Porous Yttria-stabilized Zirconia Research Articles

Ni migration on porous yttria-stabilized zirconia and yttria-micropatterned fuel electrodes in solid oxide fuel cells

This study investigates the mechanism of Ni migration and methods for preventing Ni migration by utilizing ceramic obstacles that can block or slow Ni movement during solid oxide fuel cell (SOFC) operation. A patterned thin-Ni model anode on mirror-polished yttria-stabilized zirconia (YSZ) substrate exhibited dynamic movement during operation, as reported previously. In this study, we attempt to elucidate the mechanism of Ni migration that occurs only on the surface of solid-state Ni by blocking or slowing this movement using porous patterns of different materials. Porous micropatterns of 100 % YSZ and 80 wt% yttria (Y2O3) + YSZ composites were fabricated on a YSZ electrolyte, and velocity changes and blocking of Ni were observed. The porous YSZ structure changed the velocity of the Ni. In contrast, no Ni migration occurred in the Y2O3/YSZ composite porous structure, despite migration occurring in the neighboring smooth YSZ area in the same cell. The Ni-migrated areas were separated by the Y2O3/YSZ porous area, indicating that Ni migration was not caused by microscale differences in temperature or supplied gas diffusion, and Ni moved only on the cell surface, not via Ni-containing gases because temperatures and gases cannot form micropatterns.

Correction to: Microstructure Modifications to Enhance the Scattering Coefficient of Porous Yttria-Stabilized Zirconia Coatings

Correction to: Microstructure Modifications to Enhance the Scattering Coefficient of Porous Yttria-Stabilized Zirconia Coatings

Microstructure Modifications to Enhance the Scattering Coefficient of Porous Yttria-Stabilized Zirconia Coatings

Microstructure Modifications to Enhance the Scattering Coefficient of Porous Yttria-Stabilized Zirconia Coatings

Ultrafast-switching of an all-solid-state electric double layer transistor with a porous yttria-stabilized zirconia proton conductor and the application to neuromorphic computing

All-solid-state electric double layer transistors (ASS-EDLTs) have recently been attracting attention because of their huge potential for use in neuromorphic device applications. However, their low switching response speed is a significant drawback to their practical application. Here, we demonstrate ultrafast-switching of ASS-EDLTs, which was achieved by an excellent combination of hydrogenated diamond single crystal and a porous yttria stabilized zirconia thin film with extremely high proton conductivity. The switching response speed was investigated in response to gate voltage pulses. We achieved the ASS-EDLT that can operate at a very short response time of less than a hundred μs (i.e., 27 μs), even at room temperature. This is a far shorter time than that found in typical conventional ASS-EDLTs, which characteristically have response times measured in milliseconds or longer. Furthermore, the subject ASS-EDLT possessed characteristics that are similar to those of volatile memory devices. To demonstrate neuromorphic computing capability of the device, waveform transformation task has been performed. The results indicated that the ASS-EDLT, with its high operating speed, can contribute to the development of high-speed neuromorphic systems.

Microstructure and permeability of porous YSZ ceramics with aligned and gradient pore channels fabricated by freeze casting

Porous yttria-stabilized zirconia (YSZ) ceramics with aligned and gradient pore channels were fabricated by the unidirectional freezing of aqueous suspensions with distinct solid loadings under different sintering temperatures. The results indicate that the microstructure and response properties could be tailored by adjusting the solid loading and sintering temperature. The pore channel size increased with the increase of solid loading or the decrease of sintering temperature, regardless of microstructure changes in an individual sample. With increasing the solid loading and sintering temperature, the compressive strength (7.18–30.76 MPa) increased owing to the lower porosity of individual samples. The fabricated samples had increasing Darcian and non-Darcian constants along the freezing direction due to the enhanced pore size and open porosity. The Darcian and non-Darcian constants in this paper were in the range of 7.06 × 10−13 to 5.92 × 10−12 m2 and 1.66 × 10−7 to 8.83 × 10−7 m, respectively. These results are of practical value for the fabrication and optimization of porous ceramics in the applications of filters and membrane supports.

