Aqueous-phase reforming of methanol, acetic acid, 4-methylcatechol, and phenol over supported nickel and platinum catalysts

The aqueous phase reforming of methanol, acetic acid, phenol, and 4-methylcatechol was studied to evaluate the potential of using process water from hydrothermal liquefaction of black liquor for hydrogen production. Various catalysts, including Cu- or Co-doped nickel and commercial Pt/AC, were tested under plug-flow conditions (230 °C, 32 bars). The platinum catalyst showed superior stability, maintaining high conversion with methanol and acetic acid. However, it showed no activity with phenol and deactivated rapidly when exposed to 4-methylcatechol. Doped nickel catalysts experienced severe deactivation, particularly with acetic acid and phenolic compounds. While nickel catalyst deactivated in the presence of acetic acid, Pt showed stable conversion but favored decarboxylation reaction. APR of methanol primarily produced H2 and CO2, with NiCu/γ-Al2O3 being the most selective for H2. Co-doped nickel favored hydrogenation, forming CH4 and thus reducing H2 yield. APR of phenol and 4-methylcatechol produced H2, CO2, and hydrodeoxygenated or hydrogenated liquid products.