The perovskite-type Ba- and Ti/Nb-doped (Ba0.15Sr0.85)(B0.15Co0.85)O3 − δ (B = Ti, Nb) oxides were synthesized successfully by the solid-state reaction method. Crystal structure, elemental compositions, and oxygen nonstoichiometry of the as-synthesized (Ba0.15Sr0.85)(B0.15Co0.85)O3 − δ (B = Ti, Nb) oxides were investigated by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), inductively coupled plasma (ICP)-atomic emission spectrometry, thermogravimetry (TG), and iodometric titration. XRD results demonstrate that the as-obtained (Ba0.15Sr0.85)(B0.15Co0.85)O3 − δ (B = Ti, Nb) oxides possess purely cubic perovskite-type structures. The temperature-swing oxygen sorption/desorption properties of the as-synthesized (Ba0.15Sr0.85)(B0.15Co0.85)O3 − δ (B = Ti, Nb) perovskite-type oxides were studied by the dynamic TG. Results show that the structural stability of the co-doped (Ba0.15Sr0.85)(B0.15Co0.85)O3 − δ (B = Ti, Nb) oxides is improved greatly, and the high oxygen sorption capacity for the perovskite-type (Ba0.15Sr0.85)(B0.15Co0.85)O3 − δ (B = Ti, Nb) oxides is also obtained between 300 and 950 °C in air.

•Porous capillary α-Al2O3 as substrates for the Pd-based membranes preparation.•Pd and Pd–Ni alloy membranes fabricated by the facile electroless plating method.•Pd and Pd–Ni membranes showed good stability and hydrogen permeance/selectivity.Novel home-made porous capillary α-Al2O3 substrates were used as mechanical supports for the Pd-based composite membranes for hydrogen permeation. The rough surface of the substrates with large open pores were modified by vacuum sol–gel dip-coating followed by high temperature calcination treatment. After the introduction of the electroless plating catalysts of Pd particles on the modified surface by an improved catalyzing process, the defect-free Pd and Pd–Ni alloy thin membranes were deposited by cost-effective and facile electroless plating technique. The Pd composite membranes showed a hydrogen permeance of 2.55 × 10−3 mol/(s m2 Pa0.5) at 500 °C, and 730 for the permselectivity of H2/N2. The Pd–Ni alloy composite membranes showed a hydrogen permeance of 2.74 × 10−3 mol/(s m2 Pa0.5), and 640 for the permselectivity of H2/N2 at the same temperature. The Pd and Pd–Ni membranes showed good long-term permeation stability at 500 °C under hydrogen permeation condition. Moreover, the Pd–Ni alloy composite membrane showed a better hydrogen permeation stability of more than 100 h at 300 °C under hydrogen permeation condition without obvious hydrogen embrittlement occurred.

A novel surface modification strategy was developed using 3-aminopropytriethoxysilane and 4-formylphenylboronic acid successively as covalent linkers between COF-5 and the porous α-Al2O3 ceramic support, and then the COF-5 membrane was further grown successfully on the modified α-Al2O3 support by using a microwave irradiation method.

•A covalent linkage by 3-aminopropytriethoxysilane (APTES) for the Schiff-base networks (SNW).•The SNW-1 membrane fabricated on the APTES modified porous α-Al2O3 support.•The supported SNW-1 membrane synthesized by the catalyst-free polycondensation method.A surface modification strategy was applied by using 3-aminopropyltriethoxysilane (APTES) covalent linkage between the Schiff-base networks (SNW) polymer layers and porous α-Al2O3 ceramic support. The SNW-1 polymer membrane and powders resulting from the polycondensation reaction between melamine and terephthalaldehyde without the polycondensation catalysts were investigated by SEM and FT-IR. The results show that the discrete and few covered polymer layers were formed on the unmodified porous α-Al2O3 support. In contrast, the uniform and compact SNW-1 polymer membrane was fabricated successfully on the APTES modified α-Al2O3 support by in-situ catalyst-free polycondensation method, indicating that the APTES surface modification facilitates the growth of the novel SNW-1 polymer membrane on the porous α-Al2O3 support.