Optimizing infiltration parameters of nanostructured anode electrode in solid oxide fuel cells

This study focuses on the development and optimization of nanostructured anode electrodes for solid oxide fuel cells (SOFCs) by infiltration method. Ni (nickel) catalyst in the form of a nickel nitrate solution is infiltrated into porous YSZ (yttria stabilized zirconia) backbone fabricated by tape casting. Numerous electrolyte-supported cells are fabricated to investigate the effects of several significant infiltration fabrication parameters such as catalyst loading and infiltration sintering temperature. Conventional cell with screen printed Ni-YSZ anode is also fabricated for comparison. Electrochemical performances and microstructural properties of the cells are examined and evaluated. The best peak performance of 0.398 W/cm2 at 800 °C is obtained from the cell, which is infiltrated 9 times with 2 M solution followed by firing at 800 °C. The conventional cell, on the hand, exhibits only 0.174 W/cm2 under the same testing conditions in spite of the relatively higher Ni catalyst content in the anode. Furthermore, the optimized cell produces 0.169 W/cm2 maximum power density at 700 °C. The overall results reveal that nickel catalyst infiltration is a very effective method to improve the cell performance by providing increased number of electrochemical reaction zones within the anode electrode due to nanostructured nickel catalyst formed around the main YSZ phase.

Amperometric type NO2 sensor based on La0.75Sr0.25Cr0.5Fe0.5O3-δ-Bi2O3 sensing electrode prepared by self-demixing

Bi2O3 modified La0.75Sr0.25Cr0.5Fe0.5O3-δ (LSCF) composites have been successfully prepared by self-demixing and used as the sensing electrode (SE) of an amperometric NO2 sensor with yttria stabilized-zirconia (YSZ) electrolyte. The Bi2O3 modified LSCF composites were formed from precursor La0.75Sr0.25BixCr0.5Fe0.5O3+δ (x = 0, 5%, 10%, 20%, 30% and 40%) after calcining at 1200 °C. The particle size of LSCF was increased with the Bi2O3 content increasing. The YSZ porous framework structures were fabricated on YSZ to prolong TPB and the LSCF-xBi2O3-SE with porous structure was prepared on the porous YSZ backbone after calcining at 1000 °C. It is found that the sensors attached with LSCF-xBi2O3-SE are more sensitive to different concentrations of NO2 (25–300 ppm) than the LSCF-based sensor. Among them, LSCF-20% Bi2O3 based sensor exhibits the highest sensitivity (0.301 μA /ppm at 550 °C). The relationship between ΔIs and NO2 concentrations of the sensor varies linearly at a given temperature. Meanwhile, the sensor shows well anti-interference capability for co-existent gases.

Manufacturing and Thermal Shock Characterization of Porous Yttria Stabilized Zirconia for Hydrogen Energy Systems

Porous yttriastabilized zirconia (YSZ), in a composite with NiO, is widely used as a cermet electrode in solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs). Given cycles of high temperature in these energy devices, mechanical integrity of the porous YSZ is critical. Pore morphology, as well as properties of the ceramic, ultimately affect the mechanical properties of the cermet electrode. Here, we fabricated porous YSZ sheets via freezing of an aqueous slurry on a cold thermoelectric plate and quantified their flexural properties, both for as-fabricated samples and samples subjected to thermal shock at 200 °C to 500 °C. Results of this work have implications for the hydrogen economy and global decarbonization efforts, in particular for the manufacturing of SOFCs and SOECs.

Solution Combustion Synthesis, Characterization, Photocatalytic Activity and Electrochemical Studies of Yttrium Stabilised Zirconia (Zr0.72 Y0.28 O1.862) Nanopowder

