Yittria-stabilized Zirconia Research Articles

Tensile testing of Yttria-stabilized zirconia ceramic tapes for solid oxide cells

High temperature solid oxide cells (SOCs) play an important role in the worldwide green energy transition due to the high efficiency and great flexibility. For the cost and efficiency optimization of electrolyte-supported SOCs, a crucial property is the mechanical stability of the cell, which is mainly provided by the electrolyte. In this study, the authors investigate the tensile mechanical properties of 3% yittria-stabilized zirconia (3YSZ) ceramic electrolyte tapes, allowing the evaluation of a large material volume compared to the flexural test. A novel gripping system for misalignment minimization is developed. The sample machining is found to have an influence on the strength, as ground samples have an average strength above 1000 MPa, while the laser cut ones show strengths below 500 MPa. The influence of edge roughness and phase transformation during grinding is determined and the crack initiation point is examined.

Electrochemical Characterization of Pd-Based Catalysts Deposited on Yittria Stabilized Zirconia Solid Electrolyte for Methane Oxidation Reaction

Methane, the main constituent of natural gas, has received increased attention since it has a higher energy density than other fossil fuels while producing less particulates containing sulphur and nitrogen. However, although methane emits less CO2 than other fossil fuels, it has 28 times more global warming potential [1]. Therefore, complete methane oxidation via heterogeneous catalysis that prevents escaping unburned methane from the engine exhaust is a key solution to this issue.Palladium is the most effective conventional noble metal for methane catalytic oxidation, which is susceptible to deactivation, especially in the presence of water. The stability and activity of a monometallic Pd catalyst could be improved upon adding a second less expensive and more abundant non-noble metal or metal oxide[2]. The interaction of Pd nanoparticles and the second metal can be characterized using electrochemical means to understand the catalytic and electrocatalytic activity of catalysts[3,4].In this work, the electrochemical behaviour of PdM (M= Co, Sn, Fe and ZnO) nanoparticles deposited on YSZ solid electrolyte was evaluated for complete methane oxidation and compared to free-standing Pd catalyst. To this end, the nanoparticles were synthesized via the polyol method and tested for their open circuit catalytic oxidation and electrochemical performance in a temperature range from 320 to 400 °C under reducing, stoichiometric and oxidizing reaction conditions.The light-off experiments in open circuit condition revealed that the presence of Sn increased the catalytic rate of the reaction more than two other metals, Co and Fe, which resulted in lowering the reaction rate per unit mass of active catalyst. Furthermore, ZnO-supported Pd demonstrated the highest catalytic reactivity due to metal-support interactions. Lastly, the results demonstrate a higher level of catalytic reactivity with higher temperatures and oxygen partial pressures (pO2).Using Tafel plot calculations from the linear sweep voltammetry measurements, the exchange current density (io) was obtained for each catalyst, as well as the apparent activation energy of the reaction in the individual condition. It was found that higher exchange current density corresponds to lower open circuit catalytic rates.The catalyst was characterized thoroughly by several physicochemical techniques, such as TEM, SEM, XRD and ICP-MS.

Oxidation and Hot Corrosion Behavior of Thermal Barrier Coatings-A Brief Review

Oxidation and hot corrosion occur on metallic parts of gas turbines on account of exposure to high temperature. Thermal barrier coatings (TBCs) are used to protect gas turbine components made of Ni-based superalloys from high temperature oxidation as well as hot corrosion. The stability of coated metallic gas turbine components is higher than that of non-coated ones. Suitable coating is crucial for obtaining higher turbine inlet temperature. However, the problem of conventional TBC system is the failure of yittria-stabilized zirconia (YSZ) top coat due to formation of thermally grown oxide (TGO) layer between the bond coat and YSZ top coat. The TGO formation should be properly controlled in order to prevent the spallation of the top coat. In the current review paper, an attempt has been made to focus oxidation and hot corrosion behavior of conventional thermal barrier coatings applied on gas turbine components for increasing the efficiency of gas turbines.

