Controllable construction of Ce‐Mn‐O_x with tunable oxygen vacancies and active species for toluene catalytic combustion

Abstract

A series of Ce‐Mn‐Ox catalysts synthesized under different hydrothermal conditions were evaluated by catalytic removal of toluene. The results of characterization showed that the contents of oxygen vacancies and active species in catalysts were crucial for the catalytic oxidation process. The concentration of Ce3+, Mn3+, and adsorbed oxygen associated with structural defects in Ce‐Mn‐Ox catalysts could be controlled by hydrothermal conditions, which were considered to promote redox capacity and improve catalytic oxidation performance. In addition, suitable synthetic conditions could increase the SBET and Vp of catalysts. Among the prepared catalysts, CM‐100 showed the best catalytic performance due to the generation of more defective oxygen and active species (Ce3+, Mn3+, and surface‐adsorbed oxygen). In addition, the CM‐100 catalyst showed satisfactory water resistance and stability.

Efficient Degradation of Toluene over CeaMnβOX‐X Synthesized by One‐Step Strategy

“…Therefore, the experimental results were consistent with the literature [34] . Mn 3+ promoted the diffusion of oxygen and the generation of crystal defects, thereby enhancing the activity of the catalyst [31,65–67] …”

“…[34] Mn 3 + promoted the diffusion of oxygen and the generation of crystal defects, thereby enhancing the activity of the catalyst. [31,[65][66][67] Figure 6 (c) reflected the oxygen species on the surface of the catalyst, and it can be seen that the O 1s spectra were deconvoluted into two obvious peaks, with binding energies of 529.5-530.1 eV and 531-531.7 eV corresponding to lattice oxygen (O latt ) and adsorbed oxygen (O ads ), respectively. [68,69] According to the calculation and summary in Table 2, O ads /O latt changed according to the following: Ce 3 MnO X -10.5 (1.34) > CeMnO X -10.5 (0.63) > CeMn 2 O X -10.5 (0.56) > CeMnO X -8 (0.53) > CeMnO X -6 (0.46).…”

Comparison between hydrothermal and a facile sonochemical synthesis of Mn1‐XCeXOY, at different Ce loading, towards the catalytic oxidation of toluene

“…A clear peak located at 462 cm −1 increased its intensity as Ce content augmented. This signal corresponds to a symmetrical stretching vibration resulting from the atoms around Ce 4+ ions in the CeO 2 fluorite type structure [9,20,22] . The second signal at 642 cm −1 was assigned to the characteristic Mn−O stretching mode [9,20,22] .…”

Rational Design of Bimetal Mn-Ce Nanosheets Anchored on Porous Nano-sized ZSM-5 Zeolite for Adsorption-Enhanced Catalytic Oxidation of Toluene

“…Figure b shows the XPS spectra for O 1s. According to the peak-fitting deconvolutions, O 1s was divided into three characteristic peak segments at 529.8, 531.4, and 533 eV, which were attributed to the surface lattice oxygen (O latt ), adsorbed oxygen species (O ads ), and surface adsorbed hydroxyl species (O sur ), respectively. , The O 1s spectrum also showed that the adsorbed oxygen content increased gradually with increasing Ce content because of Ce doping, producing active oxygen species. Figure c shows the Mn 2p spectra of the different catalysts.…”