The study presented the preparation of the perovskite oxide LaNiO3 by the complex citrate method, paying particular attention to evolution of its formation from the amorphous precursor with varied calcination temperat...The study presented the preparation of the perovskite oxide LaNiO3 by the complex citrate method, paying particular attention to evolution of its formation from the amorphous precursor with varied calcination temperatures. The products obtained after heat treatment under air between 200 and 800 ℃ were characterized by X-ray diffraction （XRD）, thermogravimetric and differential thermal analysis （TG-DTA）, Fourier transform infrared spectroscopy （FTIR）, SBET measurements and X-ray photoelectron spectroscopy （XPS）. The results showed the formation of a single phase with perovskite structure from ca. 550 ℃. Tests on the two catalytic oxidation reactions of C3H6 and CO over the system calcined between mentioned temperatures were examined on the basis of characterization results and showed that optimum catalytic properties for such reactions were achieved for the perovskite calcined at 600 ℃. In turn, correlations between redox and catalytic properties were established on the basis of thermogravimetric temperature programmed reduction （TPR） analysis.展开更多
Three-dimensional ordered macroporous (3DOM) La1?xKxNiO3 perovskite-type catalysts were successfully prepared by a colloidal crystal template method and characterized by scanning electron microscopy, transmission elec...Three-dimensional ordered macroporous (3DOM) La1?xKxNiO3 perovskite-type catalysts were successfully prepared by a colloidal crystal template method and characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray scattering elemental mapping, X-ray diffraction, Raman and X-ray photoelectron spectroscopy, and temperature-programmed reduction of H2. Further, their catalytic activity in soot combustion was determined by temperature-programmed oxidation reaction. K substitution into the LaNiO3 lattice led to remarkably improved catalytic activity of this catalyst in soot combustion. Amongst various catalysts, La0.95K0.05NiO3 exhibited the highest activity in soot combustion (with its T50 and CO2 S values being 338 °C and 98.2%, respectively), which is comparable to the catalytic activities of Pt-based catalysts under the condition of poor contact between the soot and the catalyst. K-substitution improves the valence state of Ni and increases the number of oxygen vacancies, thereby leading to increased density of surface-active oxygen species. The active oxygen species play a vital role in catalyzing the elimination of soot. The perovskite-type La1?xKxNiO3 nanocatalysts with 3DOM structure without noble metals have potential for practical applications in the catalytic combustion of diesel soot particles.展开更多
基金Project supported by Comunidad de Madrid Project (DIVERCEL S2009/ENE-1475)
文摘The study presented the preparation of the perovskite oxide LaNiO3 by the complex citrate method, paying particular attention to evolution of its formation from the amorphous precursor with varied calcination temperatures. The products obtained after heat treatment under air between 200 and 800 ℃ were characterized by X-ray diffraction （XRD）, thermogravimetric and differential thermal analysis （TG-DTA）, Fourier transform infrared spectroscopy （FTIR）, SBET measurements and X-ray photoelectron spectroscopy （XPS）. The results showed the formation of a single phase with perovskite structure from ca. 550 ℃. Tests on the two catalytic oxidation reactions of C3H6 and CO over the system calcined between mentioned temperatures were examined on the basis of characterization results and showed that optimum catalytic properties for such reactions were achieved for the perovskite calcined at 600 ℃. In turn, correlations between redox and catalytic properties were established on the basis of thermogravimetric temperature programmed reduction （TPR） analysis.
基金supported by the National Natural Science Foundation of China(21673142)National Engineering Laboratory for Mobile Source Emission Control Technology(NELMS2017A05)+1 种基金PetroChina Innovation Foundation(2018D-5007-0505)Science Foundation of China University of Petroleum,Beijing(242017QNXZ02,2462018BJC005)~~
文摘Three-dimensional ordered macroporous (3DOM) La1?xKxNiO3 perovskite-type catalysts were successfully prepared by a colloidal crystal template method and characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray scattering elemental mapping, X-ray diffraction, Raman and X-ray photoelectron spectroscopy, and temperature-programmed reduction of H2. Further, their catalytic activity in soot combustion was determined by temperature-programmed oxidation reaction. K substitution into the LaNiO3 lattice led to remarkably improved catalytic activity of this catalyst in soot combustion. Amongst various catalysts, La0.95K0.05NiO3 exhibited the highest activity in soot combustion (with its T50 and CO2 S values being 338 °C and 98.2%, respectively), which is comparable to the catalytic activities of Pt-based catalysts under the condition of poor contact between the soot and the catalyst. K-substitution improves the valence state of Ni and increases the number of oxygen vacancies, thereby leading to increased density of surface-active oxygen species. The active oxygen species play a vital role in catalyzing the elimination of soot. The perovskite-type La1?xKxNiO3 nanocatalysts with 3DOM structure without noble metals have potential for practical applications in the catalytic combustion of diesel soot particles.
基金National Engineering Laboratory for Green Chemical Productions of Alcohols,Ethers and Esters and State Key Laboratory for Physical Chemistry of Solid Surface of Xiamen University
