Novel proton-conducting layered perovskite based on BaLaInO4 with two different cations in B-sublattice: Synthesis,hydration, ionic (O2−, H+) conductivity

The present study focused on the novel material with significantly improved properties for the application in the area of clean energy. The new complex oxide BaLaIn_0·5Y_0·5O₄ with layered perovskite structure was obtained for the first time. It was proved that the introduction of Y³⁺ ions in the perovskite layer of BaLaInO₄ leads i) to the rise of the oxygen-ionic conductivity due to the increase in mobility of oxygen ions as a result of the expand of the cell volume and ii) to the enhancement of protonic conductivity due to the increase in the proton concentration and mobility. The sample BaLaIn_0·5Y_0·5O₄ is nearly pure proton conductor below 400 °C and has the protonic conductivity value 1.6?10^?5 S/cm at this temperature.     

Ionic (O2−, H+) transport in novel Zn-doped perovskite LaInO3

For the first time the LaIn_1-xZn_xO_3-1/2x samples was synthesized via solid-state reaction method. The Zn²⁺−doping effect on the B-site of LaInO₃ on structure, water uptake and electrical properties was investigated. The results show that Zn²⁺ is good alternative to alkaline earth metals. The Zn-doping decreases the sintered temperature and makes it possible to obtain high-density ceramics. The substitution increases the conductivity by ∼2 orders of magnitude. Below ∼500 °C the phases exhibit the dominant oxygen-ionic transport (dry atmosphere), and the dominant protonic transport below 600 °C (wet atmosphere). The obtained results suggest the prospects for using these materials in the Hydrogen Energy field. A new concept of the ability of perovskite phases LaBO₃ to incorporate water has been proposed. In addition to the presence of oxygen vacancies, their size, which depends on the B-cation nature, is of decisive importance in the hydration process and the formation of proton conductivity.     

Molybdenum substitution at the B-site of lanthanum strontium titanate anodes for solid oxide fuel cells

The effects of Mo doping into the B-site of La_0.3Sr_0.7TiO_3-δ perovskite on its ionic conductivity and catalytic activity as an anode material of solid oxide fuel cells have been investigated. The partial substitution of Ti by Mo reduces the bond energy between metal and oxygen ions in the perovskite. The concentration of Mo⁵⁺/Mo⁶⁺ redox couples increases with the rise of the content of Mo, while the oxygen ionic conductivity decreases simultaneously. The doping of Mo significantly reduces the anodic polarization resistance and improves the performance of the single cell. The cell with La_0.3Sr_0.7Ti_0.97Mo_0.03O_3-δ anode and La_0.8Sr_0.2Ga_0.8Mg_0.2O_3-δ electrolyte exhibits a maximum power density of 135 mW cm^?2 at 850 °C with hydrogen as fuel.     

Tuning oxygen vacancy of the Ba0·95La0·05FeO3−δ perovskite toward enhanced cathode activity for protonic ceramic fuel cells

Innovation of highly active cathode is of great significance to the development of protonic ceramic fuel cells (PCFCs). Herein, tailoring oxygen vacancies in Zn-doped Ba_0·95La_0·05FeO_3?δ (BLFZ) perovskite is proved to be beneficial for promoting the formation of proton defects. Hydration ability of the triple conducting BLFZ perovskites is confirmed by electrical conductivity relaxation (ECR). The results demonstrate that BLFZ exhibits a proton surface exchange coefficient of 1.34 × 10^?3 cm s^?1 at 600 °C, which greatly extends active sites from the electrolyte/cathode interface to the entire electrode. Mechanism and process elementary steps of the oxygen reduction reaction (ORR) of BLFZ-BaCe_0.7Zr_0·1Y_0.1Yb_0.1O_3?δ (BCZYYb) are detailedly studied. It is found that the rate-determining step of ORR is surface dissociative adsorption of oxygen on BLFZ-BCZYYb cathode. A maximum power density of 673 mW cm^?2 at 700 °C is achieved and BLFZ-BCZYYb based single-cell shows no obvious degradation at 600 °C for 200 h. The good performance is ascribed to the rapid proton diffusion of BLFZ-BCZYYb composite electrode by regulating the oxygen vacancies.     

