A zeolitic imidazolate framework (ZIF-8) as member of the metal−organic family has been crystallized a thin porous layer on an asymmetric ceramic support. Hydrogen can be selected from other gases by molecular sieving.

Molecular strainer: An ultramicroporous zeolitic imidazolate framework (ZIF-7) was tested for its gas-separation properties in membrane applications. ZIF-7 appended to an asymmetric alumina support using microwave-assisted seeded growth, and the resulting exhibits high H2 selectivity as a molecular sieve has excellent thermal stability.

Molekularer Seiher: Das ultramikroporöse zeolithische Imidazolatgerüst ZIF-7 wurde bezüglich seiner Eignung zur Gastrennung an Membranen untersucht. Dazu es mithilfe von mikrowellengestütztem gezieltem Wachstum auf einen asymmetrischen Aluminiumoxidträger aufgebracht. Die erhaltene Membran war thermisch stabil und als Molekularsieb hoch H2-selektiv. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited...

Abstract Direct decomposition of N 2 O to using perovskite hollow fiber membranes is achieved by combination with in situ oxygen removal (see picture). A coupled partial methane oxidation allows ‐free synthesis gas be obtained. This sustainable process combines the simultaneous production valuable chemicals. magnified image

A novel cobalt-free and noble metal-free dual-phase oxygen-transporting membrane with a composition of 40 wt % Pr0.6Sr0.4FeO3−δ–60 Ce0.9Pr0.1O2−δ (40PSFO–60CPO) has been successfully developed via an in situ one-pot one-step glycine-nitrate combustion process. In XRD demonstrated that the 40PSFO–60CPO shows good phase stability not only air but also 50 vol CO2/50 N2 atmosphere. When using pure He or CO2 as sweep gases, at 950 °C steady oxygen permeation fluxes 0.26 cm3 min–1 cm–2 0.18 are...

To combine good chemical stability and high oxygen permeability, a mixed ionic-electronic conducting (MIEC) 75 wt% Ce(0.85)Gd(0.1)Cu(0.05)O(2-δ)-25 La(0.6)Ca(0.4)FeO(3-δ)(CGCO-LCF) dual-phase membrane based on MIEC-MIEC composite has been developed. Copper doping into Ce(0.9)Gd(0.1)O(2-δ) (CGO) oxide enhances both ionic electronic conductivity, which then leads to change from conduction at elevated temperatures. For the first time we demonstrate that an intergranular film with 2-10 nm...

A novel neutral and cation-free LTA-type AlPO(4) membrane has been prepared on porous asymmetric ceramic supports. Hydrogen can be effectively separated from other gases by molecular sieving.

By cobalt-doping of the mixed conducting phase PSFC, a good combination high CO2 stability and oxygen permeability is obtained for 60 wt% Ce(0.9)Pr(0.1)O(2-δ)-40 Pr(0.6)Sr(0.4)Fe(0.5)Co(0.5)O(3-δ) (CP-PSFC) dual membrane, which suggests that CP-PSFC promising membrane industrial applications in oxyfuel process capture.

Phase stability and oxygen permeation behavior of Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) dead-end tube membranes were investigated in long-term production at 950 750 °C. At °C, the BSCF exhibit good phase a stable flux. However, intermediate temperature both flux purity decrease continuously. This is related to formation two secondary phases that are hexagonal perovskite, Ba0.5±xSr0.5±xCoO3−δ, trigonal mixed oxide, Ba1–xSrxCo2–yFeyO5, evolved ceramic membrane made cubic perovskite during dynamic...

CO2-stable oxygen-permeable Fe2O3 (FO) - Ce0.9Gd0.1O2-δ (CGO) dual phase composite membranes of the composition χ wt % FO (100 – χ) CGO with = 25, 40, 50 were successfully prepared via a one-pot single-step method. X-ray diffraction (XRD) demonstrated that all after sintering at 1300 °C for 5 h represent microscale mixture only two pure phases and CGO. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDXS), oxygen permeation revealed microstructure has great influence on...

We report a novel CO₂-stable reduction-tolerant dual-phase oxygen transport membrane 40 wt% Nd_0.6Sr_0.4FeO_3−δ–60 Ce_0.9Nd_0.1O_2−δ. This material shows good reversibility of the permeation fluxes, stability in CO₂atmosphere and under harsh conditions partial oxidation methane to synthesis gas up 950 °C.

High oxygen permeability and good thermochemical stability of oxygen-transporting membranes (OTMs) are two main requirements concerning the applicability these devices in chemical processes, such as CO2 capture using oxyfuel concept or catalytic membrane reactors. In this work, a single-phase perovskite-type Pr0.6Sr0.4Co0.5Fe0.5O3-δ (PSCF) with 0.6-mm thickness was subjected to periodic thermal cycling temperature range between 850 1000 °C 1000-h long-term permeation test pure sweep gas. The...

Previously unreleased compositions of (Ba0.5Sr0.5)(Fe1−xAlx)O3−δ perovskites in the range 0≤ x ≤ 0.2 were synthesized and studied with respect to electronic crystallographic structure, as well oxygen permeation. The perovskite phase all oxides was found be cubic, without any impurities for aluminum fractions = 0.01−0.09. Electron energy-loss spectroscopy (EELS) revealed a significant amount covalency by Fe-3d−O-2p hybridization mixed Fe3+ /Fe4+ valence state iron perovskites, which...

A porous perovskite BaCo(x)Fe(y)Zr(0.9-x-y)Pd(0.1)O(3-delta) (BCFZ-Pd) coating was deposited onto the outer surface of a BaCo(x)Fe(y)Zr(1-x-y)O(3-delta) (BCFZ) hollow-fiber membrane. The morphology modified BCFZ fiber characterized by scanning electron microscopy (SEM), indicating formation BCFZ-Pd layer on dense oxygen permeation flux membrane with increased 3.5 times more than that blank when feeding reactive CH(4) side and surface-modified were used as reactors to shift equilibrium...

Partial La-substitution for Fe on the B-site of perovskite BaFe0.95−xLaxZr0.05O3−δ (BFLZ) was achieved by applying a sol–gel synthesis method. The highest La content in BFLZ formation pure cubic structure without any detectable impurities is about x = 0.04. It found first time that introduction mixed oxide stabilizes structure. Furthermore, increases significantly oxygen permeability. maximum permeation flux La-content 0.04 with largest volume unit cell, reaching 0.63 and 1.24 cm3 (STP)...

Zeolitic imidazolate framework‐8 (ZIF‐8) with high stability and porosity is a promising candidate for hydrogen separation membranes. However, most ZIF‐8 polycrystalline membranes exhibit low H2/CO2 (kinetic diameters of 2.9/3.3 Å) mixed gas selectivity, due to the intercrystalline defects unprecise molecular sieving originated from framework flexibility structure theoretical aperture size 3.4 Å. Here, inspired by nacre’s “brick‐and‐mortar” structure, we develop matrix type composite in...

Zeolitic imidazolate framework‐8 (ZIF‐8) with high stability and porosity is a promising candidate for hydrogen separation membranes. However, most ZIF‐8 polycrystalline membranes exhibit low H2/CO2 (kinetic diameters of 2.9/3.3 Å) mixed gas selectivity, due to the intercrystalline defects unprecise molecular sieving originated from framework flexibility structure theoretical aperture size 3.4 Å. Here, inspired by nacre’s “brick‐and‐mortar” structure, we develop matrix type composite in...