Highly stable Fe/CeO2 catalyst for the reverse water gas shift reaction in the presence of H2S

Abstract

This study focused on evaluating the catalytic properties for the reverse water gas shift reaction (RWGS: CO₂ + H₂ → CO + H₂O ΔH⁰ = 42.1 kJ mol⁻¹) in the presence of hydrogen sulfide (H₂S) over a Fe/CeO₂ catalyst, commercial Cu–Zn catalyst for the WGS reaction (MDC-7), and Co–Mo catalyst for hydrocarbon desulfurization. The Fe/CeO₂ catalyst exhibited a relatively high catalytic activity to RWGS, compared to the commercial MDC-7 and Co–Mo catalysts. In addition, the Fe/CeO₂ catalyst showed stable performance in the RWGS environment that contained high concentrations of H₂S. The role of co-feeding H₂S was investigated over the Fe/CeO₂ catalyst by the temperature programmed reaction (TPR) of CO₂ and H₂ in the presence of H₂S. The result of TPR indicated that the co-feeding H₂S might enhance RWGS performance due to H₂S acting as the hydrogen source to reduce CO₂.