Cation and oxyanion doping of layered perovskite BaNd2In2O7: Oxygen-ion and proton transport

Proton-conducting electrochemical devices such as protonic ceramic fuel cells and protonic ceramic electrolysis cells play a major role in the creation of eco-friendly “green” energy systems. The most studies of proton-conducting materials for these devices are barium cerate zirconates. The layered perovskites are novel class of proton-conducting materials. In this paper, the possibility of cation and oxyanion doping of layered perovskite BaNd₂In₂O₇ was carried out for the first time. The most conductive composition BaLa_1.9Sr_0.1In₂O_6.95 demonstrates protonic conductivity value 2·10⁻⁵ S/cm at 450 °C. The acceptor-doped two-layer perovskites are the prospective class of proton-conducting materials, and further modification of their composition opens up a new way in the design of solid oxide protonic conductors.     

Advanced fuel cell based on semiconductor perovskite La–BaZrYO3-δ as an electrolyte material operating at low temperature 550 °C

As an electrolyte, enough ionic conductivity, either proton (H⁺) or oxide (O²⁻) conduction, has demanded the better performance of low-temperature (especially below 550 °C) solid oxide fuel cell (LT-SOFCs). Notably, that either conductivity, higher performance, reliability, or higher cost is hampering the LT-SOFC marketing. In our current subject, we report the La-doped BZY proton conductor as an electrolyte has exhibited high ionic conductivity of 0.15 S/cm with a higher performance of 0.78 W/cm² at 550 °C. Also, the performance of LBZY is superior to the un-doped BZY electrolyte. Such high performance mainly ascribed due to the doping of La into BZY. Besides, the mechanism for high ion conductivity is explained. This work manifests that using the LBZY semiconductor perovskite as an electrolyte is more suitable for fuel cell technology.     

Ba0·5Sr0·5(Co0·8Fe0.2)1-xTaxO3-δ perovskite anode in solid oxide electrolysis cell for hydrogen production from high-temperature steam electrolysis

Among perovskite anodes in solid oxide electrolysis cell (SOEC), Ba_0·5Sr_0·5Co_0·8Fe_0·2O_3-δ (BSCF) has gained much attention due to its dominantly high performance. However, the BSCF still suffers from chemical instability. In this study, the B-site of BSCF is partially substituted by a higher valence Ta⁵⁺ (5, 10, 15 and 20 mol%) to improve its structural stability - Ba_0·5Sr_0·5(Co_0·8Fe_0.2)_1-xTa_xO_3-δ (BSCFTax, 0 ≤ x ≤ 0.20). It is found that doping with higher valence Ta⁵⁺ increases both chemical stability and electrochemical performance of BSCF. Although the BSCFTa0.10 shows the lowest oxygen vacancies indicating by the ratio of adsorbed oxygen vacancies (O_adsorbed) to lattice oxygen (O_lattice), the electrochemical performance increases. The decrease in Co³⁺/Co⁴⁺ ratio results in increasing electronic conductivity in the anode. It is likely that proper amount of Ta⁵⁺ doping provide a balance between ionic and electronic conductivity in the anode and improved electrochemical performance. The symmetrical half-cells with electrolyte support (BSCFTa/YSZ/BSCFTa) are fabricated to determine the area specific resistance (ASR) and activation energy of conduction - BSCFTa0.10 shows the best performance. Cathode-supported Ni-YSZ/YSZ/BSCFTa0.10 also shows higher durability than Ni-YSZ/YSZ/BSCF (operating at current density ?0.45 A cm^?2 in electrolysis mode, 80 h, 800 °C and H₂O to H₂ ratio of 70:30).     

Synthesis and characterization of Nanocrystalline Ba0·6Sr0·4Co0·8Fe0·2O3 for application as an efficient anode in solid oxide electrolyser cell

Nanocrystalline Ba_0·6Sr_0·4Co_0·8Fe_0·2O₃ (BSCF-6482) powder is synthesized by combustion synthesis technique. Powder calcined at 1000 °C reveals phase pure cubic perovskite. Transmission electron microscopic (TEM) analysis exhibits soft agglomerates of average size ∼50 nm wherein interplanar spacing for (110) and (221) resembles to the cubic lattice. While DC electrical conductivity of 23 S cm⁻¹@800 °C is observed, interfacial polarization measured by electrochemical impedance spectroscopy is found to be the least @850 °C (0.18 Ω cm²). Cell performance has been compared among BSCF-6482, BSCF-5582 and LSCF-6482 mixed ionic and electronic conducting (MIEC) and conventional electrode (LSM). Higher performance (1.37 A/cm²@1.3 V,800 °C) with high hydrogen generation rate (0.57 Nl/cm²/h) is found during steam electrolysis with cell fabricated using BSCF-6482 having minimal area specific resistance 0.33 Ω cm². Under similar operating condition, BSCF-5582, LSCF-6482 and LSM exhibit hydrogen generation rate of 0.35, 0.28 and 0.23 Nl/cm²/h respectively. Cell microstructure is clinically correlated with the higher reactivity of BSCF-6482 air electrode in steam electrolysis.     

