Expediting catalytic performance and water resistance of toluene decomposition over MnOx through alkali metal doping induced electronic modulation

Abstract

Achieving rapid ring–opening is considered the rate–limiting step in toluene oxidation, with water vapor having a positive effect on this objective. Herein, we propose a novel strategy for preparing K/MnOx catalyst by means of a secondary hydrothermal approach, capable of reducing the generation of intermediates and fosters a positive feedback loop in toluene oxidation by accelerating water dissociation. As indicated by characterizations, the presence of K not only effectively promotes the generation of reactive oxygen species and Mn3+ by expediting the electron transfer between Mn and O species but also act as a dopant to create more oxygen vacancies and therefore boosting the catalytic performance. Interestingly, despite competing adsorption of water molecules with toluene, the excellent water dissociation capability of K/MnOx creates a reactive oxygen species–rich surrounding. This environment facilitates ring cleavage stemming and ensures low–temperature oxidation of toluene simultaneously. The present study provides a new insight into the practical use of Mn–based catalysts for toluene decomposition.