Stable reduced Ni catalysts for xylose hydrogenation in aqueous medium

Abstract Precursor materials with 20 wt.% nickel content and formula mater Nd 1-x Ce x Al 0.162 Ni 0.838 O 3 (x = 0.0, 0.1, 0.5, 0.7) were successfully used to prepare reduced Ni nanoclusters to be used as catalysts in the catalytic hydrogenation of xylose to xylitol. Reduction at 500 °C led to large reduced nickel content with almost no changes in the structure of the started mixed oxide precursors. The catalytic performance of the Ni-reduced catalysts did not show a clear relation with Ce content while a close dependence of the hydrogenated products with Ni° crystal size and the isomerization product with acidity was obtained. The well-known Ni leaching in aqueous medium was absent in the prepared Ni-reduced catalysts corroborating the promising use of crystalline mixed oxides as precursors to prepare stabilized Ni-reduced catalysts for aqueous-phase processing of biomass-derived compounds.