Proton conductivity in stoichiometric and sub-stoichiometric yittrium doped SrCeO3 ceramic electrolytes

The crystal structure and electrical properties of stoichiometric perovskite proton conductors SrCe_1−xY_xO_3−δ (where x = 0.025, 0.05, 0.075, 0.1, 0.15, and 0.2 and δ = x/2) and substoichiometric Sr_0.995Ce_0.95Y_0.05O_3−δ have been investigated. The conductivities of the samples were measured as a function of the partial pressure of oxygen at 600 and 800 °C, and at two water vapor pressures (P_H2O=0.01 and 0.001 atm). A P_O2 range of 1 atm (pure O₂) to approximately 1 × 10⁻²⁵ atm (N₂/H₂ mix) allowed for the separation of n-(electron), p-(hole), and i-(ionic) type conductivities.In the case of stoichiometric perovskite proton conductors, the unit cell volume (UCV) and calculated density decrease with increasing yttrium content. The ionic and p-type components of the conductivity show threshold effect with Y-doping, which may be related to the double substitution of Y on both A- and B-sites. A maximum ionic conductivity of 5 mS/cm is found at 10% Y, whereas p-type conductivity increases with increasing yttrium concentration. A conductivity component appearing at low oxygen partial pressures decreases with yttrium doping. The substoichiometric material showed a drop in unit cell volume of approximately 0.34 Å³ compared to its stoichiometric partner. The conductivity components of substoichiometric material are higher than the conductivities of corresponding stoichiometric material, being approximately 7 mS/cm for both P_H2O levels.     

Synthesis and characterization of cobalt-free SrFe0·8Ti0·2O3-δ cathode powders synthesized through combustion method for solid oxide fuel cells

Cobalt-free SrFe_0·8Ti_0·2O_3-δ cathode powders were synthesized through the combustion method. Results of thermogravimetric and Fourier transform infrared analyses suggested that a perovskite oxide started to form at temperatures above 1100 °C. X-ray diffraction and Rietveld refinement analyses confirmed that the single-phase cubic structure (Pm-3m) of the SrFe_0·8Ti_0·2O_3-δ cathode was produced after calcination at 1300 °C. The average sizes of the particles were 1.0827 and 1.4438 μm as revealed by field emission scanning electron microscopy and dynamic light scattering analysis, respectively. In addition, energy dispersive X-ray analysis coupled with mapping revealed the homogeneous distribution of elements in the cathode. The thermal expansion coefficient of the SrFe_0·8Ti_0·2O_3-δ cathode is 16.20 × 10⁻⁶ K⁻¹. For the electrochemical behavior, the area specific resistance of cathode (0.60–13.57 Ω cm²) was obtained at 600–800 °C, and the activation energy was 121.77 kJ mol⁻¹. This work confirmed the potential of a SrFe_0·8Ti_0·2O_3-δ cathode in the intermediate temperature solid oxide fuel cell.     

Investigation on properties of BaZr0.6Hf0.2Y0.2O3-δ with sintering aids (ZnO,NiO, Li2O) and its application for hydrogen permeation

