Unveiling the role of Ni-Re catalyst on diverse supports for efficient hydrogenation of levulinic acid to γ-valerolactone under near atmospheric H2 pressure

The catalytic hydrogenation of levulinic acid to the important biomass-derived platform chemical γ-valerolactone was examined systematically under near-atmospheric H 2 pressure using a set of bimetallic Ni-Re catalysts supported on TiO 2 , MCM-41, Al 2 O 3 , ZSM-5, and MgAl hydrotalcite. Catalysts were prepared by an incipient wetness impregnation and were thoroughly characterized by comprehensive methods. Among the catalysts studied, Ni-Re/MgAl performed the best with 100 % conversion of LA and 95 % yield of GVL at 200 °C, 2 h, and 1 bar H 2 . The enhanced catalytic performance was ascribed to the combined effect of Re and Ni metals together with the distinctive properties of the MgAl support, which facilitated H 2 adsorption capacity, strengthened metal-support interactions, and provided significant acidity. Systematic kinetic studies asserted pseudo-first-order kinetics with the maximum rate constant ( k = 0.0119 min −1 ) for Ni-Re/MgAl. The impact of support properties on reducibility of metals, acidity, particle size, and reaction mechanism was described. The catalyst demonstrated very high activity under low-hydrogen pressure. The results validate the key role played by the support–metal interaction in maximizing bifunctional catalytic systems towards the valorization of biomass under mild conditions. • Ni-Re/MgAl catalyst shows highest LA conversion and GVL yield under mild H 2 pressure. • Support significantly affects metal dispersion, reducibility, and acidity. • Bimetallic Ni-Re system promotes hydrogen spillover and bifunctional synergy. • Pseudo-first-order kinetics observed with highest k for Ni-Re/MgAl catalyst. • Catalyst deactivation due to changes in catalyst structure as confirmed after reuse cycles.