SO2 Gas Sensor Based on LATP Solid Electrolyte

The emission of SO2 mainly comes from the burning of fossil fuels such coal and sulfur-containing oil. Thus, the source of SO2 emission may be contributed from power plants or steel making factories.Exposures to SO2 can harm the human respiratory system and make breathing difficult. People suffered by asthma are sensitive to these effects of SO2. To improve air quality, the concentration of SO2 is typically limited by national and/or regional standards to reduce emissions of SO2. Therefore, the accurate detection of SO2 is important. Electrochemical solid state sensors are known to provide reliable and stable signals based on the use of solid electrolytes. Oxygen sensors based on oxygen-conducting yittria-stabilized zirconia have shown their wide applications. In this study, a solid state SO2 sensor are developed using Li-conducting Li1.3Al0.3Ti1.7(PO4)3 (LATP). Li2SO4 is used as electrode. With the application of adequate voltage, Li2SO4 may be formed at the surface exposed to SO2-containing atmosphere. Thus, the current measured from the sensors is expected to be proportional to the concentration of SO2. The dependence of SO2 concentration, temperature, and electrode microstructure will be analyzed and discussed.

Effect Of Pressure On Density, Porosity And Flexural Strength During Cold Isostatic Press Of Alumina-Ysz-Chromia Cutting Tool

This study presented the effect of pressure on the density, porosity and flexural strength when cold isostatic press (CIP) was applied to compact the ceramic powders in the form of insert cutting tools. Specific composition of alumina (Al2O3) wt.90%, yittria stabilized zirconia (YSZ) wt.10%, chromium oxide(Cr2O3) wt.0.6% and polyethylene glycol (PEG) wt.0.6% were ball milled and hand pressed to form green body of ceramic inserts. These green body were undergone further compaction inside CIP with pressures variation of 200 MPa, 300 MPa, 400 MPa with 30 seconds and 60 seconds pressuring time. The ceramic composts were then sintered at 1440°C for 9 hours before being assessed with density, porosity, Rockwell hardness (HRC) and bending test. The results show that CIP use with 300 MPa parameters with 60 seconds shows the best mechanical properties with relative density 95.5%, porosity 4.5% and HRC 65.5 hardness. Further assessment of microstructure revealed that the particles size distributed evenly along fracture surface with coarse grain and porosity dominant in the certain area.

A Zn-Doped Ba0.5Sr0.5Co0.8Fe0.2O3-δ Perovskite Cathode with Enhanced ORR Catalytic Activity for SOFCs

The insufficient oxygen reduction reaction activity of cathode materials is one of the main obstacles to decreasing the operating temperature of solid oxide fuel cells (SOFCs). Here, we report a Zn-doped perovskite oxide Ba0.5Sr0.5(Co0.8Fe0.2)0.96Zn0.04O3-δ (BSCFZ) as the SOFC cathode, which exhibits much higher electrocatalytical activity than Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) for the oxygen reduction reaction (ORR). The BSCFZ cathode exhibited a polarization resistance of only 0.23 and 0.03 Ω·cm2 on a symmetrical cell at 600 and 750 °C, respectively. The corresponding maximum power density of 0.58 W·cm−2 was obtained in the yittria-stabilized zirconia (YSZ)-based anode-supported single cell at 750 °C, an increase by 35% in comparison to the BSCF cathode. The enhanced performance can be attributed to a better balance of oxygen vacancies, surface electron transfer and ionic mobility as promoted by the low valence Zn2+ doping. This work proves that Zn-doping is a highly effective strategy to further enhance the ORR electrocatalytic activity of state-of-the-art Ba0.5Sr0.5Co0.8Fe0.2O3-δ cathode material for intermediate temperature SOFCs.

Barium-Promoted Ruthenium Catalysts on Yittria-Stabilized Zirconia Supports for Ammonia Synthesis

The cost-effective, small-scale, distributed synthesis of ammonia depends on effective catalysts and processes that operate under modest elevated pressure (i.e., p < 20 bar) conditions. The present paper considers Ru as the active catalyst supported on yittria-stabilized zirconia (YSZ). The addition of alkali and alkaline-earth metal promoters is found to increase synthesis rates by an order of magnitude. The rate enhancement is largely insensitive to the promoter concentration, with Cs outperforming Ba and K by a factor of 2. However, Ba is found to be stable whereas Cs degrades more rapidly, which is attributed to the low melting point of its oxide. At 400 °C and 1.0 MPa, the specific synthesis rate over Ba–Ru is measured to be approximately 1410 mmol gRu–1 h–1, higher than the most active oxide-supported Ru catalysts reported in the literature. The rate becomes inhibited by H2 absorption at low temperature (below 350 °C), but lower H2/N2 ratios enable the rate to remain comparable to what is observed i...

