Enhanced Catalytic Combustion Performance of Toluene over a Novel Co–CeOx Monolith Catalyst

To improve the catalytic combustion performance of toluene, a series of Co–CeOx monolith catalysts were synthesized by the citric acid sol–gel method. The results showed that the introduction of Co to CeO2 by the citric acid sol–gel method can effectively improve the catalytic performance in the reaction of toluene oxidation. Co1Ce2Ox with the molar ratio of Co to Ce being 1:2 showed optimal activity and reached T90 at 275 °C. In addition, Co1Ce2Ox exhibited excellent adaptability under the various space velocities and concentration conditions, and it also revealed good thermal stability. The physical and chemical properties of the as-prepared catalysts were investigated by various technologies. The results showed that the combination of Co and Ce could induce a strong interaction between Co3O4 nanoparticles and CeO2 nanoparticles, exerting a synergistic promoting effect on the formation of oxygen vacancies, which subsequently enhances the active oxygen mobility and improves the catalytic oxidation performance. The possible mechanism of enhanced catalytic performance of Co1Ce2Ox was also proposed.