BaZr_0.8Y_0.2O_3-δ proton conductor has the characteristics of excellent chemical stability, but its impoverished sinterability and low conductivity hinder its applications in fuel cell and hydrogen separation. Hf doping in Zr site improves BaZr_0.6Hf_0.2Y_0.2O_3-δ sinterability and conductivity. To further enhance BaZr_0.6Hf_0.2Y_0.2O_3-δ properties, three kinds of sintering aids ZnO, NiO or Li₂O were introduced and their effect on the sinterability, microstructure and conductivity of BaZr_0.6Hf_0.2Y_0.2O_3-δ were studied. The experimental results display that 4 mol% ZnO can enhance the sinterability and conductivity of BaZr_0.6Hf_0.2Y_0.2O_3-δ sample sintered at 1400 °C. Compared with BaZr_0.6Hf_0.2Y_0.2O_3-δ sintered at 1600 °C, BaZr_0.6Hf_0.2Y_0.2O_3-δ with 4 mol% ZnO is of larger grain size, higher relative density (95.5%) and lower sintering temperature (reducing by 200 °C). Meanwhile, the conductivity of BaZr_0.6Hf_0.2Y_0.2O_3-δ with 4 mol% ZnO reaches 4.17 × 10^?3 S cm^?1 in wet 5% H₂/Ar at 700 °C, due to the reduction of the grain boundary resistance of sample. BaZr_0.6Hf_0.2Y_0.2O_3-δ with 4 mol% ZnO membrane for hydrogen separation via external short circuit was developed. The membrane with a thickness of 1.08 mm gives a hydrogen permeation flux of 0.098 mL min^?1cm^?2 at 800 °C with 50% H₂/He as feed gas. The presence of water vapor significantly promotes the hydrogen permeability of the membrane. In addition, introduction of 3% CO₂ or 100 ppm H₂S into feed gas does not decrease the hydrogen permeation flux of the membrane.     

Experimental evaluation and energy analysis of a two-step water splitting thermochemical cycle for solar hydrogen production based on La0.8Sr0.2CoO3-δ perovskite

A study of the hydrogen production by thermochemical water splitting with a commercial perovskite La_0.8Sr_0.2CoO_3-δ(denoted as LSC) under different temperature conditions is presented. The experiments revealed that high operational temperatures for the thermal reduction step (>1000 °C) implied a decrease in the hydrogen production with each consecutive cycle due to the formation of segregated phases of Co₃O₄. On the other hand, the experiments at lower thermal reduction operational temperatures indicated that the material had a stable behaviour with a hydrogen production of 15.8 cm³ STP/g_material·cycle during 20 consecutive cycles at 1000 °C, being negligible at 800 °C. This results comparable or even higher than the maximum values reported in literature for other perovskites (9.80–10.50 STP/g_material·cycle), but at considerable lower temperatures in the reduction step of the thermochemical cycle for the water splitting (1000 vs 1300–1400 °C). The LSC keeps the perovskite type structure after each thermochemical cycle, ensuring a stable and constant H₂ production. An energy and exergy evaluation of the cycle led to values of solar to fuel efficiency and exergy efficiency of 0.67 and 0.36 (as a percentage of 1), respectively, which are higher than those reported for other metal oxides redox pairs commonly found in the literature, being the reduction temperature remarkably lower. These facts point out to the LSC perovskite as a promising material for full-scale applications of solar hydrogen production with good cyclability and compatible with current concentrating solar power technology.     

BaCe0.85Tb0.05Co0.1O3−δ perovskite hollow fibre membranes for hydrogen/oxygen permeation

Co-doped BaCe_0.85Tb_0.05Co_0.1O_3−δ (BCTCo) nanopowder was synthesized via a sol–gel method using ethylenediaminetetraacetic acid (EDTA) and citric acid as the chelating agents. Using the resultant powder, BCTCo perovskite hollow fibre membranes were then fabricated by the combined phase inversion and sintering technique. Properties of the BCTCo powder and the hollow fibre membranes in terms of crystalline phase, morphology, electrical conductivity, porosity, mechanical strength and hydrogen/oxygen permeation were investigated by a variety of characterization methods. The results indicated that doping of cobalt in the BCTb oxide led to a higher electrical conductivity and lower calcination temperature for the powder precursor to a perovskite structure as well as sintering temperature for the hollow fibre precursors to gastight membranes. In order to obtain gastight and robust hollow fibre membranes, the sintering temperature should be controlled between 1300 and 1450 °C. The maximum hydrogen flux through the BCTCo hollow fibre membranes reached up to 0.385 mL cm⁻² min⁻¹ at 1000 °C under 50% H₂–He/N₂ gradient, which is higher than that of the un-doped BCTb hollow fibre membranes with the same effective thickness, and especially much higher than that obtained from other proton conductors due to the asymmetric structure of the membrane designed. Moreover, the BCTCo hollow fibre membrane also exhibited noticeable oxygen permeation fluxes, i.e. 0.122 mL cm⁻² min⁻¹ at 1000 °C under the air/He gradient. However, doping of cobalt might damage the mechanical stability of the perovskite membranes in the hydrogen-containing atmosphere.     

