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Solution combustion synthesis technique is one of the novel techniques used to prepare nanoparticles, multi-component ceramic oxides and nanocomposites with properties better than conventionally prepared one and these materials have been used for various applications such as sensors, catalysts, and materials for solid oxide fuel cell (SOFCs). In the present work, the method has been used to prepare nanoparticles of 10 mol% Gd doped ceria (GDC) and Cu and its oxides. The oxidant to fuel (O/F) ratio is found to affect the powder properties and even compositional homogeneity. In glycine-nitrate combustion synthesis of GDC, as revealed by XRD studies, phase pure nanoparticles with crystallite size in the range 9-12nm were obtained for all the O/F ratios. TEM measurements of calcined powder showed hexagonal shaped particles of roughly 20nm size. The exothermicity was increased with the oxidant to fuel ratio resulting in high surface area and soft agglomerates. A slightly lean O/F ratio gives surface area of 73 m2/g and soft agglomerates (D50= 5.34 mm), which eventually results into high sintering density at low temperature. Raman Spectra of GDC showed a sharp and intense peak at 467 cm−1which corresponds to CeO2due to F2gsymmetry of the cubic phase. In combustion synthesis of copper nitrate and citirc acid, the compositional homogenity and phase purity was affected by the oxidant to fuel ratio. The combustion at stoichiometric O/F ratio gives Cu nano particles, lean O/F ratio gives nanoparticles of Cu, CuO and Cu2O and rich ratio gives pure CuO nanoparticles. These nanoparticles have been studied with different characterization techniques like XRD, TG-DTA, SEM, TEM, FT-IR and Raman.

High temperature co-electrolysis of steam and CO2 based on solid oxide electrolysis cell (SOEC) to produce syngas as a feedstock for the well-known Fischer-Tropsch process is the main aim of the present research. Here Ni-8YSZ/8YSZ/LSCF6428-GDC button cells have been fabricated and the effect of the different microstructural parameters like air electrode thicknesses, fuel electrode porosities, adhesion layer and thermodynamic parameters like gas composition, temperature, on the performance of SOEC has been investigated systematically. The SOEC with 10 μm air electrode thickness, functional layer, fuel electrode having 20 vol% PMMA content, addition of YSZ-GDC adhesion layer gives the better performance in overall results and the voltage obtained for this SOEC at current density of 0.8 A.cm−2 is ∼1.25 V at 800°C in 49% N2, 5% H2, 23% CO2 and 23% H2O gas mixture at fuel electrode side. To identify the electrochemical processes occurring at the electrodes of SOEC, distribution function of relaxation time (DRT) analysis of the electrochemical impedance (EIS) data is carried out.

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