Relationship between mechanical properties and microstructure of yttria stabilized zirconia ceramics densified by spark plasma sintering

Porous ceramics are widely used for many applications such as filters, insulators, electrodes for SOFC, membranes or bone scaffolds, with porosity in the typically range of 20–50%vol. The functionality of those materials comes at the expense of the degradation of their mechanical properties which are highly impacted by the rate, distribution, shape and size of the porosity. Among them tetragonal stabilized zirconia (TSZ) is one of the most industrially used; it is sometime called: “the ceramic steel” since in its dense state it exhibits the highest toughness for ceramics. It is known that the porosity has a huge impact on the thermo-mechanical properties of refractory ceramics as Yittria Stabilized Zirconia (YSZ). This study aims to capitalize the mechanical properties as a function of porosity to provide future applications and ensure the behavior in service of thermal barrier coating.In the present paper, the correlation between the microstructure and the mechanical properties such as Young modulus, hardness and strength of YSZ ceramics obtained by Spark Plasma Sintering (SPS) was investigated. Two types of YSZ powder, a nanometric one from Tosoh and a micrometric one obtained by sol-gel route were studied to prepare homogeneous mesoporous or oriented macroporous microstructure by partial sintering. SPS parameters have been determined and optimized to manage the porosity rate. Furthermore, a bimodal microstructure can be obtained, by mixing both powders, allowing the formation of linking bridges between the microporous zone and the nanopowder during sintering. The macroporous ceramics have lower Young modulus, hardness and strength than mesoporous ones. These characteristics are discussed in the paper taking into account the differences between microstructure and contacts between particles with various form factors. Thus, it is clearly evidenced that the morphology of raw powders and the level of porosity are key parameters to optimize the mechanical properties of such porous material.

Performance and Durability Evaluation for Anode-Supported Solid Oxide Fuel Cell with Ce0.8Sm0.2O2−δ - SmBa0.5Sr0.5Co2O5+δ Composite Cathodes

We synthesize the SmBa0.5Sr0.5Co2O5+δ (SBSC) powders by glycine nitrate combustion method and then design the composite cathodes by mixing with Sm0.2Ce0.8O2-δ (SDC) for thermal expansion mismatch concern. The cell exhibits good adhesion between layers to improve cell performance. The cell with yittria-stabilized zirconia (YSZ) electrolyte via cathode design of SDC | SDC-SBSC, is operated from 600 to 800 °C. The power densities for operation potential 0.7 V shows the acceptable value of 498 mWcm-2 at 800 °C. To evaluate the durability, it is operated under fixed current density over thousand hours. A slight degradation in the activation region can be observed at the initial stage. The degradation rate is estimated at less than 0.5 %/khr after activation with current loading. The operational conditions with lower current loading and higher operation potential are the solution to prolong the cell life time. Further demonstration for IT-SOFC cell product shall be executed.

Performance of Hybrid Powder-Suspension Axial Plasma Sprayed Al2O3-YSZ Coatings in Bovine Serum Solution.

Ceramic coatings on metallic implants are a promising alternative to conventional implants due to their ability to offer superior wear resistance. The present work investigates the sliding wear behavior under bovine serum solution and indentation crack growth resistance of four coatings, namely (1) conventional powder-derived alumina coating (Ap), (2) suspension-derived alumina coating (As), (3) composite Al2O3—20wt % Yittria stabilized Zirconia (YSZ) coating (AsYs) deposited using a mixed suspension, and (4) powder Al2O3—suspension YSZ hybrid composite coating ApYs developed by axial feeding plasma spraying, respectively. The indentation crack growth resistance of the hybrid coating was superior due to the inclusion of distributed fine YSZ particles along with coarser alumina splats. Enhanced wear resistance was observed for the powder derived Ap and the hybrid ApYs coatings, whereas the suspension sprayed As and AsYs coatings significantly deteriorated due to extensive pitting.

Performance and emission characteristics analysis of thermal barrier coated diesel engine using palm biodiesel

