Chemical Looping with Oxygen Uncoupling (CLOU) which uses solids oxygen carrier providing gaseous oxygen for combustion is an effective technology for CO2 capture with low-energy penalty. Oxygen carrier is a cornerstone for CLOU, because stable and high rate of oxygen release must be assured. In this work, a refractory brick was attempted as support for Cu-based oxygen carrier due to its high crushing strength and agglomeration resistance. Samples of Cu25RefBri, Cu30RefBri and Cu40RefBri with 25-40wt.% CuO loadings were prepared via successive impregnation and then calcined at 800oC for 6h in air atmosphere. Decomposition-oxidation cycles were performed in a TGA apparatus and a batch fluidized bed reactor at temperatures of T=900-950oC. The Cu25RefBri showed the highest rate of oxygen release among the stated oxygen carrier samples. This material, however, showed decrease of reactivity in either TGA or fluidized bed tests, mainly attributable to the formation of low-active CuAl2O4 spinel. The stable rate of oxygen release from Cu25RefBri could be as low as 0.2∙10-4 kgO2/(s∙kgOC), while the stable O2 concentration can be decreased to 0.8vol.% at 900oC, which is much lower that the equilibrium value at this temperature. In combination of hard agglomeration found at oxidation stage under 950oC, the attempted Cu25RefBri could not be considered as a suitable oxygen carrier for CLOU.