A B-site doped perovskite ferrate as an efficient anode of a solid oxide fuel cell with in situ metal exsolution

Abstract

With engineering of A-site deficiency and Ti4+/3+ stabilization, Ni0 exsolves and embeds partially in the perovskite under in situ reduction.

Pr and Mo Co‐Doped SrFeO3–δ as an Efficient Cathode for Pure CO2 Reduction Reaction in a Solid Oxide Electrolysis Cell

“…Moreover, the calculated ratio of Fe 2+ to Fe 3+ is increased to 1.29, whereas the average Fe valence state is decreased to +2.44. At the same time, it can be concluded from Figure S3a, Supporting Information, that a mixed valence state, reflected by two fitting peaks with binding energies of 232.2 eV for Mo 5+ 3d 5/2 and 232.9 eV Mo 6+ 3d 5/2 , [8c,8d] is also detected for Mo 3d in fresh PSFM powders, and the average valence state is calculated to be +5.89 with a Mo 5+ /Mo 6+ ratio of 0.11:0.89. However, due to the reduction, the calculated Mo 5+ /Mo 6+ ratio is increased to 0.15:0.85, and the average Mo valence state is decreased to +5.85.…”

“…As the electrocatalytic properties and electrical conductivity of PSFM material are strongly associated with the valence states of B‐site transition metals (Fe and Mo), the XPS spectra for Fe 2p and Mo 3d signals have been systematically analyzed, and the XPS spectra and corresponding fitting curves of Fe 2p and Mo 3d are shown in Figure 1c,d and Figure S3a,b, Supporting Information, respectively. It can be clearly observed from Figure 1c,d that two typical peaks with the binding energy of 712.1 and 710.1 eV, which are identified as Fe 3+ 2p 3/2 and Fe 2+ 2p 3/2 , [8n,8o] respectively, are observed for Fe element in fresh PSFM powders. In addition, the ratio of Fe 2+ to Fe 3+ is calculated to be 0.55, and the average valence state for Fe element is calculated to be +2.65, indicating a mixed valence state for Fe element.…”

“…[ 8 ] It is demonstrated that these in situ exsolved metallic nanoparticles can strongly facilitate CO 2 adsorption and CO bond activation, reasonably enhancing the rate of CO 2 RR [6f] . Moreover, these in situ exsolved metallic nanoparticles are strongly pinned into the parent oxides, resulting in a robust stability against metallic nanoparticles aggregation and carbon coking during the operation [8f,9] . Due to its low cost, high electrocatalytic activity, and good stability, more and more attention has been paid on in situ exsolved metallic Fe nanoparticles–structured perovskite oxide electrodes.…”

“…As clearly shown in Figure 3b, the electrolysis current density of 0.71 A cm −2 for PSFM cathode is much higher than 0.05 A cm −2 for La 0.2 Sr 0.8 TiO 3− δ (LST) cathode, [ 15 ] 0.15 A cm −2 for La 0.2 Sr 0.8 Ti 0.9 Mn 0.1 O 3+ δ (LSTM) cathode, [6e] 0.10 A cm −2 for La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3– δ (LSCrM) cathode, [4c] 0.28 A cm −2 for La 0.3 Sr 0.7 Fe 0.7 Ti 0.3 O 3 (LSFT) cathode, [4e] and 0.14 A cm −2 for (Pr,Ba) 2 Mn 2 O 5+δ (LPBM) cathode [10d] . It is also found that PSFM cathode exhibits a much better electrochemical performance than some SFM‐based cathode, such as 0.22 A cm −2 for SFM cathode, [ 16 ] 0.38 A cm −2 for SFM‐SDC composite cathode, [8a] and 0.45 A cm −2 for GDC‐infiltrated SFM cathode. [ 16 ] More importantly, the performance is better than some in situ exsolved metallic Fe nanoparticles–structured ceramic electrodes, for example, 0.53 A cm −2 for Fe@(Pr,Ba) 2 Mn 2– y Fe y O 5+ δ (LPBMF) cathode [10d] and 0.43 A cm −2 for Fe@SFM cathode [10g] .…”

Improved electrochemical performance and durability of butane‐operating low‐temperature solid oxide fuel cell through palladium infiltration

“…Effective efforts have been tried to solve the coking deposition over hydrocarbon steam reforming, and considerable progress has been obtained in recently. [20][21][22][23] The first method to suppress carbon deposition is by controlling the steam-to-carbon ratio (SCR). The SCR is the ratio of reactant water molecules to the number of carbon atoms in a hydrocarbon.…”