In situ high temperature X-ray photoelectron spectroscopy study of barium strontium iron cobalt oxide

La0.6Sr0.4Co0.8Ga0.2O3‐δ (LSCG) hollow fiber membrane reactor: Partial oxidation of methane at medium temperature

“…The reactants were dissolved in the appropriate molar ratios in DI water and stirred and heated to 55 C. Upon drying, the catalyst support was placed in an oven and left to dry overnight at 100 C. A calcination temperature of 900 C for 6 h was then employed to facilitate the solid-state diffusion for perovskite phase to form LaAlO 3 -Al 2 O 3 structure. 5 wt % Ni was then impregnated on the LaAlO 3 -Al 2 O 3 supports and upon drying overnight, the catalyst was calcined at 400 C for 1 h (for nitrate decomposition) and further to 600 C for 5 h.…”

“…53,54 The higher BE about 133.8-135.8 eV suggests presence of SrO species. 54,55 Based on Figure 8 and Table 1, for the fresh LSCG hollow fiber membrane, the external surface shows that the Sr element exists mainly in the form of SrCO 3 (due to atmospheric contamination) and Sr 21 . The internal surface, however, consists mainly of SrO species with a lesser percentage of Sr 21 in the perovskite phase.…”

“…During the POM reaction, the reducing nature of the permeate side can cause the membrane to undergo deleterious changes to its surface structure. 55 This leads to enhanced electronic activity due to the hydrocarbon degradation taking place, whereby the strongly reducible nature of Co 31 will induce transformation to Co 21 which has stable half-filled orbits containing stable electron distribution of t 2g 5 e g 2 . 60 As can be observed from Figure 9 and Table 1, upon exposure to the reducing gases, the Co2p 3/2 peak appear to shift to lower binding energies, indicating the presence of Co have also been observed by Petunchi and Lombardo during reduction of LaCoO 3 under H 2 .…”

On the structural stability and oxygen permeation behavior of inorganic SrCo0.8Fe0.2O3−δ membranes

“…5 m m a s ∼1.41 ml cm −2 min −1 for about ∼60 h only. Jo 2 decreases thereafter slowly by ∼7 % in next 60 h. Nevertheless, Jo 2 value is greater than 1.0 ml cm −2 min −1 set for economic and industrial viability consideration [34]. The oxygen permeability of SrCo 0.8 Fe 0.2 O 3−δ membrane no doubt lies within the acceptable limit but its sustainability is somewhat poor and requires improvement.…”

“…7b in the energy range 701-741 eV reveals information about the oxidation states of iron. The peak broadness suggests the presence of all Fe 3+ , Fe 2+ , and Fe 4+ ions but arises due to electrostatic interactions, spin-orbit coupling between the 2p core hole and unpaired 3d electrons of the photoionized cation, and crystal field effects [34,35]. Yunfei et al [32] have classified peaks for Fe 2p 3/2 in the energy range of 709.6-709.9 eV, 710.9-711.9 eV, and 712-714 eV as 7b and Table 3).…”