Palladium nanocrystals were prepared as a model product by membrane absorption of hydrogen for the first time. The effects of stabilizers and metallic compound concentrations on the nanocrystals morphology were studied. Poly(vinyl pyrrolidone), polyethylene glycol and cetyltrimethylammonium bromide exhibited good effects for particles passivation. The particle size declined with increased stabilizer-to-PdCl(2) molar ratio or decreased PdCl(4)(2-) concentration, and the average size was about 5 nm. The Pd nanocrystals showed excellent catalytic activity in hydrogenation of styrene. (C) 2011 Elsevier B.V. All rights reserved.