Background: Yttria stabilized zirconia (YSZ) is an attractive material which exhibits a characteristic combination of physical and chemical properties of YSZ in terms of inertness, resistant to corrosion, high mechanical strength, thermal stability, chemical stability and photostability. Because of these properties and applications, it is very important to synthesize yttrium stabilized zirconia (YSZ) powder. Till date, various preparative techniques have been reported for the synthesis of high porous YSZ nano powders. However, special equipment, long time with multistep processing, high calcination temperature, small surface area and low product yield are the usual drawbacks of most of the methods. Therefore. Solution combustion method (SCS) method has been established for the synthesis of YSZ nanopowder with high surface area. Objective: The main objective of our present research work is to effectively synthesized the Yttrium stabilized zirconia (YSZ) Zr0.72 Y0.28 O1.862 nanopowder by solution combustion method using yttrium nitrate (Y(NO3)3.6H2O), zirconyl nitrate (ZrO(NO3)2.XH3O) as oxidizers and ethylenediamine tetra acetic acid (EDTA) as a fuel and the synthesized powder was used in the application of photodegradation of dyes. Methods: YSZ nanopowder was synthesized by using Solution combustion synthesis. Solution combustion synthesis (SCS) is a simple exothermic self-sustaining one step chemical reaction, which will produce a large number of pores in the oxide material and inhibit their agglomeration leading to a large specific surface area and small crystallite size of the resulting material. Results and Discussion: Powder X-ray diffraction (PXRD) revealed the formation of pure cubic phase of YSZ (Zr0.72 Y0.28 O1.862) nanopowder and the crystallite size of 15.4 nm was calculated by using Scherrer’s formula. The porous morphology of the product was observed by SEM images. BET surface area reveals that the relatively larger surface area of 87.17 m2g-1. TEM analysis revealed uniform particle size distribution with average particle sizes varying in the range of 20-100 nm. The UV-Vis DRS spectrum was used to calculate the absorption wavelength (339 nm) and the corresponding band gap (3.72 eV) using Tauc plot. The photoluminescence spectrum of YSZ nanopowder showed an emission peak at 339 nm. The photodegradation (decolourisation) of methylene blue (MB) dye was increased from 75-90% with increase in the concentration of YSZ photocatalyst from 100 mg to 400 mg due to availability of OH radicals in the presence of UV radiation. The electrochemical studies using cyclic voltammetry reveal a substantial increase in current density of YSZ electrode from 0.0001A to 0.0005A when compared with bare carbon electrode and the instantaneous rise in redox current for the YSZ electrodes from 0.0001A to 0.0005A with increasing scan rate from 10 mVs-1 to 90 mVs-1. Conclusion: In our reported work, we start a simple and rapid solution combustion synthetic approach to produce highly effective YSZ nanopowder using EDTA as organic fuel. Because of large surface area and small particle size of the YSZ nanopowder shows 85% of degradation of MB takes place in presence of UV light. In order to understand the electrochemical property of YSZ, the redox current measurement was carried out using cyclic voltametry and resulted that increase in redox current for the YSZ electrodes with increasing scan rate from 10 mVs-1 to 90 mVs-1.

An Investigation of the Electrochemical Activity of (Ba/Sr)FeO3-y Anodes

FeOx, SrFeO3-y (SF), and Ba0.5Sr0.5FeO3−y (BSF) were studied for application as fuel oxidation catalysts in solid oxide fuel cells (SOFC) anodes. Electrodes were prepared by impregnation into porous yttria-stabilized zirconia (YSZ), with La0.3Sr0.7TiO3−y (LST) added for electronic conductivity. The electrode impedances decreased dramatically upon addition of SF and BSF and much less when only SrO or FeOx were added. Temperature Programmed Desorption (TPD) of O2 from oxidized BSF showed O2 desorbing between 200 °C and 700 °C, while no O2 desorbed from Fe2O3 below 900 °C. The results, together with thermodynamic analysis, suggest that stabilization of Fe+4 in the perovskite lattice plays an important role in enhancing the catalytic activity of SF and BSF by providing access to a Fe3+/Fe4+ redox couple that can accept oxygen anions from the yttria-stabilized zirconia (YSZ) electrolyte. Oxygen is weakly bound to these sites facilitating its reaction with adsorbed H2.

Correction to: Porous yttria-stabilized zirconia ceramics with low thermal conductivity via a novel foam-gelcasting method

Correction to: Porous yttria-stabilized zirconia ceramics with low thermal conductivity via a novel foam-gelcasting method

Fracture properties of porous yttria-stabilized zirconia under micro-compression testing

Micro-compression tests were carried out on pillars of 60 μm in diameter, milled by plasma focused ion beam in porous Yttria-Stabilized Zirconia (YSZ) pellets. The fracture properties were determined over a wide range of porosities (33 %–63 %) for 8YSZ and at a given pore volume fraction of 63 % for 3YSZ. The mechanical properties determined from testing were reproducible thanks to the homogeneity of the microstructures. The Young’s modulus was estimated as a function of the porosity from the unloading curve of tests stopped before fracture. The experiments conducted until the total rupture allowed measuring the compressive fracture strength, which was found to decrease when increasing the porosity. Specimen tested and unloaded just before the total fracture were cross-sectioned by focused ion beam - scanning electron microscope. A transition was detected from a brittle behavior, with macro-cracks parallel to the direction of solicitation, to a diffuse damage with micro-cracks, when increasing the porosity.

