Effect of Calcination Temperature on the Perovskite Characteristics Prepared by Modified Pechini Method

Abstract

Perovskite type oxides which have the general formula as $ABO_3$ including both rare earth elements and 3d transition metals is gaininginterest according to be utilized as such strategic materials because of their excellent catalytic, magnetic, electrical and opticalproperties. Along with perovskitic materials, lanthanum nickel oxide ($LaNiO_3$-LNO) shows potential as a consequence of itselectronic and catalytic properties in not only reactions like reforming, redox reactions but also in storage and conversion of energy orsynthesis an electrode material. LNOs are widely prepared by methods like sol-gel, co-precipitation, solid state and Pechini. Amongthese methods, the Pechini method practices the metal salts consisting of nitrates, acetates, etc. as precursors and citric acid (CA) as achelating agent of metal ions and ethylene glycol (EG) utilized like a cross-linking agent to arrange a polymeric resin based onmolecular level and declines metal ions segregation and confirms compositional homogeneity. This process can defeat most of thedifficulties and disadvantages that frequently occur in the alkoxides related to sol−gel method. The study attempts to scan theinfluence of calcination temperature on the physical properties of $LaNiO_3$ catalysts prepared by modified Pechini method withoutethylene glycol. In order to lay out the physical properties, X-ray diffraction (XRD), scanning energy micoscopy (SEM), and $N_2$adsorption/desorption techniques were used. The change with the temperature in the structure caused a decline in specific surfacearea, pore volume and rise in pore size. XRD results showed that LNO calcinated at 700°C favored the establishment of an almosthomogeneous $LaNiO_3$ phase rather than calcination at 500°C. The study underlined that the preparation of the LNO by the modifiedPechini method can be applied successfully with the temperature above 700°C without EG as a cross-linking agent.