Recyclable RANEY® Ni-catalyzed hydrogen reduction for green and efficient production of V₂O₃ from a vanadium-rich...

V₂O₃ is an important raw material for vanadium alloys. Compared to conventional calcination-reduction methods, hydrogen reduction offers a greener route for V₂O₃ preparation by avoiding ammonia-nitrogen wastewater and shortening processing time. However, hydrogen reduction typically suffers from low hydrogen reactivity. To address these issues, RANEY® Ni was introduced as a recyclable catalyst for hydrogen reduction. Under optimal vanadium precipitation conditions: RANEY® Ni dosage of 10 g L^-1, H₂ partial pressure of 3 MPa, temperature of 250 °C, pH of 5, and a reaction time of 100 minutes, the precipitation rate reached 99.84%. After magnetic separation, the V₂O₃ product achieved a purity of 99.16%, with a RANEY® Ni recovery rate of 96.01%. Characterization by BET, SEM-EDS, XRD, and H₂-TPD indicated that RANEY® Ni provides abundant active hydrogen adsorption sites and that partial vanadium deposition on the catalyst surface reduces surface area but does not significantly impair catalytic performance. After five cycles of hydrogen reduction, the V₂O₃ purity remained stably above 99.0%. RANEY® Ni maintained excellent stability and catalytic activity, thus confirming the technical feasibility of the hydrogen reduction process for V₂O₃ production.