Mesoporous double-perovskite LaAMnNiO₆ (A = La, Pr, Sm) photothermal synergistic degradation of gaseous toluene

A series of double-perovskite LaAMnNiO6(A = La, Pr, Sm) catalysts with mesoporous morphology was prepared by a sol–gel method and further applied into photothermal synergistic degradation of gaseous toluene. Transmission electron microscopy and Brunauer–Emmett–Teller characterizations confirmed that double-perovskite LaAMnNiO6(A = La, Pr, Sm) had obvious mesoporous structure, which can provide a larger specific surface area and further enhancing the reactivity of catalyst. UV-vis and X-ray photoelectron spectroscopy characterization illustrated that LaSmMnNiO6possessed higher adsorption oxygen content and light absorption capacity, which contribute to the occurrence of catalytic oxidation in the Mars–van Krevelen redox cycle mechanism. A group of active tests showed that the double-perovskite LaSmMnNiO6catalyst had a lower reaction initiation temperature (starting reaction at 75 °C) and a lower activity temperature of optimal reaction (more than 90% at 255 °C). Moreover, the research on reaction kinetics of the catalyst demonstrated that LaAMnNiO6(A = La, Pr, Sm) had lower activation energy and thus exhibited better catalytic activity. The results of the study indicate that the double-perovskite LaAMnNiO6(A = La, Pr, Sm) has broad application prospects in the field of volatile organic pollutant degradation.