Chemical-Looping Methane Hydrogen Production Performance of Cu, La, Ce Modified Fe2O3/Al2O3 Oxygen Carriers
Chemical looping methane steam reforming (CL-MSR) enables sequential production of high-selectivity syngas and high-purity hydrogen via redox cycling, yet single iron-based oxygen carriers suffer from poor cycling stability, low reactivity, and sintering. This study modified Fe2O3/Al2O3 oxygen carriers with Cu, La, and Ce additives via dip-coating, and systematically characterized their physicochemical properties, reactivity, and hydrogen production performance. Results showed that spinel-phase CuFe2O4 exhibited higher reactivity than perovskite LaFeO3 and CeO2, promoting deeper reduction of Fe2O3. Fe58Cu2Al achieved an oxygen storage capacity of 6.5 mmol/g. During CH4 reaction, Fe58Cu2Al exhibited the highest oxygen loss of 12.1 g/100 g oxygen carrier, with syngas yield of 5.15 mmol/g—1.33 and 1.59 times that of Fe60Al. In hydrogen production, the 2% Cu-modified carrier yielded 5.13 mmol/g H2, 1.51 times that of pristine Fe60Al, with purity exceeding 98%. After ten cycles, H2 yield remained at 3.61 mmol/g, surpassing the single-cycle output of pristine Fe60Al (3.39 mmol/g), demonstrating superior dispersion and coking resistance. The study establishes Cu modification as an effective strategy to enhance reactivity and cyclic stability of iron-based oxygen carriers for CL-MSR hydrogen production.