Dense Perovskite, La1‐xA′xFe1‐yCoyO3‐δ (A′= Ba, Sr, Ca), Membrane Synthesis, Applications, and Characterization

La 1‐ x A′ x Fe 0.8 Co 0.2 O 3‐δ (A′= Ca, Sr, Ba) perovskite powders were synthesized to attain the desired properties of high O 2 flux and stability under reducing conditions. Steady‐state oxygen permeation rates for La 1‐ x A′ x Fe 0.8 ‐Co 0.2 O 3‐δ perovskite membranes in nonreacting experiments with air on one side and helium on the other side of the membrane were in the order A′ x = Ba 0.8 > Ba 0.6 > Ca 0.6 > Sr 0.6 . Partial oxidation of methane to syngas (CO + H 2 ) was performed in a dense La 0.2 Ba 0.8 Fe 0.8 Co 0.2 O 3‐δ membrane reactor at 850°C in which oxygen was separated from air and simultaneously fed into the methane stream. The reducing atmosphere affected the membrane reaction‐side surface while barium enrichment occurred on the air‐side surface. Oxygen continuously transported from the air side appeared to stabilize the membrane interior, and the reactor was operated for up to 850 h.