Highly Efficient Vapor-Phase Hydrogenation of Biomass-Derived Levulinic Acid Over Structured Nanowall-Like Nickel-Based Catalyst

With ever increasing demand of sustainable energy, biomass has been regarded as an ideal alternative to fossil resources. Herein, hierarchical three-dimensional nickel-based nanowalls on a nickel foam substrate were fabricated by a Ni-Zr-Al layered double hydroxide (NiZrAl-LDH) precursor route, which involved in situ growth of the Zr-containing precursor on the Ni foam strut through surface activation without an external nickel source. After calcination-reduction treatment, the nanowalls were applied as a structured catalyst for selectively hydrogenating biomass-derived levulinic acid to g-valerolactone. Systematic characterization revealed that highly dispersed Ni nanoparticles could be generated on the platelet-like Zr-containing oxide matrix derived from hierarchical 3D NiZrAl-LDH nanowalls. Under vapor-phase, solvent-free hydrogenation conditions (250 degrees C, ambient pressure), the yield and productivity for as-fabricated Ni-based structured catalyst could reach as high as 97.7% and 5.747 kg(GVL)kg(cat)(-1) h(-1), respectively. Such high catalytic efficiency was reasonably attributable to highly dispersed Ni nanoparticles and abundant surface Lewis acid sites, as well as favorable heat-transfer nature of present catalytic system. Moreover, the newly developed structured nanowall-like Ni-based catalyst possesses high structural and chemical stability, which makes the vapor-phase hydrogenation process promising in terms of green sustainable chemistry.