Solution Combustion Synthesis: Role of Oxidant to Fuel Ratio on Powder Properties

Abstract

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.

Physiochemical properties of combustion synthesized La0.6Sr0.4Co0.8Fe0.2O3− perovskite: A role of fuel to oxidant ratio

“…In SCS, type of fuel, fuel to oxidant ratio and ignition temperature determines the exothermicity of reaction and hence the final product [17,18]. Nevertheless, it would be difficult to draw any conclusion if all the parameters are varied simultaneously.…”

“…Nevertheless, the observed temperature is less than the adiabatic temperature as the reaction is not completely adiabatic but some part of heat is exchanged with its surrounding [18]. In addition, the above calculations are based upon the assumption that the reaction is initiated at 298 K. Fig.…”

Structural, morphological and electrical studies of BaCe0.8Y0.2O3-δ synthesized by solution combustion method

“…The gel was spontaneously ignited to form pale-yellow colored ash of oxide powder with some amount of impurities. The ash was collected and calcined at 900°C for 4 h to remove carbonbased impurities which were remained in the oxide powder [11]. This calcined powder was pelletized and sintered at 1300°C for 6 h.…”

Characterization of NiO–Al2O3 composite and its conductivity in biogas for solid oxide fuel cell

“…, and C 2 H 5 NO 2 (glycine) of analytical grade, all from Alfa Aesar were used. The stoichiometric composition of the redox mixture was calculated based on the principles of propellant chemistry, keeping the O/F ratio around unity [20]. The chemicals in required amounts were dissolved in double distilled water.…”