Effect of Fe/Cu ratio on the activity of Fe–Al–Cu catalysts for water gas shift reaction under hydrogen-rich atmosphere

Catalysts with different Fe/Cu molar ratios were prepared by co-precipitation method and evaluated under hydrogen-rich atmosphere (H2 = 72.2 vol%). The effect of Fe/Cu ratio on the activity of Fe–Al–Cu catalysts for water gas shift reaction (WGSR) was investigated. The samples were characterized by X-ray diffraction (XRD), Temperature programmed reduction (TPR) and Brunauer–Emmett–Teller (BET) techniques. The results suggested that the optimal Fe/Cu ratio of Fe–Al–Cu catalyst was 1:1 and its highest CO conversion efficiency is 97.8% at 300 °C, excessive Cu resulted in poor catalytic activity. Fe–Al–Cu catalysts possessed a good activity at 250–550 °C and their CO conversions reached 87.3% and 84.6% at 250 °C and 550 °C, respectively, which is ascribed to the fact that copper not only acts as an active role for water gas shift reaction at 250 °C but also conducts as an electronic promoter in solid solution at higher temperature. Furthermore, magnetite had catalytic effect at higher temperature.