Green synthesis of propylene oxide directly from propane

Abstract

The chemical industry faces the challenge of bringing emissions of climate-damaging CO2 to zero. However, the synthesis of important intermediates, such as olefins or epoxides, is still associated with the release of large amounts of greenhouse gases. This is due to both a high energy input for many process steps and insufficient selectivity of the underlying catalysed reactions. Surprisingly, we found that the oxidation of propane at elevated temperature over inert materials such as boron nitride and silicon dioxide leads to the formation of significant amounts of propylene oxide in a mixture with propylene, with unexpectedly small amounts of CO2 being formed. Fragile products are usually synthesised on highly specific surfaces, which is associated with strong interactions. We demonstrate that rapid reaction over unspecific interfaces entails im-portant consequences for the synthesis of products prone to overoxidation. Process simulations reveal that the combined synthesis of these two important chemical building blocks is technologically feasible. Our discovery leads the ways towards an environmentally friendly production of propylene oxide and propylene in one step. A complex catalyst development is not necessary.