Fracture of Porous Ceramics: Application to the Mechanical Degradation of Solid Oxide Cell During Redox Cycling

Solid Oxide Cell (SOC) is a high-temperature electrochemical device that can be operated in both fuel and electrolysis modes. It is constituted of a dense electrolyte in Yttria Stabilized Zirconia (YSZ) sandwiched between two porous electrodes. The hydrogen electrode is classically made of a cermet composed of Nickel and YSZ (Ni-YSZ). Because of system failures in operation (e.g. a fuel shortage or air re-introduction during the system shutdown), the Nickel is liable to be re-oxidized inducing its volume expansion. The Ni swelling within the cermet leads to a mechanical damage in the YSZ backbone [1] resulting in a degradation of the overall cell performances [2]. Therefore, it is still required to enhance the hydrogen electrode robustness for a higher redox tolerance. For this purpose, it is essential to predict accurately the formation and distribution of micro-cracks in the YSZ network during the re-oxidation. Nevertheless, the modeling of the initiation and propagation of cracks in complex microstructures of porous ceramics is still a subject of investigation. Moreover, there is also a lack of data on fracture properties for the porous YSZ material. In this frame, the present study was focused to propose a relevant model for the initiation and the growth of cracks in porous ceramics in order to simulate the fracture induced by Ni re-oxidation. For this purpose, a coupled experimental and modeling approach has been adopted (Fig.1). For the experimental part, the mechanical characterizations have been performed on thin YSZ membranes of different porosities representative of SOC microstructures. The compression test has been chosen as it generates a quasi-uniform stress field in the tested samples. To this end, micro-pillars of few tens of micro-meters in section have been milled in the YSZ membrane using a xenon plasma focused ion beam. For each investigated porosity, the compressive fracture strength has been measured on several pillars. The tested samples have been carefully characterized to assess the damage in the microstructure. As expected, the compressive strength was found to decrease with increasing the porosity. Moreover, a transition has been observed from a brittle behaviour at low porosity towards a local damage at high porosity [3]. All these experimental data have been used to validate a numerical tool to simulate the fracture in porous microstructure. In this study, a model based on the Phase Field Method (PFM) has been developed. In this approach, the crack is modeled implicitly through a smooth scalar damage variable and its width is controlled by a length scale parameter. Therefore, this method is well adapted to solve the fracture problem in complex and heterogeneous materials since it is mesh independent. The implemented model corresponds to the one proposed by C. Miehe et al. [4] who proposed a staggered scheme for the numerical resolution. A special attention has been paid in this work to evaluate the model capability to accurately predict the crack initiation for porous electrode material. For this purpose, the results of the PFM simulations have been compared to the mixed criterion proposed by D. Leguillon [5]. The study has been conducted on notched samples with different opening angles and for macro-cracks blunted by different cavity sizes. It has been highlighted that the two approaches provide consistent predictions for the crack initiation. Moreover, it has been checked that the PFM model is able to reproduce accurately the expected decrease of the fracture toughness when increasing the material porosity. Once these studies completed, the PFM model has been used to simulate the micro-compression test using a multiscale approach. It has been found that the model is able to reproduce correctly the decrease of the measured compressive fracture strength with the sample porosity. Moreover, the distribution of cracks in the simulations has enabled analysing the transition from a brittle to a local damage detected during the experiments. The validated model has been applied to simulate the fracture induced by the Ni re-oxidation. The repartition and density of micro-cracks in the YSZ backbone has been computed during the Ni reoxidation and the results have been confronted with an available tomographic data set. Finally, the impact on the cermet redox tolerance of the Yttrium content in YSZ has been discussed thanks to the modelling. [1] Faes, A. et al. J. Power Sources 193, 55–64. [2] Laurencin, J. et al. J. Power Sources 192, 344–352. [3] Meille, S. Et al . J. Eur. Ceram. Soc. 32, 3959–3967. [4] Miehe, C. et al. Comput. Methods Appl. Mech. Eng. 199, 2765–2778. [5] Leguillon, D. J. Mech. – A/Solids 21, 61–72. Figure 1

Additive Manufacturing for Rapid Prototyping of Mixed Potential Electrochemical Sensors

