Effect Of Iron On Durability Of Nickel-based Catalysts In Auto-thermal Reforming Of Ethanol For Hydrogen Production

摘要

Iron-promoted nickel-based catalysts were prepared by impregnation, tested in auto-thermal reforming (ATR) of ethanol for hydrogen production, and characterized by TPR, XRD, BET, TEM, and XPS. With the introduction of iron, mixed crystals of NiAl_2O_4-FeAl_2O_4 spinel phase are formed, which results in modifications of its structural and electronic properties. The reaction results show a remarkable improvement on durability in catalytic activity as well as selectivity to hydrogen in ATR: over the 10 wt.% iron-loading nickel catalyst, conversion of ethanol at 99.61% and selectivity of hydrogen around 115% are kept at 600 ℃ during a 30-h test, while that of iron-free sample decreases sharply from 85.10% to 19.71% on hydrogen selectivity within a 26-h test. The improved durability is attributed to the synergistic effect of the NiAl_2O_4-FeAl_2O_4 mixed crystals that are more resistant to sintering and oxidation in the oxidative atmosphere of ATR.