A highly active and synergistic Pt/Mo₂C/Al₂O₃ catalyst for water-gas shift reaction

Catalysts consisting of Pt and Cu supported on Mo₂C/η-Al₂O₃, Mo₂C/γ-Al₂O₃ or Mo₂C were prepared and used for the low-temperature water gas shift reaction (WGSR). The catalysts were characterized by elemental analysis, powder X-ray diffraction (XRD), temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The catalysts were studied in water gas shift reaction with a reaction mixture containing 11% CO, 43% H₂, 6% CO₂, 21% H₂O (real feed composition mixture from the reformer) and balance He, with a reaction temperature range of 180–300 °C at a space velocity (SV) of 125,000 h⁻¹. Catalyst supports (η-Al₂O₃ and γ-Al₂O₃), led to different synergetic effect between the two most active phases of Pt metal and Mo₂C. Pt/Mo₂C/η-Al₂O₃ is a promising catalyst (44% conversion at 180 °C) due to the close interaction between Pt and Mo₂C phases on the surface of the catalyst. The 4 wt% Pt-Mo₂C showed the highest activity where the temperature at which 50% conversion observed was at only 180 °C with SV of 125,000 h⁻¹ and constant stability over 85 h.