A mixed spinel oxygen carrier with both high reduction degree and redox stability for chemical looping H2 production

Abstract

Developing the oxygen carrier of high reduction degree and redox stability has key importance to the chemical looping hydrogen production. However, high reduction degree of oxygen carrier often leads to severe sintering and poor redox stability. Therefore, the trade-off between such two aspects of it must be considered. In this paper, a Co0·5Fe0·5(FeAl)Ox material was reported as an oxygen carrier and an investigation on the performance of its chemical looping hydrogen production was conducted. It exhibited a stable and high hydrogen yield of 8.53 mmol/g during 20 cycles even at the reduction degree of 0.75. Upon comparison, it was found that the obvious deactivation occurred in Fe2O3 material when its reduction degree was higher than 0.25. Upon various characterization techniques, we found that the high performance of such material was rightly because of the reversible exsolution and dissolution of its active compositions from and into the parent spinel support.