Nanosized metallic molybdenum could be synthesized from MoO3 and KBH4 by solid-state reaction at moderate temperature. The crystallinity, morphology, surface properties of as-synthesized metallic molybdenum were investigated by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectral (XPS). The results of its catalytic activity test show that the as-synthesized nanosized metallic molybdenum is superior to the noble metal catalyst 0.3% Pd/Al2O3 for the selective hydrogenation of alkadienes at higher temperature and pressure. (C) 2003 Elsevier Ltd. All rights reserved.