(483f) New Catalytic Materials for the Direct Epoxidation of Propylene by Molecular Oxygen

Propylene oxide (PO) is an important and versatile intermediate used in the production of a large variety of valuable consumer products such as polyurethane foams, polymers, propylene glycol, cosmetics, food emulsifiers and as fumigants and insecticides. Over ten billion pounds of PO are produced annually from propylene, representing a business worth over $6 billion. Currently the majority of the PO is produced by the chlorohydrin and peroxidation processes, both of which are besieged by the formation of significant amounts of co-products, some of which also pose environmental hazards. Recently, a process using H2O2 have also been commercialized. The disadvantage of the H2O2 processes is the added cost of the hydrogen peroxide used. In addition, there would be safety concerns when H2O2 is produced in situ from H2. In short, all of the existing manufacturing processes as well as the newer ones under development are wrought with economic, environmental and safety concerns. Here we report the discovery of a new class of silica-supported multimetallic RuO2-CuO-NaCl catalysts for the direct synthesis of PO from propylene and molecular oxygen. This trimetallic catalyst exhibits durability and deliver PO selectivities of 40-50% at propylene conversions of 10-20% within 240-270°C and at 1 atm.