Enhancing the performance of spinel La-doped CoFe2O4 oxygen carriers for chemical looping hydrogen generation

Abstract

Chemical-looping hydrogen generation (CLHG) is a clean and efficient method for sustainable hydrogen production. The industrial advancement of the CLHG technology hinges on the development of highly active and selective oxygen carriers (OCs). In this study, the performances of three spinel OCs (ZnFe₂O₄, CoFe₂O₄, and NiFe₂O₄) were investigated in a fixed-bed reactor. CoFe₂O₄ demonstrated the best reactivity and highest hydrogen yield. In addition, doping CoFe₂O₄ with varying amounts of La further improved its performance. The highest hydrogen yield (393 mL/g) was observed for CoFe₂O₄ doped with 10% by mass of La. The characterization results indicated that La not only facilitated the formation of oxygen vacancies but also accelerated lattice oxygen transfer. Furthermore, an optimized La doping level was found to boost the crystallinity of the oxygen carrier, leading to improved cycling performance. The insights gained from probing the performance of La-doped CoFe₂O₄ OCs are expected to contribute to the development of novel OCs for scaled-up CLHG technology.