Fe2O3/CaO-Al2O3 multifunctional catalyst for hydrogen production by sorption-enhanced chemical looping reforming of ethanol.

Sorption-enhanced chemical looping reforming of ethanol for hydrogen production was investigated using Fe₂O₃ as oxygen carrier and modified CaO-based Al₂O₃ as CO₂ sorbent. Combined Fe₂O₃/CaO-Al₂O₃ multifunctional catalysts were demonstrated and prepared by different methods including sol-gel, mechanical mixing, and impregnation at different Fe contents (5, 10, and 15 wt%). The results showed that the multifunctional catalyst prepared by impregnation method with 5 wt% Fe loading provided the highest H₂ purity of 70% in the pre-breakthrough period which lasted for 60 min at 600 °C. This was attributed to the preserving of Ca₁₂Al₁₄O₃₃ inert support in the structure during the preparation as shown by XRD results, leading to higher surface area as determined by N₂ physisorption and to prevention of particle agglomeration as evidenced by SEM-EDX. Although the H₂ production was inhibited by the presence of Ca₂Fe₂O₅ phase, a stable performance was found for at least 5 repeated cycles both for sorption capacity and oxygen carrier. The ease of decarbonation was also observed with this material as confirmed by DSC-TGA analysis. This highlighted the mutual advantages of Fe in CaO sorption stability and Ca in Fe oxygen carrier stability which could offset their intrinsic weak robustness. [ABSTRACT FROM AUTHOR]