Various influence of surface modification on permeability and phase stability through an oxygen permeable membrane

Roadmap for Sustainable Mixed Ionic‐Electronic Conducting Membranes

“…[5,6] Oxygen permeable membranes have been intensively investigated in the past decades and can be generally grouped into two types: single-phase and dual-phase (see Figure 2). [1,2,[15][16][17][18][19][20][21][22][23][24]7,[25][26][27][28][29][30][31][32][33][34]8,[35][36][37][38][9][10][11][12][13][14] Currently, Ba-, Sr-, or Co-containing single-phase perovskite-type oxygen-transporting membranes (OTMs) with a general formula of ABO 3 show high oxygen permeation and generally have an oxygen permeation flux of more than 1 mL min −1 cm −2 at 1173 K for a 1 mm-thick membrane. [1,2] However, these OTMs have a poor stability in the presence of CO 2 due to the formation of carbonates.…”

“…An attractive alternative to perovskite is single-phase K 2 NiF 4 -type (Ruddlesden-Popper phase) membrane, which has shown to be completely CO 2 tolerant during long-term stability tests under CO 2 atmosphere. [2,[7][8][9]33,34] Similarly, dual-phase membranes have also displayed high CO 2 resistance after long-term CO 2 exposure. No formation of carbonate or phase change are noticed.…”

“…[1,14,[36][37][38][15][16][17][18][29][30][31]35] Coating a catalyst layer or surface modifications on CO 2 resistant dual-phase and K 2 NiF 4 -type membranes can largely enhance the surface exchange kinetics resulting in the improvement of the oxygen permeability. [1,2,9] Still, these membranes have much lower oxygen permeability than perovskite-type oxygen permeable membranes despite having better chemical and phase stability. It is challenging to achieve high oxygen permeation flux and good chemical stability at the same time.…”

Mixed Oxygen Ionic and Electronic Conducting Membrane Reactors for Pure Chemicals Production

“…To improve the oxygen permeation performance, several strategies were applied, such as the introduction of A-site deficiencies [22,23], anion doping [24,25], surface modification [26,27], and optimizing preparation procedures [32]. For example, Xue et al [28] first used anion doping strategy to develop a (Pr 0.9 La 0.1 ) 2.0 (Ni 0.74 Cu 0.21 Ga 0.05 )O 4+δ Cl 0.1 ((PL) 2.0 NCGCl 0.1 ) membrane, which showed a stable oxygen flux of 1.1 mL min -1 cm -2 at 975 °C. When the membrane was coupled with partial oxidation of methane (POM) reaction for syngas production and an oxygen permeation flux of 5 mL min -1 cm -2 , a methane conversion of 99.9 %, and a CO selectivity of 97.5 % at 900 °C were obtained.…”

Oxygen-permeable ceramic membrane with improved mediate-temperature stability based on partially A-site doped KxSr1-xCo0.8Fe0.2O3-δ

“…Therefore, while the membrane thickness of K 0.1 Sr 0.9 Co 0.8 Fe 0.2 O 3-δ sample is decreased to 0.5 mm, it is ineffective to improve its oxygen permeation flux by further reducing the membrane thickness. The surface modification treatment with some highly active catalysts should be considered when designing practical membrane modules [38,39].…”