Fig. 5: Redox cycling of oxygen storage materials in a TGA.

a Weight change over 100 cycles of O2 release (CuO to Cu2O) under N2 of CuMgAl-MMO-LS. b weight change profile during O2 release under N2. Three typical samples were tested: CuAl-MMO, CuMgAl-MMO-LS (low strength), and CuMgAl-MMO-HS (high strength). The tests were performed in the TGA at 900 °C. c O2 release capacity over 100 cycles of O2 release. d XRD patterns of CuMgAl-MMO-LS at different states; e CuAl-MMO in different redox states.