Experimental and DFT studies on catalytic reforming of acetic acid for hydrogen production over B-doped Co/Al2O3 catalysts

Steam reforming of bio-oil for hydrogen production is a promising green technology. Acetic acid was used as the bio-oil model compound. Experimental and density functional theory calculations were carried out to study the performance of Co/Al₂O₃ catalysts doped with boron (B) with a 1 wt.%–5 wt.% content. Catalyst characterization by BET, XRD, XPS, NH₃-TPD, H₂-TPR, TEM, and TG-DTG was performed. We found that the catalyst performance improved significantly by B doping. Under the reaction conditions of T = 500 °C, steam-to-carbon ratio (S/C) = 5, and liquid hourly space velocity (LHSV) = 4.3 h^?1, the catalyst with a B doping ratio of 1 wt.% had the highest hydrogen yield of 85% and a maximum acetic acid conversion rate of 95%. The corresponding hydrogen productivity was 0.8 mmol/min. The stability of this catalyst exceeded 29 h. Density functional theory calculations showed that the interactions between the reaction intermediates and the surface were strengthened with B addition.     

Indium doped niobium phosphates as intermediate temperature proton conductors

Indium doped niobium phosphates were prepared from precursors of trivalent indium oxide, pentavalent niobium oxide and phosphoric acid. The obtained materials were characterized by X-ray diffraction, impedance spectroscopy, FT-IR spectroscopy and scanning electron microscopy. It was found that the indium doping promoted formation of the cubic Nb₂P₄O₁₅ phase instead of the monoclinic Nb₅P₇O₃₀ phase in the pristine niobium phosphates and enhanced the preservation of OH functional groups in the phosphates. The preserved OH functionalities in the phosphates after the heat treatment at 650 °C contributed to the anhydrous proton conductivity. The Nb_0.9In_0.1 phosphate exhibited a proton conductivity of five times higher than that of the un-doped analog at 250 °C. The conductivity was stabilized at a level of above 0.02 S cm⁻¹ under dry atmosphere at 250 °C during the stability evaluation for 3 days.     

Ta-doped PrBaFe2O5+δ double perovskite as a high-performance electrode material for symmetrical solid oxide fuel cells

Symmetrical solid oxide fuel cells (S-SOFCs) have received considerable attention due to fewer preparation steps in recent years. The PrBaFe₂O_5+δ (PBF) is a candidate material due to good catalytic activity and electrochemical stability. In this work, Ta-substituted PBF materials (PrBaFe_2-xTa_xO_5+δ, denoted as PBFTx, x = 0, 0.1, 0.2, 0.3) are prepared and evaluated as symmetrical electrodes on GDC(Gd_0.1Ce_0.9O_2-δ)-YSZ(yttria-stabilized zirconia)-GDC three-layer electrolyte. The PrBaFe_1.8Ta_0.2O_5+δ (PBFT0.2) symmetrical cell presents the lowest polarization resistance, and the value is 0.171 Ω cm² and 0.503 Ω cm² in air and hydrogen atmosphere at 800 °C, respectively. In addition, the PBFT0.2 cell shows a peak power density of 234 mW/cm² using humidified hydrogen as fuel gas and air as oxidant at 800 °C, which is enhanced by 68% compared with that of PBF (138 mW/cm²). The results indicate that the strategy of Ta doping can improve the electrochemical performance of PBF and PBFT0.2 is a potential electrode for S-SOFCs.     

Improving the proton conductivity of sulfonated poly (ether ether ketone) membranes by incorporating a crystalline nanoassembly of trimesic acid and melamine

A novel proton exchange membrane was synthesized by embedding a crystalline which was nano-assembled through trimesic acid and melamine (TMA·M) into the matrix of the sulfonated poly (ether ether ketone) (SPEEK) to enhance the proton conductivity of the SPEEK membrane. Fourier transform infrared indicated that hydrogen bonds existed between SPEEK and TMA·M. XRD and SEM indicated that TMA·M was uniformly distributed within the matrix of SPEEK, and no phase separation occurred. Thermogravimetric analysis showed that this membrane could be applied as high temperature proton exchange membrane until 250 °C. The dimensional stability and mechanical properties of the composite membranes showed that the performance of the composite membranes is superior to that of the pristine SPEEK. Since TMA·M had a highly ordered nanostructure, and contained lots of hydrogen bonds and water molecules, the proton conductivity of the SPEEK/TMA·M-20% reached 0.00513 S cm⁻¹ at 25 °C and relative humidity 100%, which was 3 times more than the pristine SPEEK membrane, and achieved 0.00994 S cm⁻¹ at 120 °C.     

