Highly efficient hydrogenolysis of tetrahydrofurfuryl alcohol to 1,5-pentanediol over a Ni–Co–La₂O₂CO₃ mixed oxide catalyst

1,5-Pentanediol (1,5-PDO) is a promising bio-based monomer with potential applications in polymers, coatings, and plasticizers, offering a sustainable alternative to petroleum-derived diols such as 1,6-hexanediol. In this study, we report a highly efficient catalyst based on a Ni–Co–La₂O₂CO₃ mixed oxide system for the hydrogenolysis of tetrahydrofurfuryl alcohol (THFA) to 1,5-PDO. A remarkable productivity of 8.9 mmol_1,5–PDO g_cat⁻¹ h⁻¹ was achieved under solvent-free conditions, representing the highest value reported to date for non-noble metal catalysts. Through detailed characterization and reactivity studies, the catalyst formulation and pretreatment were optimized to enhance performance. The system includes coordinatively unsaturated Ni²⁺ and Co²⁺ species, associated with oxygen vacancies (Ni²⁺/OV, Co²⁺/OV) and Brønsted-basic La₂O₂CO₃. Ni²⁺/OV sites promote hydrogen activation and facilitate oxygen vacancy (OV) formation in CoO at lower activation temperatures without degrading the La₂O₂CO₃ structure. Brønsted basic La₂O₂CO₃ sites promote hydroxyl-group deprotonation, generating alkoxide species that adsorb on Co²⁺/OV Lewis acid sites through both the ring oxygen and the alkoxide oxygen, thereby facilitating C2–O1 bond activation. Additionally, competitive adsorption between organic solvents and THFA was observed, limiting access to active sites. Solvent-free operation effectively eliminates this competition, improving THFA interaction with the catalyst surface and thereby boosting catalytic performance. These findings highlight the potential of rare-earth-based mixed oxides for the sustainable and scalable production of bio-derived diols.