The novel Fe/Nb co-substituted SrCo1−2x(Fe,Nb)xO3−δ (x = 0.05, 0.10) oxides have been synthesized and characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG), and scanning electron microscopy (SEM). The XRD and DSC results demonstrate that the structural stability of the Fe/Nb co-substituted samples x = 0.05, 0.10 is improved greatly compared to the sample x = 0.00. The Fe/Nb co-doping in the SrCoO3−δ oxide results in the improved structural stability of the SrCo1−2x(Fe,Nb)xO3−δ (x = 0.05, 0.10) oxides. The nonstoichiometric and sintering properties were investigated by TG and SEM, and the oxygen permeation fluxes were measured at 800–950 °C for the sample x = 0.10. The improved oxygen permeability of the ceramic SrCo1−2x(Fe,Nb)xO3−δ (x = 0.10) membrane compared to the (Ba0.5Sr0.5)(Co0.8Fe0.2)O3−δ and SrCo0.8Fe0.2O3–δ membranes, was observed under an air/He oxygen partial pressure gradient at 800–950 °C.Highlights► The novel Fe/Nb co-substituted SrCo1−2x(Fe,Nb)xO3−δ (x = 0.05, 0.10) oxides were characterized by the XRD, DSC, TG and SEM–EDS. ► The high structural stability of the co-substituted SrCo1−2x(Fe,Nb)xO3−δ (x = 0.05, 0.10) oxides. ► The excellent oxygen permeation performance of the co-substituted SrCo1−2x(Fe,Nb)xO3−δ (x = 0.10) membrane.

The novel Fe/Nb/Ti co-substituted Sr(Co0.8Fe0.1Nb0.1)1−xTixO3−δ (x = 0.00, 0.20, 0.40) oxides have been synthesized by the solid-state reaction method. These co-substituted strontium cobaltates possess a cubic perovskite-type structure at room temperature. Structural stability and sintering properties of the samples x = 0.00, 0.20, 0.40 were investigated by X-ray diffraction (XRD), thermogravimetry (TG), and scanning electron microscopy. The combined TG and XRD results demonstrate that the structural and chemical stability of the Fe/Nb/Ti co-substituted Sr(Co0.8Fe0.1Nb0.1)1−xTixO3−δ (x = 0.20, 0.40) oxides is improved greatly compared with the sample x = 0.00 and the Ba0.5Sr0.5Co0.8Fe0.2O3−δ oxide.

The spontaneous oscillations of the cell voltage and output power density of a PEMFC (with PtRu/C anode) using CO-containing H2 streams as anodic fuels have been observed during galvanostatic operating. It is ascribed to the dynamic coupling of the CO adsorption (poisoning) and the electrochemical CO oxidation (reactivating) processes in the anode chamber of the single PEMFC. Accompanying the cell voltage and power density oscillations, the discrete CO concentration oscillations at the anode outlet of the PEMFC were also detected, which directly confirms the electrochemical CO oxidation taking place in the anode chamber during galvanostatic operating.

The novel Fe/Nb co-doped SrCo1 − 2x(Fe,Nb)xO3 − δ (x = 0.05, 0.10) perovskite oxides were synthesized by the solid-state method. Structural and chemical stability of the SrCo1 − 2x(Fe,Nb)xO3 − δ (x = 0.05, 0.10) oxides were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and X-ray diffraction (XRD). The results demonstrated that the structural and chemical stability of the Fe/Nb co-doped SrCo1 − 2x(Fe,Nb)xO3 − δ (x = 0.05, 0.10) is improved significantly. The oxygen sorption properties of the SrCo1 − 2x(Fe,Nb)xO3 − δ (x = 0.05, 0.10) oxides were investigated between 300–900 °C in air, and the high oxygen sorption capacity of 11.5 and 10.3 mL O2 (STP)/g oxide, respectively, are obtained.Highlights► The novel co-doped SrCo1–2x(Fe,Nb)xO3–δ (x = 0.05, 0.10) oxides were synthesized. ► The high structural/chemical stability of the SrCo1–2x(Fe,Nb)xO3–δ (x = 0.05, 0.10). ► The high oxygen sorption properties of the SrCo1–2x(Fe,Nb)xO3–δ (x = 0.05, 0.10).

A novel surface modification strategy was developed using 3-aminopropytriethoxysilane and 4-formylphenylboronic acid successively as covalent linkers between COF-5 and the porous α-Al2O3 ceramic support, and then the COF-5 membrane was further grown successfully on the modified α-Al2O3 support by using a microwave irradiation method.

The spontaneous oscillations of the cell voltage and output power density of a PEMFC (with PtRu/C anode) using CO-containing H2 streams as anodic fuels have been observed during galvanostatic operating. It is ascribed to the dynamic coupling of the CO adsorption (poisoning) and the electrochemical CO oxidation (reactivating) processes in the anode chamber of the single PEMFC. Accompanying the cell voltage and power density oscillations, the discrete CO concentration oscillations at the anode outlet of the PEMFC were also detected, which directly confirms the electrochemical CO oxidation taking place in the anode chamber during galvanostatic operating.