Perovskite Oxyfluoride Ceramic with In Situ Exsolved Ni–Fe Nanoparticles for Direct CO₂ Electrolysis in Solid Oxide Electrolysis Cells

Abstract

Solid oxide electrolysis cell (SOEC) is a potential technique to efficiently convert CO 2 greenhouse gas into valuable fuels. Thus, there is significant interest in developing highly active and stable electrocatalysts for the CO 2 reduction reaction (CO 2 RR). Herein, a Ni and F co-doping strategy is proposed to facilitate the exsolution reaction and form a new cathode, Ni−Fe alloy nanoparticles embedded in ceramic Sr 2 Fe 1.5 Mo 0.5 O 6−δ (SFM) doped with fluorine. F-doping and Ni−Fe exsolution enhance CO 2 adsorption by a factor of 2.4 and increase the surface reaction rate constant (k chem ) for CO 2 RR from 6.79 × 10 −5 to 18.1 × 10 −5 cm s −1 , as well as the oxygen chemical bulk diffusion coefficient (D chem ) from 9.42 × 10 −6 to 19.1 × 10 −6 cm 2 s −1 at 800 °C. Meanwhile, the interfacial polarization resistance (R p ) decreases by 52%, from 0.64 to 0.31 Ω cm 2 . At 800 °C and 1.5 V, an extremely high current density of 2.66 A cm −2 and a stability test over 140 h are achieved for direct CO 2 electrolysis in the SOEC.

Electrochemical Performance of Pr0.4Sr0.5CoxFe0.9–xMo0.1O3−δ Oxides in a Reversible SOFC/SOEC System

“…From Figure e, it can be seen that the oxygen on the surface of R-PSCFM can be divided into three categories at around 531.4, 529.9, and 528.7 eV corresponding to surface oxygen species (O surf ), adsorbed oxygen species (O ads ), and lattice oxygen (O latt ), respectively. It has been demonstrated that O ads is closely correlated to oxygen vacancies, and the higher the O ads content, the higher the amount of oxygen vacancies. , Therefore, as shown in Figure f, the order of oxygen vacancy content is R-PSCFM-1 > R-PSCFM-2 > R-PSCFM-4 > R-PSCFM-3.…”

“…It has been demonstrated that O ads is closely correlated to oxygen vacancies, and the higher the O ads content, the higher the amount of oxygen vacancies. 11,31 Therefore, as shown in Figure 5f, the order of oxygen vacancy content is R-PSCFM-1 > R-PSCFM-2 > R-PSCFM-4 > R-PSCFM-3.…”

Boosting H2O2 Activation for the Efficient Degradation of Dimethyl Sulfoxide-Containing Wastewater over Supported Niobia Catalysts

“…The O 1s spectra of the fresh and used catalysts are deconvoluted into two peaks. The peak at 530.7 eV represents lattice oxygen (O L ), and the higher binding energy at 532.8 eV corresponds to surface oxygen species (O S ), including O 2 2– , O – , hydroxyl, and carbonates, and so on (Figure d). ,,, The ratios of O S /O L are 12.2 and 9.3 for the fresh and used Nb 2 O 5 /SiO 2 catalysts, respectively. After the DMSO degradation reaction, the contents of lattice oxygen increased and the contents of surface oxygen species decreased.…”

A mini review of the recent progress of electrode materials for low-temperature solid oxide fuel cells

“…Subsequently, the NiFe nanoparticles facilitated the gas dissociation processes. Besides, Li and coworkers 23 synthesized the nonstoichiometric Zhang et al 24 proposed a Ni and F co-doping strategy and prepared the A-site deficient double perovskite Sr 1.9 Fe 1.5 Mo 0.4 -Ni 0.1 O 6Àd F 0.1 (SFMNi-F). The A-site deficiency suppressed the Sr segregation and stabilized the matrix phase.…”

“…Zhang et al 24 proposed a Ni and F co-doping strategy and prepared the A-site deficient double perovskite Sr 1.9 Fe 1.5 Mo 0.4 Ni 0.1 O 6− δ F 0.1 (SFMNi-F). The A-site deficiency suppressed the Sr segregation and stabilized the matrix phase.…”