Chemical nanostructure could offer precise catalysis control

Scientists have been trying to develop so-called yolk-shell catalysts as a means of imparting greater selectivity on heterogeneous catalysis, a process used in most industrial chemistry, including the manufacture of fine chemicals, petrochemicals and agrochemicals.

Boston College assistant professor of chemistry Chia-Kuang Tsung and his team have developed a nanostructure that can regulate chemical reactions due to a thin, porous skin capable of precisely filtering molecules based on their size or chemical make-up, the group reported recently in the Journal of the American Chemical Society.

‘The idea is to make a smarter catalyst,’ said Tsung in a statement. ‘To do that, we placed a layer of “skin” on the surface that can discriminate between which chemical reacts or does not react with the catalyst.’

The team started with a nanoscale metallic crystal, then applied a ‘sacrificial layer’ of copper oxide over it, Tsung said.

Next, a shell of highly refined material known as a metal-organic framework (MOF), was applied to the structure. Immediately, the polycrystalline MOF adhered to the cooper oxide, forming an outer layer of porous ‘skin’.