Valorization of Bio-Oil Aqueous Fractions Through Oxidative Steam Reforming over Co/CeO2-SBA-15 Catalysts: From Single Model Compounds to Complex Mixtures

This study investigates the oxidative steam reforming (OSR) of simulated bio-oil aqueous fractions using Co/CeO₂-SBA-15 catalysts. Five representative compounds-methanol, acetic acid, hydroxyacetone, phenol, and furfural-were evaluated to assess their reactivity for hydrogen production. Aliphatic compounds achieved nearly complete conversion and stable hydrogen yields, while aromatic structures led to lower conversion and higher coke formation. Furfural exhibited higher reactivity than phenol due to its furan ring and aldehyde group. Catalysts with 10 and 20 wt.% Ce showed similar activity, but Co/20CeO₂-SBA-15 presented lower hydrogen yield. For this reason, next experiments of OSR of model compound mixtures were carried out only with Co/10CeO₂-SBA-15. To approach real bio-oil complexity, ternary and quinary mixtures were tested. High conversion and hydrogen yield were maintained over 50 h when the ternary mixture (methanol, hydroxyacetone, and acetic acid) was fed. When the quinary mixture was used as feedstock, which includes furfural and phenol, lower conversions were obtained for these compounds compared to aliphatic ones, although conversions remained above 80% after 50 h (88.9% for furfural and 82.6% for phenol). These results highlight Co/10CeO₂-SBA-15 as a viable catalyst for bio-oil aqueous fraction valorization under OSR conditions.