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Alkali metal potassium was beneficial to the electronic regulation and structural stability of transition metal oxides. Herein, K ions were introduced into manganese oxides by different methods to improve the degradation efficiency of toluene. The results of activity experiments indicated that KMnO 4 -HT (HT: Hydrothermal method) exhibited outstanding low-temperature catalytic activity, and 90% conversion of toluene can be achieved at 243°C, which was 41°C and 43°C lower than that of KNO 3 -HT and Mn-HT, respectively. The largest specific surface area was observed on KMnO 4 -HT, facilitating the adsorption of toluene. The formation of cryptomelane structure over KMnO 4 -HT could contribute to higher content of Mn 3+ and lattice oxygen (O latt ), excellent low-temperature reducibility, and high oxygen mobility, which could increase the catalytic performance. Furthermore, two distinct degradation pathways were inferred. Pathway Ⅰ (KMnO 4 -HT): toluene → benzyl → benzoic acid → carbonate → CO 2 and H 2 O; Pathway ⅠⅠ (Mn-HT): toluene → benzyl alcohol → benzoic acid → phenol → maleic anhydride → CO 2 and H 2 O. Fewer intermediates were detected on KMnO 4 -HT, indicating its stronger oxidation capacity of toluene, which was originated from the doping of K + and the interaction between KOMn. More intermediates were observed on Mn-HT, which can be attributed to the weaker oxidation ability of pure Mn. The results indicated that the doping of K + can improve the catalytic oxidation capacity of toluene, resulting in promoted degradation of intermediates during the oxidation of toluene., Competing Interests: Declaration of Competing Interest There is no professional or other personal interest of any nature or kind in any product, service and/or company., (Copyright © 2023. Published by Elsevier B.V.)