In situ hydrogenation of bio-oil was performed using the bifunctional nickel-based industrial catalyst RZ409 without external hydrogen

Catalytic hydrogenation of bio-oil is a key strategy for producing high-quality biofuels. However, this process requires substantial external hydrogen—a scarce and energy-intensive resource. Bio-oil contains abundant acetic acid and water, making aqueous-phase reforming (APR) of these components a promising route to generate hydrogen in situ for upgrading other oxygenated compounds. This study evaluated the bifunctional nickel-based industrial catalyst RZ409 against Pd/C as a benchmark in a batch reactor for in situ bio-oil hydrogenation. We investigated APR-driven hydrogen generation, in situ hydrogenation performance, oil quality improvement, and reaction pathways—including esterification, hydrogenation, hydrodeoxygenation (HDO), and isomerization. Results show that RZ409 yielded higher residual H₂ (0.03 ± 0.01 mol) than Pd/C (0.02 ± 0.01 mol); reduced oxygen content by 24% versus 20.7%; increased higher heating value (HHV) by 13 MJ kg −1 versus 10 MJ kg −1 ; achieved hydrogen balances of 90.41 ± 5.49% (RZ409) and 91.61 ± 4.81% (Pd/C); and delivered carbon efficiencies of 42.93 ± 0.59% (RZ409) and 35.44 ± 0.47% (Pd/C). Catalyst properties were characterized by TGA, FTIR, H₂-TPR, NH₃-TPD, CO 2 -TPD, XRD, XPS, and TEM. This work demonstrates the feasibility of external hydrogen free in situ hydrogenation using RZ409—providing a practical pathway to reduce bio-oil upgrading's dependence on external H₂.