Comparison of Pd–Ni–Mg/Ceria–Zirconia and Pt–Ni–Mg/Ceria–Zirconia Catalysts for Syngas Production via Low Temperature Reforming of Model Biogas

Low temperature dry reforming of methane was studied over (0.13–0.51 wt%) Pd and (0.16–0.64 wt%) Pt doped 1.4 wt%Ni–1.0 wt%Mg catalysts on a ceria–zirconia oxide support, as well as control catalysts containing Pt or Pd, but not Ni and Mg. Temperature-programmed reduction studies showed Pd catalysts having initial reduction peaks at lower temperatures compared to Pt catalysts. Reaction studies showed the lowest 10 % conversion of methane at 383 °C for the 0.13%Pd–1.39%Ni–1.0%Mg/(Ce 0.6 Zr 0.4 )O 2 catalyst. The same catalyst also had the lowest 10 % conversion temperature (366 °C) for carbon dioxide. Syngas ratios (H 2 :CO) for Pd catalysts (0.24–0.41) were better than Pt catalysts (0.22–0.30) at 450 °C, however still not close to the stoichiometric ratio as a result of the RWGS reaction simultaneously occurring at the low operating temperatures studied. Turnover frequencies were calculated from steady-state reaction experiments done in the temperature range of 430–470 °C. Both catalysts’ TOFs increased with increasing temperature, however overall Pt catalysts had marginally higher TOFs (2.69–4.74 s −1 ) compared to Pd catalysts (2.40–4.58 s −1 ). Although both Pd and Pt catalysts had comparable activities and rates, the 0.13 %Pd–1.39 %Ni–1.0 %Mg/(Ce 0.6 Zr 0.4 )O 2 catalyst was selected as the most promising one because of its higher H 2 :CO ratios, negligible changes during reaction as evidenced in post-reaction characterization, more basic sites that may decrease coking, and its lower cost.