Low-Temperature Oxidation of Toluene over MnOx–CeO2 Nanorod Composites with High Sinter Resistance: Dual Effect of Synergistic Interaction on Hydrocarbon Adsorption and Oxygen Activation

Synergistic interaction derived by a heterointerface structure on the surface of metal oxide catalysts has a crucial role in improving the catalytic activity. In this work, MnOx nanoparticles were dispersed on the surface of CeO2 nanorods to generate a MnOx-CeO2 heterointerface structure, and its effect on toluene adsorption and catalytic oxidation performance was investigated. The results show that MnOx is well dispersed on CeO2 nanorods, and the interaction of Mn-Ce significantly reduces the strength of the Ce-O bond and increases the conversion of Ce4+ to Ce3+, which further promotes the activation of oxygen. Compared to MnOx on SiO2 without synergistic interaction, the enhancement of toluene adsorption on this novel MnOx-CeO2 hetero-interface structure can also make a great contribution to the improvement of the catalytic reaction process. Among them, the synergistic effect of CeO2-MnOx could reduce the temperature of 90% toluene conversion to 210 °C (this value is 83 °C lower than that over pure CeO2 nanorods). In addition, the fresh MnOx-CeO2 catalyst not only shows excellent stability and moisture resistance but also retains highly low-temperature activity even after thermal aging at 750 °C for 100 h.