Inhibited grain growth to strengthen the redox performance of CuFe2O4 via SiO2 as a support for the chemical looping gasification

Abstract

The inert component is an important part of the oxygen carrier in the chemical looping gasification. In this study, a variety of characterization analyses were conducted to investigate a role of SiO2 in crystal structure, morphology, pore structure during multiple cycles of CuFe2O4/SiO2 oxygen carrier. It was shown that CuFe2O4 presented an excellent cycle stability. During cycles, the inert component SiO2 always keeps the same phase, and the active component CuFe2O4 is the continuous loss and gain of lattice oxygen. There are not change much in elemental composition of CuFe2O4 during multiple cycles. Inert component SiO2 inhibiting the loss of copper during multiple cycles that obtained from the SEM analyses. Combined with the Zener effect, it is found that the inert component SiO2 as second-phase particles in the boundary between the CuFe2O4 grains to be inhibited the growth of the CuFe2O4 grains, which would be maintain the integrity of the oxygen carrier microwave structure. This can be strengthen cycle stability in the chemical looping gasification. Therefore, SiO2 with zener pinning effect would be well the cycle stability of the oxygen carrier.