La（0.6）Sr（0.4）Co（0.2）Fe（0.8）O（3-δ）（LSCF） anodes were infiltrated by Gd（0.2）Ce（0.8）O（1.9）GDC） nanoparticles to improve the oxygen evolution reaction（OER） performance of solid oxide electrolysis ce...La（0.6）Sr（0.4）Co（0.2）Fe（0.8）O（3-δ）（LSCF） anodes were infiltrated by Gd（0.2）Ce（0.8）O（1.9）GDC） nanoparticles to improve the oxygen evolution reaction（OER） performance of solid oxide electrolysis cells（SOECs） in CO2 electroreduction. The effect of GDC loading was investigated, and 10 wt% GDC nanoparticle infiltration of the LSCF（10 GDC/LSCF） anode results in the highest OER performance. Electrochemical impedance spectra measurements indicate that the infiltration by GDC nanoparticles greatly decreases the polarization resistance of the SOECs with the 10 GDC/LSCF anodes. The following distribution of relaxation time analysis suggests that four individual electrode processes are involved in the OER and that all of them are accelerated on the 10 GDC/LSCF anode. Three phase boundaries, surface oxygen vacancies, and bulk oxygen mobility increased, based on scanning electron microscopy and temperature-programmed desorption of O2 characterizations, and contributed to the enhancement of the four electrode processes of the OER and electrochemical performance of SOECs.展开更多
Ce0.8Sm0.2O1.9-δ-La0.9Sr0.1Ga0.8Mg0.2O3-δ（SDC-LSGM）is prepared by the glycine-nitrate process（GNP）.SDC-LSGM composite electrolyte samples with different weight ratios are prepared by the co-combustion method so ...Ce0.8Sm0.2O1.9-δ-La0.9Sr0.1Ga0.8Mg0.2O3-δ（SDC-LSGM）is prepared by the glycine-nitrate process（GNP）.SDC-LSGM composite electrolyte samples with different weight ratios are prepared by the co-combustion method so as to obtain homogeneous nano-sized precursor powders. The X-ray diffraction （XRD） and the scan electron microscope （SEM） are used to investigate the phases and microstructures. The measurements and analyses of oxygen ionic conductivity of SDC-LSGM are carried out through the four-terminal direct current （DC） method and the electrochemical impendence spectroscopy, respectively. The optimum weight ratio of SDC-LSGM is 8∶2, of which the ionic conductivity is 0.113 S/cm at 800℃ and the conductivity activation energy is 0.620 eV. The impendence spectra shows that the grain boundary resistance becomes the main barrier for the ionic conductivity of electrolyte at lower temperatures. The appropriate introduction of LSGM to the electrolyte SDC can not only decrease the electronic conductivity but also improve the conditions of the grain and grain boundary, which is advantageous to cause an increase in oxygen ionic conductivity.展开更多
基金This work was supported by the National Key R&D Program of China(2017YFA0700102)the National Natural Science Foundation of China(21703237,21573222,91545202)+1 种基金Dalian Institute of Chemical Physics(DICP DMTO201702)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020200)and CAS Youth Innovation Promotion(2015145)~~
文摘La（0.6）Sr（0.4）Co（0.2）Fe（0.8）O（3-δ）（LSCF） anodes were infiltrated by Gd（0.2）Ce（0.8）O（1.9）GDC） nanoparticles to improve the oxygen evolution reaction（OER） performance of solid oxide electrolysis cells（SOECs） in CO2 electroreduction. The effect of GDC loading was investigated, and 10 wt% GDC nanoparticle infiltration of the LSCF（10 GDC/LSCF） anode results in the highest OER performance. Electrochemical impedance spectra measurements indicate that the infiltration by GDC nanoparticles greatly decreases the polarization resistance of the SOECs with the 10 GDC/LSCF anodes. The following distribution of relaxation time analysis suggests that four individual electrode processes are involved in the OER and that all of them are accelerated on the 10 GDC/LSCF anode. Three phase boundaries, surface oxygen vacancies, and bulk oxygen mobility increased, based on scanning electron microscopy and temperature-programmed desorption of O2 characterizations, and contributed to the enhancement of the four electrode processes of the OER and electrochemical performance of SOECs.
基金The National Basic Research Program of China (973 Program) (No.2007CB936300)the Natural Science Foundation of Jiangsu Province (No.BK2009293)
文摘Ce0.8Sm0.2O1.9-δ-La0.9Sr0.1Ga0.8Mg0.2O3-δ（SDC-LSGM）is prepared by the glycine-nitrate process（GNP）.SDC-LSGM composite electrolyte samples with different weight ratios are prepared by the co-combustion method so as to obtain homogeneous nano-sized precursor powders. The X-ray diffraction （XRD） and the scan electron microscope （SEM） are used to investigate the phases and microstructures. The measurements and analyses of oxygen ionic conductivity of SDC-LSGM are carried out through the four-terminal direct current （DC） method and the electrochemical impendence spectroscopy, respectively. The optimum weight ratio of SDC-LSGM is 8∶2, of which the ionic conductivity is 0.113 S/cm at 800℃ and the conductivity activation energy is 0.620 eV. The impendence spectra shows that the grain boundary resistance becomes the main barrier for the ionic conductivity of electrolyte at lower temperatures. The appropriate introduction of LSGM to the electrolyte SDC can not only decrease the electronic conductivity but also improve the conditions of the grain and grain boundary, which is advantageous to cause an increase in oxygen ionic conductivity.
