Variable temperature structural study of Ca1-xSrxMnO3-d perovskites for use in chemical looping

CaMnO3-based perovskite oxides show promise as solid oxygen carriers for use in chemical looping. Partial substitution with small amounts of Sr increases both the capacity and lowers the onset temperature of oxygen release. The goal of the experiments is to investigate the crystal structure of two Ca1-xSrxMnO3-d compositions between 500-1000 C and monitor the release and uptake of oxygen in-situ. The onset of oxygen release is close to reported structural changes for samples studied in closed capillary conditions (i.e. without change in oxygen content). This study will provide valuable insight into the link between structure and oxygen storage capacity, which will aid the design of improved materials.