A series of boron nitride (BN) supported Pt-Sn catalysts was prepared with a co-incipient wetness method employing hexachloroplatinic acid and tin(II) chloride. Pt loading was fixed at 1.1 wt%; Sn loading varied from 0.25 to 0.75 wt% on BN support. Selective hydrogenation of gas-phase crotonaldehyde was conducted in a steady-state flow reactor with temperatures ranging from 40 to 100 degrees C. The selectivity of crotyl alcohol reached over 80%. An optimum yield of crotyl alcohol reached 38% at 60% conversion of crotonaldehyde at 80 degrees C using Pt-Sn(0.75)/BN catalyst, while Pt-Sn(0.75)/gamma-Al2O3 yielded less crotyl alcohol and a lower rate of crotonaldehyde conversion. The maximum yield rate of crotyl alcohol was 2.4 mmol/(g-cat. h) at 80 degrees C. Negligible deactivation was found during reaction for 4-6 h. The crystalline phases of PtSn and SnPt3 alloys were observed from the XRD spectra of Pt-Sn/BN catalysts with various Sn loadings. The selectivity of crotyl alcohol increased with Sn loadings but the activity values of the catalysts went through a maximum. The H-2 reduction at 300 degrees C gave an optimum PtSn alloy particle size so that the selectivity of crotyl alcohol increased without losing catalyst activity. The C=O bond of crotonaldehyde was preferentially hydrogenated and the hydrogenation of C=C bond was suppressed, resulting in the increase of crotyl alcohol selectivity. (c) 2005 Elsevier B.V. All rights reserved.