Natural gas pipeline leaks are responsible methane emissions that amount to over 1.6 x 108 metric tons of CO2 equivalent and more than 2 billion dollars in losses.[1, 2] A widely deployable sensor capable of remotely monitoring pipelines to promptly detect these leaks is needed to curb their environmental and economic impact. YSZ based mixed-potential electrochemical sensors (MPES) fit this need as they are cheap and durable, allowing for wide deployment in the field. Prototyping of these sensors is enhanced by the utilization of additive manufacturing (AM).The long lead times and high start-up cost of traditional ceramic manufacturing techniques are poorly suited to prototype development of mixed potential electrochemical sensors. Recent advances in AM techniques have opened the possibility for the rapid prototyping of these sensors.[3] We report for the first time a three element mixed potential electrochemical sensor manufactured using direct write syringe extrusion. La0.87Sr0.12CrO3 (LSCO), In2-xSnxO3 (ITO), Au and Pt electrodes bridged with a porous yttria-stabilized zirconia (YSZ) solid electrolyte have been deposited on YSZ substrates. The Pt electrode and leads, as well as the porous YSZ electrolyte and YSZ substrate are deposited by direct write extrusion. The printing parameters for the printing of the YSZ substrate are optimized to achieve desired surface and bulk material characteristics. A density 60% of theoretical of the YSZ substrate is obtained after sintering at 1450 C. The sensors are evaluated for their sensitivity to methane, ethane, ammonia, nitrous oxide, and hydrogen. The sensitivity of the sensors will be compared to that of an industry standard MidIR sensor for natural gas detection.[1] A.J. Marchese, T. L. Vaugh, D. J. Zimmerle, D. M. Martinez, L. L. Williams, A. L. Robinson, A. L. Mitchell, R. Subramanian, D. S. Tkacik, J. R. Roscioli, S. C. Herndon. Science. 7204 (2018).[2] Kort, E. A.; Frankenberg, C. Costigan, K.R.; Lindenmaier, R.; Dubey, M. K; Wunch, D. Geophys. Res. Lett, 2014, 41, 19, 6898[3] Travitzky, N., Bonet, A., Dermeik, B., Fey, T., Filbert‐Demut, I., Schlier, L., Schlordt, T. and Greil, P., 2014. Additive manufacturing of ceramic‐based materials. Advanced engineering materials, 16(6), pp.729-754.Figure 1. Additively manufactured three electrode pair mixed potential electrochemical sensor. Figure 1

Robocasting and surface functionalization with highly bioactive glass of ZrO2 scaffolds for load bearing applications

AbstractThis work is a proof of concept for making load bearing implants with osseointegration and bone bonding ability. Yttria‐stabilized zirconia (YSZ) scaffolds with a percentage of macro porosity of about 70% were fabricated by robocasting. Although a maximum solids volume fraction of 50 vol.% could be achieved, the 3D‐printing process revealed to be more reliable when using inks with 48 vol.% solids. The sintered porous structures exhibited an average compressive strength of ~236 MPa. After some preliminary coating experiments, an ethanol slurry of fine bioactive glass (BG) particles (10 wt.%) stabilized with polyvinylpyrrolidone was used to deposit a uniform surface coating onto the filaments, followed by glazing at 850°C. The functionalized scaffolds showed a relatively uniform surface coverage by the bioactive glass. The results of in vitro testing by immersing the scaffolds in simulated body fluid (SBF) showed remarkable morphological surface changes and an extensive deposition of hydroxyapatite layer. The overall results demonstrate the viability of producing porous YSZ scaffolds with excellent bioactivity, which are promising for bone tissue engineering under load bearing applications.

Effects of pyrolytic carbon on carburization strengthening and corrosion of 3YSZ hollow fiber membranes

Carbon species incorporation and carbon deposits are common in the manufacture process and application of yttria-stabilized zirconia (YSZ) ceramics, while the potential corrosion induced by the resultant carburization is unclear. The 3YSZ hollow fiber membranes were prepared by wet spinning method. A sintering procedure at 1300–1450 °C under 0.02 MPa oxygen partial pressure, and thereafter an oxidation treatment at 800 °C were applied to investigate the carbothermal reaction and carburization corrosion mechanism. It was found that the trace carbon species of 1.0–2.2 mol% derived from polymeric precursors triggered the carburizing strengthening of porous YSZ membranes without sacrificing porosity and deformability. However, the carburization corrosion also occurred at the mild oxidation treatment, resulting in deterioration in bending strength and integrated structure converting into fine grains. Raman spectra, XPS bands and HR-TEM images confirmed that the in-situ synthesized ZrCxOy oxidized into monoclinic ZrO2, and micro-cracking formed along grain boundaries, which led to substantial mechanical strength loss.