Various research works are being undertaken around the world on the subject of thermal efficiency improvisation and emission reduction from diesel engines. This research work analyzes the performance and emission characteristics of a thermal barrier coated diesel engine which used palm biodiesel. The piston and cylinder liners were coated with equal percentages of alumina (Al2O3) and yittria-stabilized zirconia (YSZ) powder using plasma spraying coating method. The piston was coated with 100μm thickness and the two cylinder liners were coated with 150 and 200μm thicknesses and were used to analyze the performance and emission characteristics. Test results of the thermal barrier coated engine using palm biodiesel were compared with the results derived from the base engine. The tests revealed an increase of 3.8% specific fuel consumption (SFC) as an average when neat palm biodiesel was used in the base engine. Interestingly, the palm biodiesel used in the 150- and 200-μm thick thermal barrier coated engine was responsible for a significant decrease of the SFC by an average of 4.18% and 8.05% respectively. The brake thermal efficiency was found to decrease on an average of 1.02% when tests were run using the neat palm biodiesel in the base engine. But an average proportionate increase of 0.72% and 2.19% was visible when palm biodiesel was used in the tests conducted on the 150- and 200-μm thick thermal barrier coated engine. There was also an understandable brake specific reduction of 0.991g/kWh carbon monoxide (CO) emission and 0.025g/kWh unburned hydrocarbon (HC) levels. The nitrogen oxide (NOx) emission was observed as 14.06g/kWh in the 200-μm thick thermal barrier coated engine which was slightly higher when the results were compared with that of the uncoated engine. The novelty of this research investigation is based on the usage of yttrium-stabilized zirconia and alumina thermal barrier coating on the cylinder liner and piston head of engine. This is justified due to the fact that most of the previous investigations undertaken focused on the thermal barrier coating in the piston, valve, and cylinder head alone. The utility factor of the palm biodiesel (B 100) in the low heat rejection engine has also proved to be another significant and novel factor in the present investigation outlined in this paper. This is mainly due to the fact that the ongoing investigations in this realm concentrated only on blends of 20 to 30% of palm biodiesel with diesel fuel in the low heat rejection diesel engine.

Performance and Emission Characteristics of Diesel Engine Using Thermal Barrier Coated Cylinder Liner and Piston

Improvement in thermal efficiency and reduction in emission from diesel engines are major thrust research work in all around the world. This research work is on the performance and emission characteristics of diesel engine using Low Heat Rejection (LHR) techniques of thermal barrier coated cylinder liner and piston. A piston was coated as 100 micron thickness and three cylinder liners were coated in the thickness of 100,150 and 200 micron. Piston and cylinder liners were coated with equal percentages of Alumina and Yittria Stabilized Zirconia powder using the plasma spraying coating method. The test results compared with base engine showed reduction in the performance parameter of specific fuel consumption (SFC) on an average by 6.11%, 12.78% and 16.89%, while the brake thermal efficiency increased by 1.68%,3.75% and 5.19% in 100,150 and 200 micron thickness coated cylinder liner used engine respectively. There was reduction in Carbon monoxide (CO), unburned hydrocarbon (HC) and smoke emissions levels while Nitrogen Oxide (NOx) emission was slightly higher in the coated engine compared with the uncoated engine in all load conditions. Overall, 200 microns thickness coated cylinder liner showed a better performance parameter and low emission compared with other cylinder liner coated engine.

Oxidation Behavior of NiCr/YSZ Thermal Barrier Coatings (TBCs)

Abstract Nichrome (NiCr) coatings are widely used to provide resistance against oxidation and corrosion in many machine components. TBCs must include bond coatings that are resistant to oxidation resulting fromhigh-temperature operating conditions. In the present study, NiCr powders were sprayed on nickel-based superalloy Inconel 718 substrates using atmospheric plasma spray (APS) technique. Bond-coated substrates were coated with yittria stabilized zirconia (YSZ). As such, the TBC samples were kept at 1000°C for 8 h, 24 h and 50 h in high temperature furnace and their isothermal oxidation behavior was investigated. Microstructure and phase change properties of TBCs before and after isothermal oxidation were then studied and analyzed.

Tri-doped ceria (M0.2Ce0.8O2-δ, M= Sm0.1, Ca0.05, Gd0.05) electrolyte for hydrogen and ethanol-based fuel cells

In recent scientific research, an interest has been gained significantly by rare earth metals such as cerium (Ce), samarium (Sm) and gadolinium (Gd) due to their use in fuel cells as electrolyte and catalysts. When used in an electrolyte, these materials lower the fuel cell's operating temperature compared to a conventional electrolyte, for example, yittria-stabilized zirconia (YSZ) which operates at a high temperature (≥800 °C). In this paper, the tri-doped ceria, M0.2Ce0.8O2-δ (M = Sm0.1, Ca0.05, Gd0.05) electrolyte powders was synthesized using the co-precipitation method at 80 °C. These dopants were used for CeO2 with a total molar ratio of 1 M. Dry-pressed powder technique was used to make fuel cell pellets from the powder and placed them in the furnace to sinter at 700 °C for 60 min. Electrical conductivity of such a pellet in air was 1.2 × 10−2 S cm−1 at 700 °C measured by the ProboStat-NorECs setup. The crystal structure was determined with the help of X-ray diffraction (XRD), which showed that all the dopants were successfully doped in CeO2. Raman spectroscopy and UV-VIS spectroscopy were also carried out to analyse the molecular vibrations and absorbance, respectively. The maximum open-circuit voltages (OCVs) for hydrogen and ethanol fuelled at 550 °C were observed to be 0.89 V and 0.71 V with power densities 314 mW cm−2 and 52.8 mW cm−2, respectively.

