PVP-stabilized NiB catalysts were prepared using the chemical reduction method with NaBH4, dissolving the water-soluble polymer of polyvinylpyrrolidone (PVP) in the precursor salt solution as a protective reagent. The PVP-NiB catalysts were characterized and examined for their catalysis on the hydrogeneration of furfural, crotonaldehyde and citral. PVP polymer could adsorb on the nano-particles of NiB via a weak coordination bonding and stabilize it: a molecular weight of PVP of about 10,000 was suitable, and the optimal quantity of PVP (PVP/Ni) in the salt solution for preparing catalysts was around 20. The PVP-NiB samples were characterized by XRD as an amorphous structure and by TEM with a particle size distribution in the range of 3-5 nm. On catalysis, the PVP-NiB catalyst was significantly more active and slightly more selective than NiB for hydrogenating furfural to furfuryl alcohol and crotonaldehyde to butyraldehyde. A good yield of citronellal, about 90%. could be obtained by reducing citral in cyclohexane at a low reaction temperature of 50 degrees C over the PVP-NiB catalyst. (c) 2005 Elsevier B.V. All rights reserved.