We investigated NiFe₂O₄/Ce_0.9Gd_0.1O_1.95 (GDC) composites as oxygen carrier materials for chemical looping hydrogen production (CLHP). CLHP is a promising technology to simultaneously capture carbon dioxide and produce hydrogen from fossil fuels. We found that increasing GDC content increased the amount of the hydrogen production of NiFe₂O₄/GDC composites. Moreover, the oxygen transfer rate for the re-dox reaction increased significantly with increasing GDC content. GDC may affect the reaction kinetics of NiFe₂O₄/GDC composites. The finely dispersed GDC particles on the surface of NiFe₂O₄ can increase the surface adsorption of reaction gases due to the oxygen vacancies on the surface of GDC, and enlarge the active sites by suppressing the grain growth of NiFe₂O₄. The NiFe₂O₄/15wt% GDC composite showed no significant degradation in the oxygen transfer capacity and reaction rate during several re-dox cycles. The calculated amount of hydrogen production for the NiFe₂O₄/15wt% GDC composite would be 2,702 L/day per unit mass (kg).

Keywords: Chemical looping hydrogen production, oxygen carrier material, re-dox reaction, oxygen transfer capacity, oxygen transfer rate