High speed moderate depth grinding of alumina and yittria stabilized zirconia

Material removal in low speed ceramic grinding is primarily due to micro-brittle fracture. High speed grinding of ceramics reduces micro-brittle fracture, but the main challenge to restrict the surface and sub-surface damage remains intact. In this work, alumina and yittria stabilized zirconia (YSZ) were ground using single layer electroplated diamond grinding wheels at wheel speed up to 200 m/s under conventional flood cooling environment. Wheel downfeed and work speed were kept constant. Grinding forces were monitored, morphology of the ground surfaces was investigated and surface roughness was measured across and along grinding directions. Surface residual stresses were measured using sin2ψ method of X-ray diffraction. Results indicated that micro-brittle fracture got substantially reduced at high wheel speed. A transition from brittle fracture to ductile flow was observed for alumina as the wheel speed was increased beyond 120 m/s. The ratio of average surface roughness values across and along the grinding directions was in good agreement with morphological observations. High wheel speed reduced grain fracture and surface crack density for alumina and YSZ, respectively. Compressive residual stresses were generated for alumina and YSZ, and were found to be in good correlation with normal grinding force. Overall, high speed grinding yielded better surface characteristics.

Epitaxial Growth of Baddeleyite NbON Thin Films on Yttria-stabilized Zirconia by Pulsed Laser Deposition

Baddeleyite niobium oxynitride (NbON) is a possible low-cost alternative to baddeleyite TaON, which is a well-known oxynitride semiconductor with high photocatalytic activity for visible light. In this study, baddeleyite NbON thin films were epitaxially grown on yittria-stabilized zirconia (YSZ) (100) substrates by using nitrogen-plasma-assisted pulsed laser deposition. Low temperature growth at 500 °C on a thin self-seed layer, which was deposited at 600 °C, was key to obtain baddeleyite NbON with almost stoichiometric chemical composition. X-ray diffraction measurement revealed multiple domain structure of the film with an epitaxial relationship of (100)NbON//(100)YSZ and [001]NbON//[001]YSZ. Band gap of the baddeleyite NbON films was 2.3 eV, which is smaller than that of baddeleyite TaON (2.5 eV). The NbON films showed n-type conduction with rather low mobility of 1.6 × 10−3 cm2 V−1 s−1, which is probably attributable to high defect density and grain boundaries.

Constitutive modelling and Weibull statistical analysis for the porosity - Mechanical property correlations in 3% yittria-stabilized zirconia system

The study set out to investigate the effect of porosity on the mechanical properties (e.g., hardness and elastic modulus) for a popular structural ceramic composition (as reference), viz., 3% yttria stabilized tetragonal zirconia (3YTZ) depicted the best fit against a second order polynomial decay pattern [equation of the type: M=M0 (1−c1P+c2P2)]. This is in contrary to the existing models where mostly an exponential decay pattern is noted. The possible reason has been assigned to an error analysis measure (σe) for the goodness of fit of the constitutive equations; a factor not given much importance during in earlier calculations. Weibull data analyses of the modulus and hardness data pointed out that the degradation rate is much higher for specific tests, e.g., compression testing compared to tests on a smaller scale (hardness). The mechanical properties and their rate of degradation were comparable up to the relative density of 70% of the volume fraction of porosity. The decay relationship of mechanical properties is expected to serve as a guide for future modelling and simulation purposes linking other systems, in general.

Conductivity of Yittria-Stabilized Zirconia Nanostructure Electrolyte for Solid Oxide Fuel Cell Application by Using RF Magnetron Sputtering

Yttria-stabilized zirconia (YSZ) thin films were deposited successfully using RF magnetron sputtering. The substrate had been used are sapphire glass. A pure ceramic of Zr-Y is synthesized and processed into a planar magnetron target which is reactively sputtered with an Argon-Oxygen gas mixture to form Zr-Y-O nanostructure. The aim of this research is to study the conductivity and roughness YSZ thin film by using RF magnetron sputtering by varying the temperature deposition parameter. By lowering the YSZ thin film into nanostructure would enable for SOFC to be operate at lower temperature below 400°C. The YSZ nanostructure were controlled by varying the deposition parameters, including the deposition temperature and the substrate used. The crystalline of YSZ structure at 100W and temperature 300°C. The surface morphology of the films proved that at 300°C temperature rate deposition showed optimum growth morphology and density of YSZ thin films. Besides, the high deposition subtrate temperature affected the thickness of YSZ thin film at 80nm by using surface profiler. A higher rate of deposition is achievable when the sputtering mode of the Zr-Y target is metallic as opposed to oxide. YSZ is synthesizing to obtain the optimum thin film for SOFC application.

