Using our expertise in sustainable technologies we have developed a mercury-free catalyst to support a more environmentally friendly method of producing PVC

An element map showing how gold (green in the map) sits only on the surface of our egg shell catalyst
An element map showing how gold (green in the map) sits only on the surface of our egg shell catalyst

The manufacture of vinyl chloride monomer (VCM) is an important intermediate step in the production of poly vinyl chloride (PVC) and today, much of the world's production requires a mercury based catalyst.

In October 2013, 90 countries signed the Minamata Convention on Mercury which is a binding international treaty aimed at controlling and reducing emissions of toxic mercury compounds. As a result, after 2017 VCM plants will need to switch to a mercury-free catalyst, providing there is an economically available alternative.

Through applying our expertise, we were able to produce the catalyst using an environmentally friendly manufacturing process Johnson Matthey has successfully developed a catalyst which does not contain any mercury for the manufacture of VCM, following on from a joint project with Cardiff University. Our catalyst uses gold as the active component which is carefully positioned on the surface of a carbon support material. This can be seen in the 'element map' on the above where the green colour represents the gold.

We call this an eggshell catalyst as the gold sits only on the surface. We have specifically designed it this way to minimise the amount of gold used and to make it readily available for reaction.

Sustainable manufacturing

As well as putting the gold in the right place, we also faced the challenge of producing it in a stable form. Through applying our expertise, we were able to stabilise the gold and produce the catalyst using an environmentally friendly manufacturing process.

We are currently commissioning the catalyst production plant in China which should be ready to produce commercial quantities of the new catalyst during 2015/16.

Through combining our chemistry skills and applications knowledge, we have successfully developed a new, economically viable catalyst that will enable a more sustainable route to PVC.

Cardiff University International Impact Award

The work between Johnson Matthey and Cardiff University won a Cardiff University International Impact Award in 2016, Sebastiaan van Haandel, Business Manager, at Johnson Matthey, said: "The award is a recognition of a great collaborative partnership between Cardiff University and Johnson Matthey, both in chemistry and chemical engineering. This novel catalyst, PRICAT™ MFC, is a further example of Johnson Matthey's capabilities in and commitment to sustainable technologies."