Inverse ZrO2/Ni catalyst with interfacial electron transfer for hydrogenolysis of tetrahydrofurfuryl alcohol

Inverse oxide/metal catalysts have demonstrated remarkable interfacial electronic interactions, yet their design has been predominantly limited to oxides possessing intrinsic redox couples (e.g., Ce 4+ /Ce 3+ ). Whether interfacial electron transfer alone, in the absence of such a redox couple, can generate sufficient oxygen vacancies for catalytic C–O bond activation remains an open question. Herein, we report an inverse ZrO 2 /Ni catalyst, synthesized via a one-step NaOH coprecipitation method, in which electron transfer from the metallic Ni substrate drives Zr 4+ reduction and oxygen vacancy formation in ZrO 2 , a difficult-to-reduce oxide lacking an intrinsic redox couple. Systematic characterizations (TEM, XPS, Raman, H 2 -TPR) reveal that the inverse configuration increases the Zr 3+ content by 9.0 percentage points and raises the oxygen vacancy fraction from 29.3 % to 39.7 %, an increase of 10.4 percentage points, relative to conventional Ni/ZrO 2 . In the selective hydrogenolysis of tetrahydrofurfuryl alcohol (THFA) to 1,5-pentanediol (1,5-PDO), the inverse ZrO 2 /Ni catalyst achieves a 1,5-PDO yield of 67 %, 4.5-fold higher than the conventional counterpart (15 %), with a 23 kJ/mol lower apparent activation energy. Ex situ FT-IR spectroscopy indicates that the inverse catalyst strongly adsorbs THFA as an intact molecule via interaction with oxygen-vacancy-enriched ZrO 2 sites, whereas the conventional catalyst shows negligible adsorption. These findings demonstrate that interfacial electron transfer from a metal substrate can serve as an effective driving force for oxygen vacancy generation in difficult-to-reduce oxides, extending the inverse catalyst concept beyond intrinsically reducible systems and providing a noble-metal-free strategy for C–O bond hydrogenolysis.