La2O3-CeO2 samples were prepared by combustion synthesis with 3.66wt% Ni, synthetically represented as Ce0.70La0.20N0.10O2-d, [1]. In the present work the influence of the reduction temperature on the structural characteristics in catalytic samples of Ce0.70La0.20N0.10O2-d (Ni=3.66 wt%), in the range between 450 and 900°C, during methane dry reforming reaction to synthesis gas has been studied, by using High Resolution Transmission Electron Microscopy (HRTEM) Scanning Transmission Electron Microscopy-Energy dispersive spectroscopy- Electron Energy Loss Spectroscopy (STEM-EDS-EELS). Selected Area Electron Diffraction patterns (SAED) have shown first the co-existence of the cubic phase of CeO2, the cubic phase and a new phase most probably a ternary phase of Ce1-xLaxO2. Moreover, we evaluated, redox and catalytic properties of those Ce0.70La0.20N0.10O2-d, catalysts after the H2/N2 treatment at three different temperatures, 450°C, 750°C and 900°C, aiming to study the influence of this properties on the catalyst activity and stability [2]. There is no evidence of the presence of the La2O3 phase. However, a new phase Ce1-xLaxO2 has been detected and analyzed through STEM-EDS analysis at the nanometer scale. Further investigation has to confirm, if the correlation, between the Cerium and Lanthanum in the average atomic ratio (%) 0.7 to 0.2 respectively, remains the same or not. Additionally STEM-EELS analysis shows a variation in the proportion of the oxidation state of Ce3+ and Ce4+, as the temperature increases to 900°C.
Influence study of the reduction temperature on the structural characteristics in Ce070La0.20Ni0.10O2-d by HRTEM/STEM-EELS
C Italiano;L Pino
2018
Abstract
La2O3-CeO2 samples were prepared by combustion synthesis with 3.66wt% Ni, synthetically represented as Ce0.70La0.20N0.10O2-d, [1]. In the present work the influence of the reduction temperature on the structural characteristics in catalytic samples of Ce0.70La0.20N0.10O2-d (Ni=3.66 wt%), in the range between 450 and 900°C, during methane dry reforming reaction to synthesis gas has been studied, by using High Resolution Transmission Electron Microscopy (HRTEM) Scanning Transmission Electron Microscopy-Energy dispersive spectroscopy- Electron Energy Loss Spectroscopy (STEM-EDS-EELS). Selected Area Electron Diffraction patterns (SAED) have shown first the co-existence of the cubic phase of CeO2, the cubic phase and a new phase most probably a ternary phase of Ce1-xLaxO2. Moreover, we evaluated, redox and catalytic properties of those Ce0.70La0.20N0.10O2-d, catalysts after the H2/N2 treatment at three different temperatures, 450°C, 750°C and 900°C, aiming to study the influence of this properties on the catalyst activity and stability [2]. There is no evidence of the presence of the La2O3 phase. However, a new phase Ce1-xLaxO2 has been detected and analyzed through STEM-EDS analysis at the nanometer scale. Further investigation has to confirm, if the correlation, between the Cerium and Lanthanum in the average atomic ratio (%) 0.7 to 0.2 respectively, remains the same or not. Additionally STEM-EELS analysis shows a variation in the proportion of the oxidation state of Ce3+ and Ce4+, as the temperature increases to 900°C.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
