Solid oxide electrolysis cells(SOECs),displaying high current density and energy efficiency,have been proven to be an effective technique to electrochemically reduce CO_(2)into CO.However,the insufficiency of cathode ...Solid oxide electrolysis cells(SOECs),displaying high current density and energy efficiency,have been proven to be an effective technique to electrochemically reduce CO_(2)into CO.However,the insufficiency of cathode activity and stability is a tricky problem to be addressed for SOECs.Hence,it is urgent to develop suitable cathode materials with excellent catalytic activity and stability for further practical application of SOECs.Herein,a reduced perovskite oxide,Pr_(0.35)Sr_(0.6)Fe_(0.7)Cu_(0.2)Mo_(0.1)O_(3-δ)(PSFCM0.35),is developed as SOECs cathode to electrolyze CO_(2).After reduction in 10%H_(2)/Ar,Cu and Fe nanoparticles are exsolved from the PSFCM0.35 lattice,resulting in a phase transformation from cubic perovskite to Ruddlesden-Popper(RP)perovskite with more oxygen vacancies.The exsolved metal nanoparticles are tightly attached to the perovskite substrate and afford more active sites to accelerate CO_(2)adsorption and dissociation on the cathode surface.The significantly strengthened CO_(2)adsorption capacity obtained after reduction is demonstrated by in situ Fourier transform-infrared(FT-IR)spectra.Symmetric cells with the reduced PSFCM0.35(R-PSFCM0.35)electrode exhibit a low polarization resistance of 0.43Ωcm^(2)at 850℃.Single electrolysis cells with the R-PSFCM0.35 cathode display an outstanding current density of 2947 mA cm^(-2)at 850℃and 1.6 V.In addition,the catalytic stability of the R-PSFCM0.35 cathode is also proved by operating at 800℃with an applied constant current density of 600 mA cm^(-2)for 100 h.展开更多
This work demonstrates that in situ formation of carbonate layer on the surface of Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF)obtained by exposure to CO2 during heating between 500℃ and 700℃ can provide enhanced oxygen evolutio...This work demonstrates that in situ formation of carbonate layer on the surface of Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF)obtained by exposure to CO2 during heating between 500℃ and 700℃ can provide enhanced oxygen evolution reaction(OER)performance and durability in an alkaline solution relative to the original BSCF.Three temperatures,i.e., 500℃,600℃,and 700℃ were chosen to perform the CO2 thermal treatment,resulting into BSCF-500,BSCF-600,and BSCF-700 samples.The OER was enhanced in the order of BSCF-500< BSCF-700 < BSCF-600. BSCF-600 showed the best OER performance, i.e., a low overpotential of 0.36 V required to attain 10 mA cm^-2 current density as well as a mass activity of 74.14 Agcmcat-1 and a specific activity of 5.04 mA cmcat-2 at an overpotential of 0.4 V. The OER performance durability of BSCF-600 was highlighted by its ability to maintain a stable potential of around 1.61 V vs. RHE (RHE: reversible hydrogen electrode) when charged at a constant current density of 10 mA cm^-2 throughout the 800 min continuous chronopotentiometry test. The enhanced OER performance for BSCF-600 relative to the original BSCF is attributed to three factors:(i) higher electrochemically active surface area;(ii) faster charge transfer rate and higher electrical conductivity;and (iii) modified oxidation state of cobalt ions. The formation of thin carbonate layer in BSCF-600 appears to suppress the durability issue observed in BSCF.展开更多
基金supported by the National Natural Science Foundation of China(No.22278203,No.22279057)the support of the Inner Mongolia major science and technology project(2021ZD0042),Development of integrated technology for CO_(2)emission reduction in electric power metallurgy industry
文摘Solid oxide electrolysis cells(SOECs),displaying high current density and energy efficiency,have been proven to be an effective technique to electrochemically reduce CO_(2)into CO.However,the insufficiency of cathode activity and stability is a tricky problem to be addressed for SOECs.Hence,it is urgent to develop suitable cathode materials with excellent catalytic activity and stability for further practical application of SOECs.Herein,a reduced perovskite oxide,Pr_(0.35)Sr_(0.6)Fe_(0.7)Cu_(0.2)Mo_(0.1)O_(3-δ)(PSFCM0.35),is developed as SOECs cathode to electrolyze CO_(2).After reduction in 10%H_(2)/Ar,Cu and Fe nanoparticles are exsolved from the PSFCM0.35 lattice,resulting in a phase transformation from cubic perovskite to Ruddlesden-Popper(RP)perovskite with more oxygen vacancies.The exsolved metal nanoparticles are tightly attached to the perovskite substrate and afford more active sites to accelerate CO_(2)adsorption and dissociation on the cathode surface.The significantly strengthened CO_(2)adsorption capacity obtained after reduction is demonstrated by in situ Fourier transform-infrared(FT-IR)spectra.Symmetric cells with the reduced PSFCM0.35(R-PSFCM0.35)electrode exhibit a low polarization resistance of 0.43Ωcm^(2)at 850℃.Single electrolysis cells with the R-PSFCM0.35 cathode display an outstanding current density of 2947 mA cm^(-2)at 850℃and 1.6 V.In addition,the catalytic stability of the R-PSFCM0.35 cathode is also proved by operating at 800℃with an applied constant current density of 600 mA cm^(-2)for 100 h.
基金supported financially by the National Natural Science Foundation of China(Nos.51502138 and 51506085)the Natural Science Foundation of Jiangsu Province(Nos.BK20150738and BK20150742)
文摘This work demonstrates that in situ formation of carbonate layer on the surface of Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF)obtained by exposure to CO2 during heating between 500℃ and 700℃ can provide enhanced oxygen evolution reaction(OER)performance and durability in an alkaline solution relative to the original BSCF.Three temperatures,i.e., 500℃,600℃,and 700℃ were chosen to perform the CO2 thermal treatment,resulting into BSCF-500,BSCF-600,and BSCF-700 samples.The OER was enhanced in the order of BSCF-500< BSCF-700 < BSCF-600. BSCF-600 showed the best OER performance, i.e., a low overpotential of 0.36 V required to attain 10 mA cm^-2 current density as well as a mass activity of 74.14 Agcmcat-1 and a specific activity of 5.04 mA cmcat-2 at an overpotential of 0.4 V. The OER performance durability of BSCF-600 was highlighted by its ability to maintain a stable potential of around 1.61 V vs. RHE (RHE: reversible hydrogen electrode) when charged at a constant current density of 10 mA cm^-2 throughout the 800 min continuous chronopotentiometry test. The enhanced OER performance for BSCF-600 relative to the original BSCF is attributed to three factors:(i) higher electrochemically active surface area;(ii) faster charge transfer rate and higher electrical conductivity;and (iii) modified oxidation state of cobalt ions. The formation of thin carbonate layer in BSCF-600 appears to suppress the durability issue observed in BSCF.
