A Facile Method for in Situ Preparation of the MnO₂/LaMnO₃ Catalyst for the Removal of Toluene

Abstract

MOx/ABO3 is a promising catalyst for the high-efficiency removal of volatile organic compounds. However, this catalyst is limited on practical applications due to its complex synthesis procedure and high cost. In this work, the MnO2/LaMnO3 catalyst was prepared in situ using a facile one-step method for the first time, in which partial La cations were selectively removed from three dimensionally chain-like ordered macroporous (3DOM) LaMnO3 material. After selective removal, the obtained MnO2/LaMnO3 sample expressed an excellent catalytic performance on toluene oxidation. Toluene could be completely oxidized into CO2 and H2O at 290 °C over the MnO2/LaMnO3 catalyst with a toluene/oxygen molar ratio of 1/100 and a space velocity of 120 000 mL/(g h). In addition, the apparent activation energy value of MnO2/LaMnO3 was 57 kJ/mol, which was lower than those of other metal oxides catalysts. According to O2-TPD and XPS results, it is concluded that the high catalytic performance of MnO2/LaMnO3 was mainly associated with the large amount of oxygen species and the excellent lattice oxygen mobility. MnO2/LaMnO3 is a promising catalyst for the practical removal of volatile organic compounds due to its high efficiency, good stability, low cost, and convenient preparation.

Improved CO Oxidation Activity of 3DOM Pr-Doped Ceria Catalysts: Something Other Than an Ordered Macroporous Structure

“…For instance, Ji et al [9] suggested that the improved catalytic activity of Co-and Febased 3DOM catalysts for toluene oxidation with regards to bulk catalysts could be related to the presence of a higher concentration of adsorbed oxygen species and better low-temperature reducibility, and the same argument has been used by Si et al [10] to explain the high toluene oxidation capacity of 3DOM MnO2/LaMnO3 catalysts. It is well known that the surface properties of pure and ceria-based mixed oxides play a key role in their catalytic performance.…”

Cobalt‐Doped Perovskite‐Type Oxide LaMnO3 as Bifunctional Oxygen Catalysts for Hybrid Lithium–Oxygen Batteries

“…[28,29] The perovskite LaMnO 3 indeed showso utstanding catalytic activity for the ORR, butp oor catalytic activityf or the OER. [28,29] The perovskite LaMnO 3 indeed showso utstanding catalytic activity for the ORR, butp oor catalytic activityf or the OER.…”

“…The oxideso ft he transition-metal manganese, such as MnO 2 and LaMnO 3 ,a re considered to be superior catalysts for the ORR. [28,29] The perovskite LaMnO 3 indeed showso utstanding catalytic activity for the ORR, butp oor catalytic activityf or the OER. For perovskite-type oxides of manganese,t he high activity is usually ascribed to the averagev alence of Mn 4 + /Mn 3 + , which provides am oderate interaction between the surfaceo ft he catalytic materiala nd intermediates.…”

Promotion of Oxygen Reduction with Both Amorphous and Crystalline MnOx through the Surface Engineering of La0.8Sr0.2MnO3‐δ Perovskite

“…The selective removal of A-site cations from the ABO 3 framework in acidic environments has been attributed to the longer length of the AÀO bonds in comparison to the BÀO bonds [40]. It is expected that if the ABO 3 perovskite is terminated with B-site elements, the catalytic activity will be improved [40][41][42][43][44]. The Sr removal and corresponding increased B-site cation coverage has been strongly correlated to the activity [40][41][42][43][44][45][46][47].…”

“…It is expected that if the ABO 3 perovskite is terminated with B-site elements, the catalytic activity will be improved [40][41][42][43][44]. The Sr removal and corresponding increased B-site cation coverage has been strongly correlated to the activity [40][41][42][43][44][45][46][47]. For example, Feng et al, used diluted HNO 3 to etch La and Sr away and promote the Mn-rich terminations, which in turn changed the Mn 4 + /Mn 3 + ratio and improve CO oxidation [41].…”