New Catalytic Materials for the Direct Epoxidation of Propylene by Molecular Oxygen

The direct vapor‐phase production of propylene oxide (PO) from propylene and molecular oxygen without the use of a co‐reactant remains a challenging problem in industrial catalysis, in spite of several decades of research. Herein, the discovery of a new class of silica‐supported multimetallic RuO 2 –CuO x –NaCl catalysts for the direct synthesis of PO from propylene and molecular oxygen is reported. This trimetallic catalyst exhibits durability and delivers PO selectivities of 40–50 % at propylene conversions of 10–20 % within 240‐270 °C and at atmospheric pressure. The best performing catalysts are characterized by powder X‐ray diffraction (PXRD) and transmission electron microscopy (TEM) and are determined to be composed of nanocrystalline domains of the three phases of RuO 2 , CuO x , and NaCl.