Control of the Pore Structure of Plasma-Sprayed Thermal Barrier Coatings through the Addition of Unmelted Porous YSZ Particles

In this study, a new pore structure control method for plasma-sprayed thermal barrier coatings (TBCs) through the addition of unmelted, porous yttria-stabilized zirconia (YSZ) particles was investigated. Through a unique way of feeding powder, two powder feeders were used simultaneously at different positions of the plasma flame to deposit a composite structure coating in which a conventional plasma-sprayed coating was used as a matrix and unmelted micro-agglomerated YSZ particles were dispersed in the dense conventional coating matrix as second-phase particles. The effects of the distribution and content of second-phase particles on the microstructure, mechanical properties, and lifetime were explored in a furnace cyclic test (24 h) of the composite coating. The mechanical properties and lifetime of the composite coating depend on the content and morphology of the particles embedded in the coating. The lifetime of the composite structure coatings is significantly higher than that of the conventional coatings. By adjusting the spraying parameters, the lifetime of the composite coating prepared under the optimum process is up to 145 days, which is about three times that of the conventional coating. The results of this study provide guidance for the preparation of high-performance composite structure TBCs.

Compression strength and fracture mechanism of a hierarchical porous yttria-stabilized zirconia microsphere prepared using electro-spraying associated with phase inversion technique

The compression strength and breakage mechanism of a hierarchical porous sphere in hundred-micron size were investigated in the present work. 3 mol% yttria-stabilized zirconia (YSZ) microspheres were prepared by electro-spraying associated with phase inversion (ES-PI) technique. The characteristic compression strengths of the ES-PI microspheres were measured by quasi-static uniaxial compression test, which increased from 19 MPa to 155 MPa as the sintering temperature increased from 1100 °C to 1400 °C. With the similar porosity, the compression strength of the hierarchical structure microsphere was almost three times higher than that of the hollow microsphere. Further, the breakage mechanism of the ES-PI microspheres was proposed by the honeycomb model of cellular materials, which suggested that the breakage of the ES-PI microsphere initiated from the elastic instability of the walls around the finger-like pores. These findings can help the mechanical performance optimization for ceramic microspheres with lightweight structure.

High-Performance, Thermal Cycling Stable, Coking-Tolerant Solid Oxide Fuel Cells with Nanostructured Electrodes.

Solid oxide fuel cells (SOFCs) are a promising solution to a sustainable energy future. However, cell performance and stability remain a challenge. Durable, nanostructured electrodes fabricated via a simple, cost-effective method are an effective way to address these problems. In this work, both the nanostructured PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) cathode and Ni-Ce0.8Sm0.2O1.9 (SDC) anode are fabricated on a porous yttria-stabilized zirconia (YSZ) backbone via solution infiltration. Symmetrical cells with a configuration of PBSCF|YSZ|PBSCF show a low interfacial polarization resistance of 0.03 Ω cm2 with minimal degradation at 700 °C for 600 h. Ni-SDC|YSZ|PBSCF single cells exhibit a peak power density of 0.62 W cm-2 at 650 °C operated on H2 with good thermal cycling stability for 110 h. Single cells also show excellent coking tolerance with stable operation on CH4 for over 120 h. This work offers a promising pathway toward the development of high-performance and durable SOFCs to be powered by natural gas.

Sealing of porous YSZ samples with Gd-doped CeO2 film produced using aqueous metal-EDTA complex solution

In this study, we propose a method for sealing porous samples using aqueous solutions of metal-ethylenediaminetetraacetic acid (EDTA) complexes. Gd-doped ceria (GDC) films were synthesized on porous NiO-mixed yttria-stabilized zirconia (YSZ) samples by coating them with a (Ce, Gd)-EDTA complex solution and subsequently sintering them in air at 850 °C for 1 h. When the Ce/Gd ratio in EDTA was 0.8:0.2, only a crystalline Ce0.8Gd0.2O1.9 phase was formed on the surface. The obtained results confirmed that the proposed treatment is effective for sealing the surfaces and open pores of porous samples. Finally, it was observed that a GDC layer was formed both at the sample surface and within the pores smaller than 1.7 μm.