Novel BN supported bi-metal catalyst for oxydehydrogenation of propane

A novel boron nitride (BN) supported Pt-Sn catalyst was used for the oxydehydrogenation of propane. BN is a graphite-like inert. support which provides negligible interaction with metals. The Pt-Sn/BN catalysts were prepared by co-incipient wetness impregnation with various Sn loadings. A commercial support gamma-Al2O3 was chosen to compare with BN. PtSn alloys were formed due to the partially reduced Sn in Pt-Sn/BN catalyst in H-2 at 400 degrees C. Furthermore, the crystalline phases of PtSn and SnPt3 alloys were also observed from the XRD patterns of Pt-Sn/BN catalysts. However, PtSn alloys were not detected in Pt-Sn/gamma-Al2O3 by XRD. The Sn addition clearly improved the activity and propylene selectivity of Pt-Sn/BN at 600 degrees C. The more the Sn loading, the higher the selectivity and yield of propylene were. A maximum yield of propylene (38.3%) was achieved on Pt-Sn (0.75 wt%)/BN catalyst at the start of reaction. The catalysts, Pt-Sn/gamma-Al2O3, deactivated more rapidly than Pt-Sn/BN. The activity and selectivity enhancement are attributed to the formation of PtSn and/or SnPt3 alloy particles on the BN support. Compared with the hydrophilic gamma-Al2O3, the hydrophobic BN surface can expel H2O during the oxidation of hydrogen resulting in the activity increase. (C) 2007 Elsevier B.V. All rights reserved.