Study on the effect of CeO2 on Fe2O3/LaNiO3 as the oxygen carrier applied in chemical-looping hydrogen generation

• Fe2O3/LaNiO3 manifested poor stability after the 58th cycle in CLHG.
• Fe2O3–CeO2/LaNiO3 gave steady H2 production during 100 cycles.
• CeFeO3 existed in Fe2O3–CeO2/LaNiO3 can increase the amount of lattice oxygen.

Fe2O3/LaNiO3, prepared by the citric acid complexation method and the impregnation method, was used as the oxygen carrier in Chemical-Looping Hydrogen Generation. The evaluation performance indicated that the oxygen carrier was sufficiently active that methane was totally oxidized, and the hydrogen yield was notably high at first. However, poor stability manifested as of the 58th cycle, dramatically reducing the CH4 conversion from 55 mL to 7 mL. The addition of CeO2 to Fe2O3/LaNiO3 as a promoter was tested and characterized by BET, SEM, TPR, XRD, Raman and XPS methods. Fe2O3–CeO2/LaNiO3 was evaluated under the same evaluation conditions as Fe2O3/LaNiO3. The evaluation performance indicated that Fe2O3–CeO2/LaNiO3 remained highly active even after 100 cycles. IR and XPS characterization illustrated that CeFeO3 was formed during the reduction–oxidization cycles. The oxygen carrier had good stability due to the formation of CeFeO3, which can increase the amount of lattice oxygen on the surface of the oxygen carrier.