Activity of Fe supported by Ce1−xSmxO2−δ derived from metal complex decomposition toward the steam reforming of toluene as biomass tar model compound

Ceria (CeO2) and samaria doped ceria (Ce1−xSmxO2−δ) powders with various Ce/Sm ratios have been successfully prepared via metal complex decomposition. The catalytic activities of these synthesized materials toward the steam reforming of toluene as model compound of biomass tar were studied with an aim to determine the suitable catalyst for biomass tar decomposition in biomass gasification system. From the study, H2, CO, CO2, CH4, C2H4 and C2H6 were the main products from the reaction with low carbon deposition observed on the catalyst surface after 18 h operation. Among all catalysts, relatively higher toluene conversion and H2 yield (32.8%) with greater resistance toward carbon deposition was achieved from Ce0.85Sm0.15O2−δ. To enhance better toluene conversion and H2 yield, Ce0.85Sm0.15O2−δ was further applied as the catalyst support by impregnating low-cost Fe on its surface; and its reforming activity was compared to Ni and Fe supported over conventional γ-Al2O3. It was found that, Fe/Ce0.85Sm0.15O2−δ offered significantly higher toluene conversion and H2 yield than Fe/Al2O3 (55.2% H2 yield compared to 16.5%). Its reforming activity was also comparable to Ni/Al2O3 with better H2 yield stability after 72 h operation (16% deactivation for Fe/Ce0.85Sm0.15O2−δ compared to 35% deactivation for Ni/Al2O3). Therefore, Fe/Ce0.85Sm0.15O2−δ has good potential to replace Ni-based catalyst in biomass gasification system.