Roles of Oxygen Vacancies of CeO2 and Mn-Doped CeO2 with the Same Morphology in Benzene Catalytic Oxidation

Abstract

Mn-doped CeO2 and CeO2 with the same morphology (nanofiber and nanocube) have been synthesized through hydrothermal method. When applied to benzene oxidation, the catalytic performance of Mn-doped CeO2 is better than that of CeO2, due to the difference of the concentration of O vacancy. Compared to CeO2 with the same morphology, more oxygen vacancies were generated on the surface of Mn-doped CeO2, due to the replacement of Ce ion with Mn ion. The lattice replacement has been analyzed through XRD, Raman, electron energy loss spectroscopy and electron paramagnetic resonance technology. The formation energies of oxygen vacancy on the different exposed crystal planes such as (110) and (100) for Mn-doped CeO2 were calculated by the density functional theory (DFT). The results show that the oxygen vacancy is easier to be formed on the (110) plane. Other factors influencing catalytic behavior have also been investigated, indicating that the surface oxygen vacancy plays a crucial role in catalytic reaction.

Mechanistic Insight into the Promotion of the Low-Temperature NH3-Selective Catalytic Reduction Activity over MnxCe1–xOy Catalysts: A Combined Experimental and Density Functional Theory Study

“…The intensities of the EPR signals of · O 2 – follow the order Mn/Ce = 0.4 > Mn/Ce = 0.1 > CeO 2 (Figure ). This result is consistent with the analysis of the visible Raman spectra (see the D-band change in Figure S5) and XPS data showing that a higher doping ratio means more oxygen vacancies and thus more reactive · O 2 – species …”

Photocatalytic C–N coupling towards urea synthesis with a palladium-supported CeO2 catalyst

“…2d and S4d † display the O 1s XPS spectra, in which the peaks at 529.2 eV, 531.2 eV and 533.0 eV were assigned to the lattice oxygen, surface adsorbed oxygen and hydroxyl oxygen, respectively. 40 Besides, the slight shift towards a higher binding energy for the O 1s XPS spectra was observed (Table S5 †), which could be resulted from the doped Pd owing to its higher electronegativity. 41 Consequently, the above results convincingly indicated the successful fabrication of Pd-CeO 2 .…”

Syngas production at a near-unity H2/CO ratio from photo-thermo-chemical dry reforming of methane on a Pt decorated Al2O3–CeO2catalyst

“…The peak at $532.0 eV was identied as adsorbed oxygen (O A ) on oxygen vacancies, which can be applied to determine the concentration of surface vacancies. 50,51,54 Based on the O 1s deconvolution result shown in Fig. 4, the O A concentrations on Pt-Ce and Pt-Al-Ce were calculated to be 27.0% and 15.5%, respectively.…”