Advances in catalysts for production of renewable H₂/CH₄ by Aqueous Phase Reforming (APR) of biomass-derived oxygenates

Aqueous phase reforming (APR) of biomass-derived oxygenates has emerged as a versatile and sustainable route for producing renewable hydrogen (H₂) and methane (CH₄) under relatively mild conditions (200–300 °C and 1.5–5 MPa). This review highlights recent progress in understanding and optimizing APR, with particular attention to catalyst development, reaction mechanisms, and process design strategies that influence product selectivity. Model compounds such as methanol, ethanol, ethylene glycol, and glycerol serve as representative substrates to probe the complex network of dehydrogenation, C–C and C–O bond scission, water-gas shift (WGS), and methanation reactions. Advances in catalyst design, ranging from noble metals (e.g., Pt, Pd) paired with oxygen-vacancy-rich or hydroxylated/acidic/basic supports, to non-noble systems (e.g., Ni–Sn, Ni–Cu, N-doped carbons), are discussed in terms of their ability to tune the H₂/CH₄ production. While certain catalysts promote reforming and WGS to favor hydrogen, others bias the route toward methanation, revealing the catalyst as a key variable for this reaction, in addition to the influence of conditions such as pressure and temperature. Finally, the identified challenges and outlined future directions highlight the potential of APR as a flexible and scalable technique for renewable fuel production, enabling on-demand tuning between green hydrogen and renewable natural gas.