Engineers have found inspiration for a new class of industrial catalysts from enzymes – the proteins responsible for biological tasks such as speeding up chemical reactions within the body.
Researchers from Cardiff and Manchester universities have engineered nanoporous molecular crystals that are capable of maintaining their structure. This permanent porous matrix provides a place for chemical reactions to occur.
This is said to take scientists a step closer to making porous solids that can mimic the sophisticated chemistry found in nature.
The group believes that its new porous crystal, which is made from an iron-containing compound called phthalocyanine, will have reactivity similar to enzymes and produce more effective man-made catalysts.
The porous crystal has been designed to closely mimic an iron-containing enzyme known as hemoprotein, a type of protein that is unusual in the diversity of tasks it is able to perform.
Prof Neil McKeown, from Cardiff’s School of Chemistry, stated that, normally, the voids within nanoporous crystals of this type need to be filled with organic solvent. If this is removed they will collapse and lose their porosity and, therefore, the space in which to carry out chemical reactions.
However, by taking inspiration from the use of cavity wall ties in architectural engineering, he added, the team stabilised its crystals with the addition of suitable ligands that can bind simultaneously to two iron atoms and thus act as molecular wall ties.
The design of the crystal allows it to exist happily in water-based environments and remain accessible to gas molecules. This aspect makes it a contender for future industrial catalysts.
These features were examined at the Science and Technology Facilities Council’s Daresbury Laboratory on the Diamond light source.