Sr, Mg co-doped LaGaO3-δ supported Fe2O3 improved the water gas shift reaction with chemical looping

Abstract

Fe2O3 is prospective for the chemical looping redox cycles but must contain a significant amount of inert supports to ensure high stability. The traditional inert supports (Al2O3, MgAl2O4, etc.) have a dilution effect on Fe2O3, which results in a compromised reactivity. In this work, we propose several Sr, Mg co-doped LaGaO3-δ to support Fe2O3 for chemical looping water splitting and investigated the synergy for the enhanced performance. Mechanistic study manifests that doping Sr increases the amount of oxygen vacancies, promoting the oxygen release and uptake during the redox reaction. Doping Mg mitigated the interaction between Fe2O3 and the supports, leading to much enhanced stability. Therefore, Fe2O3/La0.6Sr0.4Mg0.4Ga0.6O3-δ shows both high hydrogen yield (9.75 mmol.g−1) and peak hydrogen production rate (3.7 mmol.g−1.min−1). The performance shows only a slight decrease even after 100 cycles. The observed results can also inspire the selection and development of advanced supports to improve both the reactivity and stability of oxygen carriers.