Copper-catalyzed propylene epoxidation by molecular oxygen:: Superior catalytic performances of halogen-free K+-modified CuOx/SBA-15

A halogen-free K+-modified CuOx/SBA-15 exhibits significantly better catalytic performance than other Cu-based catalysts reported so far for the epoxidation of propylene by molecular oxygen. Moderate selectivity (ca. 15-50%) to propylene oxide (PO) can be sustained as propylene conversion increases from ca. 1 to 12%, and a PO formation rate of 2.1 mmol g(-1) h(-1) has been obtained over this catalyst. The current catalyst does not require prereduction, and the PO selectivity can be kept at a high O-2 partial pressure or a highly O-2-rich atmosphere. (c) 2006 Elsevier Inc. All fights reserved.