simple replacing of the partial framework Mn with Al, which changes the rate-limiting step from acetic acid dissociation to ethanol decomposition accelerated by H 2 O molecules. Among them, MnAl 0.5 displays the best catalytic performance with 90% of acetone converted at just 165 °C and a remarkable CO 2 yield. DFT results suggest that the p y and p x orbitals of the O element take part in the formation of the carbonyl group when the intermediate of removing H* from ethanol reacts with the hydroxyl group of H 2 O. The d xz orbital of Mn with p-electron of Al plays a vital role in the rate-limiting step. The work provides new insights into engineering catalysts for industrial VOC efficient and economical mineralization.