Weakened Mn–O bond in Mn–Ce catalysts through K doping induced oxygen activation for boosting benzene oxidation at low temperatures

K-doped Mn–Ce solid solution catalysts were synthesized using a combination of coprecipitation and hydrothermal methods, demonstrating excellent performance in benzene oxidation. The catalyst K 1 Ce 5 Mn 5 exhibited comparable activity to noble metal catalysts, achieving a 90 % benzene conversion at approximately 194 ℃. Durable tests under dry and moist conditions revealed that the catalyst could maintain its activity for 50 h at 218 ℃ and 236 ℃, respectively. Characterization results indicated that the catalyst’s enhanced activity resulted from the weakened Mn–O bonding caused by the introduction of K + , facilitating the activation of oxygen and its involvement in the reaction. CeO x , the main crystalline phase of Mn–Ce solid solutions, provided abundant oxygen vacancies for capturing and activating oxygen molecules for the weakened Mn–O structures. This conclusion was further supported by partial density of state analysis from density functional theory computations, revealing that the introduction of K + weakened the orbital hybridization of Mn3d and O2p. Finally, in situ diffuse reflectance infrared Fourier-transform spectroscopy ( in situ DRIFTS) studies on Ce 5 Mn 5 and K 1 Ce 5 Mn 5 catalysts suggested that the introduction of K + promoted the conversion of adsorbed benzene. Furthermore, intermediate products were transformed more rapidly for K 1 Ce 5 Mn 5 compared to Ce 5 Mn 5 .