A single-phase Ni2Si nanoparticle catalyst was prepared successfully by using temperature programmed pyrolysis method with polydimethylsilane-Ni(acac)(2) as precursor and was characterized by thermogravimetric analysis, X-ray diffraction, X-ray photoelectron emission microscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The pyrolysis temperature for generating pure Ni2Si in H-2/Ar mixture is significantly lower than that for treatment in Ar. Ni2Si nanoparticles would be reduced to Ni nanoparticles by H-2 with increasing pyrolysis temperature (>600 C). The catalytic hydrogenation of phenylacetylene on Ni2Si nanoparticles was investigated at 1.0 MPa hydrogen and 80 C. The catalysts show suitable conversion of phenylacetylene and notable selectivity to styrene with 90%. In addition, catalytic performance on Ni2Si prominently improves after removing the 5i02 layer around Ni2Si nanoparticles by alkali treatment. (C) 2014 Elsevier B.V. All rights reserved.