Fabrication of Metal-Supported Solid Oxide Fuel Cells by Sinter-Joining Method with Silver Bonding Layer

Solid oxide fuel cell (SOFC) is an energy conversion device which generates electricity from hydrogen. SOFC is attracting attentions because of its high energy conversion efficiency and low material cost. For these reasons, SOFC are widely studied to be applied to various power generation systems such as stationary power plant, residential power system, auxiliary power unit (APU), etc. For APU applications, high mechanical strength is required to endure mechanical vibration and external shock during the driving of vehicles, which makes ceramic-based SOFC unsuitable. To overcome this limitation, metal-supported SOFC has been proposed. Metal-supported SOFCs are composed of metal substrate which supports ceramic layers of anode, electrolyte, and cathode. For more than past ten years, various types of metal-supported SOFC have been developed in many organizations. However, conventional metal-supported SOFCs had limitations of high cost thin film coating process such as sputtering, plasma spray, etc, sintering at reducing atmosphere, and unsintered cathode. In our research group, metal-supported SOFCs fabricated by sinter-joining method were developed. To fabricate metal-supported SOFCs by sinter-joining method, metal substrates were bonded to conventional ceramic cells by bonding paste composed of mixture of stainless steel, nickel oxide, yittria-stabilized zirconia (YSZ). Recently, silver has been proposed as bonding materials. By using silver as bonding materials, bonding of ceramic cell can be performed at temperature lower than 950 °C at air atmosphere, which enables full sintering of cathode. This has been rarely reported because conventional metal-supported SOFCs were fabricated by sintering at reducing atmosphere to prevent oxidation of metal substrate during the sintering. Furthermore, it is believed that electrical conductivity, thermal conductivity are improved, leading to lower ohmic resistance and better temperature distribution of metal-supported cells. In this work, 5 x 5 cm2 metal-supported SOFCs with silver bonding layer was successfully fabricated. The microstructure of bonding layer was investigated, which showed good adhesion of silver bonding layer. Electrochemical performance and impedance spectra were studied. Power density of 433 mW/cm2, ohmic resistance of 0.52 Ω cm2, polarization resistance of 0.16 Ω cm2 at 800 °C were obtained, and it is believed that high power density was attributed to low polarization resistance by full sintering of cathode. Metal-supported SOFCs fabricated by sinter-joining method showed 10 times higher mechanical strength than conventional ceramic cells.

Electrochemical Performance of Infiltrated Cu-GDC and Cu-PDC Cathode for CO2 Electrolysis in a Solid Oxide Cell

Solid oxide cells are fabricated by utilizing infiltration technique to impregnate: Cu-gadolinium doped ceria (GDC) and Cu-praseodymium doped ceria (PDC) electrodes in yittria stabilized zirconia (YSZ) scaffold. Electrochemical performance of the cell is measured for CO2 electrolysis in presence of H2 gas. The polarization resistances of the cell with Cu-PDC cathode are measured to be of relatively lower value 17.9 Ω cm2 and 5.1 Ω cm2 as compared to the corresponding 23.8 Ω cm2 and 7.5 Ω cm2 on Cu-GDC electrode for CO2/H2 ratio of 92/08 and 28/82 respectively. Similarly, CO2 electrolysis current on Cu-PDC cathode are measured relatively higher to the values of -0.056 A cm-2 at CO2/H2 = 76/24, -0.069 A cm-2 at CO2/H2 = 56/44 and -0.075 A cm-2 at CO2/H2 = 38/62. Impedance spectra of Cu-PDC cell at varying potential, indicated a significant decrease in polarization resistance from 17.9 Ω cm2 to 6.3 Ω cm2 as the applied potential increased from OCV (-0.89 V) to -1.6 V at CO2/H2=92/08. Thus, the experimental results suggested an improved electrocatalytic activity of Cu-PDC cathode as compared to Cu-GDC electrode, which is further improved on increasing the H2 concentration in the feed.