A high-performance cobalt-free Ruddlesden-Popper phase cathode La1·2Sr0·8Ni0·6Fe0·4O4+δ for low temperature proton-conducting solid oxide fuel cells

Ruddlesden-Popper typological (R-P type) layered material La₂NiO₄ is known for the excellent ionic conductivity and fast oxygen kinetics, but limited by its electronic conductivity as a single-phase cathode for low-temperature proton-conducting solid oxide fuel cells (LT H-SOFC). Cobalt-doping can improve the electro-catalytic capability, accompanied with an increased thermal expansion coefficient (TEC), which would lead to the delamination at the cathode/electrolyte interface. In this assignment, strontium and iron co-doped R-P phase cathode La_1·2Sr_0·8Ni_0·6Fe_0·4O_4+δ (LSNF), exhibiting fine oxygen conduction, sufficient electronic conductivity and compatible TEC with the electrolyte, is investigated thoroughly. The single cell with LSNF cathode based on BaZr_0·1Ce_0·7Y_0·2O_3-δ (BZCY) electrolyte achieves a maximum power density (MPD) of 781 mW cm⁻² with the low interfacial polarization resistance (R_p) of 0.078 Ω cm² at 700 °C. Interestingly, the single cell can also possess an eximious power output of 138.5 mW cm⁻² at relatively low temperature of 500 °C. Moreover, the excellent long-term stability with no observable performance degradation for almost 100 h at 600 °C could also indicate that the single-phase R-P layered material LSNF is a preeminent cathode candidate for LT H-SOFC.     

Preparation,electrical and thermal properties of new anode material based on Ca-doped perovskite CeAlO3

Tetragonal perovskite phase Ce_0.9Ca_0.1AlO_2.95 + x was obtained for the first time. Such phase, containing cerium in the oxidation state of 3+, can be promising anode materials for a solid oxide fuel cells (SOFCs). Ce_0.9Ca_0.1AlO_2.95 + х (space group I4/mcm) was synthesized by the solid-phase method at 1400°С in a nitrogen flow with using ammonium oxalate (NH₄)₂C₂O₄ to create a reducing atmosphere. Thermogravimetry results showed that Ce_0.9Ca_0.1AlO_2.95 + x was stable to oxidation up to 500°С in air and up to 700°С in argon (partial pressure of oxygen рО₂ = 10⁻⁴ bar). The thermal expansion coefficient measured by dilatometry was equal to 11.16·10⁻⁶ К⁻¹. The temperature dependences of the electrical conductivity (for undoped phase CeAlO₃ σ ≈ 1·10⁻³ S/cm and for doped Ce_0.9Ca_0.1AlO_2.95 + x σ ≈ 3·10⁻² S/cm at 500°С in air) were obtained by the electrochemical impedance spectroscopy measurements). The electrical conductivity of these samples at the temperatures range of 350–500°С was almost independent of the partial pressure of oxygen рО₂ from 10⁻¹⁸ to 0.21 bar, however, there was a slight negative slope at T > 500 °C (рО₂). The total ionic transport numbers measured by the EMF method were close to 1·10⁻³, which indicated the dominance of electronic conductivity. The measurement of the sign of the thermal-EMF showed that positive charge carriers (holes) were dominant charge carriers.     

Study of CaZr0.9In0.1O3−δ based reversible solid oxide cells with tubular electrode supported structure

In recent years, the Reversible Solid Oxide Cells (RSOCs) are regarded as direct energy converters between hydrogen and electricity. The proton conducting oxides proposed as electrolyte materials for RSOCs have several advantages. Perovskite type oxides CaZr_0.9In_0.1O_3-δ (CZI) are known as high temperature proton conductors with high chemical stability and mechanical properties. In this paper, Ni-CZI electrode supported tubular single cells with CZI thin film electrolyte are fabricated for the first time. Composite air electrodes with La_0.6Sr_0.4CoO₃ (LSC) nano-particles impregnated into porous CZI matrix are applied to improve the electrochemical performance. Three single cells with different LSC impregnation loadings are tested and compared. The modified single cell achieves hydrogen production rate of 2.1 mL·min^?1cm^?2 at 1.3 V and 850 °C. After the initial 18% performance degradation, the cell performance almost kept constant in 3 SOEC-SOFC cycles. All these results show the potential application of CZI materials and electrode supported tubular structure for RSOCs.