Efficient and CO2-tolerant oxygen transport membranes prepared from high-valence B-site substituted cobalt-free SrFeO3−δ

Perovskite materials in energy storage and conversion

“…The development of cobalt‐free perovskite membranes with intrinsically high stability has been pursued intensively. In considering the higher chemical stability of iron ions relative to cobalt ions, many iron‐based perovskite oxides have been developed as materials for ceramic oxygen‐permeating membranes, for applications in membrane reactors . For example, a Ba 0.5 Sr 0.5 Zn 0.2 Fe 0.8 O 3 − δ (BSZF) perovskite oxide was reported by Wang et al as a new cobalt‐free perovskite material for use in oxygen‐permeating membranes .…”

“…Later, some other BaFeO 3 ‐based materials, such as BaNb y Fe 1 − y O 3 − δ and BaFe 0.95 − x La x Zr 0.05 O 3 − δ , were also reported to have promising oxygen‐permeating performances . It is important to note that a series of B site‐doped SrFeO 3 − δ perovskite materials in these newly developed Co‐free materials also exhibited rather strong chemical resistance to CO 2 poisoning but relatively poor oxygen‐permeating ability …”

Highly Active and Stable Cobalt-Free Hafnium-doped SrFe0.9Hf0.1O3−δ Perovskite Cathode for Solid Oxide Fuel Cells

“…However, the applied method is also time-consuming and the desired cathode architecture is hard to be precisely prepared. According to literature, the susceptibility to CO 2 poisoning of perovskite-type oxides was closely related to the thermodynamics of carbonates, average metal–oxygen bond energy (ABE), Lewis acidity, and oxygen vacancy concentration. ,, Recently a doping strategy has been widely employed to improve the CO 2 tolerance. The picked dopants should possess characteristics of (1) high acidity, (2) high valence state, and (3) high ABE .…”

“…The picked dopants should possess characteristics of (1) high acidity, (2) high valence state, and (3) high ABE . Ti 4+ , Zr 4+ , Nb 5+ , Sb 5+ , Ta 5+ , W 6+ , and Mo 6+ could probably help mediate the CO 2 poisoning effects of perovskites. − Very recently, we have found that Co-free high-valence and redox-inactive transition metal cations doped SrFeO 3−δ (SF) membranes showed effectively improved CO 2 tolerance. , The balance of the oxygen permeability and the CO 2 tolerance was taken seriously in our previous reports when developing perovskite-type materials for practical membrane applications. To the best of our knowledge, only a few studies have simultaneously investigated the activity and chemical stability in developing cathode materials for SOFCs. , …”

Development of CO2 tolerant cathode materials for low-temperature solid oxide fuel cells

“…Recently, B-site doping with dopants with characteristics such as high metal−oxygen bond energy (ABE), high valence state and high acidity has been widely used to enhance the CO2 tolerance [217][218][219] . The dense LSM layer prevents the carbonate formation on the BSCF surface which keeps the polarization resistance stable before and after a supply of 10 % CO2 225 .…”