Styrene, a monomer widely used to synthesise polystyrene and various copolymers, is produced at the billion-pound-per-year level largely from catalytic dehydrogenation of ethylbenzene over a potassium-promoted iron oxide catalyst. To prevent buildup of "coke," a carbonaceous material that deactivates the catalyst is used. The reaction is carried out at high temperature in the presence of a large volume of steam, making ethylbenzene dehydrogenation an energy-intensive process. After a few hours' exposure to ethylbenzene, the commercial catalyst's activity drops rapidly and its surface becomes coated with coke.

Nanodiamond Catalyst

But acid-treated diamond nanoparticles can catalyze ethylbenzene dehydrogenation readily without accumulating coke, thereby eliminating the need for steam and reduce the energy needs of the process. During reaction the nanodiamond surface remains clean even after a few days' exposure, its activity remains constant at nearly three times the value of the iron catalyst and several times more active than carbon nanotubes, activated carbon, and other carbon materials. The catalyst has high activity due to its hybrid structure having particles with roughly 5 nm cores and a thin, defective grapheme like shell functionalized with ketone, diketone, and other oxygen containing groups which serve as electron donors and alkane moiety of activate ethylbenzene. Nanodiamond catalysts will be cost effective replacements for iron-based styrene catalysts at commercial volumes. This research will lead to new nonmetal catalytic materials which can lead to improvements in petrochemical processing.