Direct Catalytic Transformation of Biomass Derivatives into Biofuel Component γ-Valerolactone with Magnetic Nickel-Zirconium Nanoparticles.

A series of mixed oxide nanoparticles were prepared by a coprecipitation method and characterized by many techniques. Nickel-zirconium oxide catalysts and their partially reduced magnetic counterparts were highly efficient in the direct transformation of biomass derivatives, including ethyl levulinate, fructose, glucose, cellobiose, and carboxymethyl cellulose, into γ-valerolactone (GVL) without the use of an external hydrogen source, producing a maximum GVL yield of 95.2 % at 200 °C for 3 h with hydrogen-reduced magnetic Zr5 Ni5 nanoparticles (<20 nm). The acid-base bifunctionality of these nanocatalysts plays a synergic role in the synthesis of GVL in alcohols, whereas appropriate control of the nickel/zirconium molar ratio is able to improve the selectivity towards GVL (≈98 %), along with high formation rates (up to 54.9 mmol g-1  h-1 ). Moreover, the magnetic Zr5 Ni5 nanoparticles were conveniently recovered by means of a magnet for five cycles with almost constant activity.