Influence of pH On Synthesis of Homogeneous Cobalt-Doped Barium Cerium Zirconium Oxide Via Oxalate Co-Precipitation

Objective of the research is to develop a homogeneous, high-temperature, bi-functional, electro-ceramic catalyst for simultaneous hydrogen generation from methanol and hydrogen purification by mixed protonic electronic conductivity. Aliovalent cation-doped barium cerates are known to display significant protonic conductivity at elevated temperatures under hydrogen containing atmospheres. Zirconium substitution is expected to improve chemical stability of the material and cobalt doping is expected to impart protonic and electronic conductivity to the material in addition to catalytic activity towards hydrogen generation reactions. Precursor for cobalt-doped barium cerium zirconium oxide was synthesized via the route of co-precipitation using metal nitrates as starting compounds and oxalic acid as precipitant. Final oxide is obtained by calcining the precursor at high temperature. Synthesis experiments were carried out under different pH values in aqueous medium and at a fixed temperature. Filtrate and precipitate samples were subjected to elemental analysis to understand the influence of reaction pH on the degree of precipitation of the four metals from solution.