In-Situ Formation of Layered La3Mn2O7 Induced by Use of a Chloride-Containing Intercalation Agent and Its Catalytic Performance for Toluene Oxidation

Compared with perovskite LaMnO₃, the R–P-type layered perovskite La₃Mn₂O₇ with a unique layered structure with large interlayer gap and weak Mn─O bond strength near the layered structure is beneficial to the dispersion of ions in the solvent and the intercalation of Cl⁻, which makes the material exhibit more development potential and research value in the catalytic oxidation of toluene. The effect of Cl⁻-type intercalation agent on the formation of layered structure and the catalytic oxidation of toluene was investigated. In the experiment, three kinds of Cl⁻-type intercalation agents, LaCl₃·7H₂O, NH₄Cl, and MnCl₂·4H₂O were selected to obtain three samples, which were labeled as LML, LMN, and LMM, respectively. The three samples are layered La₃Mn₂O₇, and the LMM material exhibits the best catalytic performance (T₉₀ = 269 °C) under the conditions of 18,000 mL/(g h) WHSV and 2000 mg/m³ toluene. LMM exhibits the largest specific surface area (26.88 m²/g), the best toluene adsorption performance and low temperature reduction performance (T = 344.2 °C), more acidic sites and oxygen species, which improves the activation ability of lattice oxygen and the fluidity of oxygen species. These characteristics make it an ideal structure for catalytic oxidation of toluene.