Going beyond gold?

Experts from Cardiff University have proposed a much cheaper and more efficient way of producing a promising new catalyst that is used in reactions to produce a whole host of everyday materials, from electronics and cosmetics to sanitisation and pharmaceuticals.

The team, from the Cardiff Catalysis Institute, have devised a new way of creating the catalyst graphitic oxide – a compound that is a pre-cursor to the ‘wonder material’ graphene – and shown how this can be effectively used in reactions to produce a widely used material called epoxide.

Graphitic oxides are commonly prepared using the Hummers method; however, in their new study, which has been published in the journal Nature Communications, the team show that a less conventional method, known as the Hofmann method, leads to much better catalysis.

Whereas the Hummers method leads to the accumulation of sulfur on the surface of the graphitic oxide catalyst, which effectively acts as a poison for reactions, the Hofmann method was much more efficient and could enable researchers to carefully tune the surface of the catalyst.

Since its discovery in 2004, graphene and its related materials have been of interest to researchers all over the world due to their remarkable properties.

This has also led to the exploration of graphene-related materials in the field of catalysis – the development of materials to speed up chemical reactions in order to make products cheaper, cleaner and more efficient.

The latest research is part of a wider project building on the large success of research into gold catalysis by the Cardiff Catalysis Institute, and aims at replacing gold catalysts with cheaper and more sustainable alternatives.

Professor Graham Hutchings, Director of the Cardiff Catalysis Institute, made a landmark discovery that gold is a remarkable catalyst for certain reactions, most notably the production of vinyl chloride – the main ingredient of PVC.

Commenting on the new findings, Professor Hutchings said: “As we look beyond gold to other, more promising materials such as those associated with graphene, this paper is a significant first step along that path.

“Our paper has shown that the most commonly used method used to produce a graphitic oxide catalyst, the Hummers method, leads not only to far different materials, but also inferior catalysts to those prepared by other less conventional methods.

“This is vitally important as graphitic oxide is used as a catalyst to create epoxides, which are found in a vast array of materials that we see around us each day. The findings are also critically important for researchers looking to exploit the remarkable properties of graphene and its related analogues.”