Boosting the Catalytic Performance of Volatile Organic Compound Oxidation Over Platelike MnO2/CoAlO Catalyst by Weakening the Co–O Bond and Accelerating Oxygen Activation

Sample morphology is known to have a significant influence on catalytic performance due to changes in catalysts' crucial properties such as active sites, oxygen vacancies, and active oxygen species. It is worthwhile revealing the differences in catalyst properties and reaction mechanisms for modified catalysts with different morphologies. Herein, MnO2 was grown in situ on platelike CoAlO (denoted as CoAlO-P) and flowerlike CoAlO (denoted as CoAlO-F) for high-efficiency oxidation of volatile organic compounds, in which platelike MnO2/CoAlO-P exhibited a low T90% of 175 °C, good stability, and water resistance. Experimental and theoretical results revealed that in comparison with CoAlO-F, MnO2 modification of platelike CoAlO-P led to predominant exposure of Co species and weak Co–O bond due to the strong interaction between CoAlO-P and MnO4–, which promoted the adsorption/activation of acetone. The oxygen vacancy generated from breaking a Co–O bond adjacent to Mn on MnO2/CoAlO-P was shown to have a strong capacity to dissociate O2 into active oxygen species, accelerating the conversion of formate, acetate, and aldehyde intermediate species into CO2 and H2O. This investigation will guide the rational design of catalysts for application in hydrocarbon oxidation reactions.