Effect of Synthesis Route on Properties of CuO as a High Temperature Oxygen Carrier

Copper oxide powders intended for use as oxygen carriers in high temperature air separation and chemical looping combustion have been synthesized by a range of ceramic synthesis techniques including citrate gel, Pechini, precipitation, alanine assisted combustion, and high temperature oxidation. The evolution of morphology and crystal structure in the synthesis of powders was characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The surface chemical properties of the powders were studied using X-ray photoelectron spectroscopy (XPS). The oxygen sorptive/desorptive kinetics was studied using thermogravimetric analysis (TGA). Kinetics of the oxygen exchange reactions were analyzed and explained using empirical kinetics models with minimum error. A strong correlation was observed between the oxygen desorption parameters and oxygen to copper ratio calculated from measured XPS spectra. Copper oxide powders synthesized using the alanine assisted combustion and citrate gel methods resulted in optimum kinetic properties for use as an oxygen carrier at high temperature