Development and performance of CeO2 supported BaCoO3−δ perovskite for chemical looping steam methane reforming

Chemical looping steam methane reforming (CL-SMR) is a promising approach to co-production of syngas and hydrogen, and the reactivity of oxygen carriers is crucial in the performance of CL-SMR. In this study, CeO 2 supported BaCoO 3-δ oxygen carriers with different component distributions (labeled as dry-mix, sol-gel, co-sol-gel samples) were prepared and evaluated in CL-SMR. The BaCoO 3-δ was loosely attached on CeO 2 in the dry-mix sample, resulting in a high resistance to oxygen mobility and a low gas production. The co-sol-gel sample possessed impurities of Co 3 O 4 , BaCO 3 and BaCeO 3 , which decreased reaction capacity and enhanced the secondary reaction of methane decomposition, leading to an excessive H 2 /CO ratio of syngas and coke formation. The contact of perovskite and CeO 2 in sol-gel sample favors the synergistic effect of perovskite and CeO 2, where the H 2 /CO ratio was close to the ideal value of 2 at 850 °C with the produced syngas and hydrogen reaching 4.57 mol/kg and 1.47 mol/kg, respectively. In situ Diffuse Reflectance Infrared Fourier Transform spectroscopy was employed to investigate the reaction mechanism of partial oxidation of methane, indicating that CH 4 is gradually dehydrogenated and partially oxidized by lattice oxygen, and the conversion of -O-CH 3 into -CHO and H 2 is the rate-controlling step. • CeO 2 /BaCoO 3-δ oxygen carriers with three different chemical distributions were prepared. • The uniform perovskite layer on CeO 2 support was essential for oxygen supply and reactivity. • A proper temperature could make a balance between reactivity and oxygen mobility. • The conversion of -O-CH 3 → –CHO is the rate controlling step in POM stage.