New way to make Fluorochemicals

A method to prepare important fluorine-containing chemicals directly from the mineral fluorspar, bypassing the need to use highly toxic hydrogen fluoride (HF), has been discovered by scientists at Oxford University.

Key industrial polymers, agrochemicals, pharmaceuticals, and lithium-ion batteries in smartphones and electric cars – with a $21.4 billion global market in 2018 – all rely on fluorochemicals for their synthesis.

Currently these are made using the toxic and corrosive gas hydrogen fluoride (HF) in a highly energy-intensive, centuries old process. HF itself is produced by reacting the mineral fluorspar (CaF2) with sulphuric acid.

Despite stringent safety regulations, HF spills have occurred numerous times, sometimes with fatal consequences and detrimental environmental impacts.

Now a team led by Veronique Gouverneur at the University of Oxford have developed a way to made fluorochemicals directly from fluorspar.

Taking their inspiration from nature and the way calcium forms strong bonds with phosphate, such as in the formation of bones and teeth, the team found a way to make phosphate swap places with the fluoride in fluorspar by grinding them together.

Shaking a stainless-steel jar containing a stainless-steel ball and a mixture of fluorspar and a potassium phosphate salt often also used as a food additive, the ball collided with the two solids causing them to react.

The powdered product, called Fluoromix, turned out to be a highly reactive fluorinating reagent capable of making over 50 fluorochemicals including those important in drug compounds, antibiotics and fertilisers.

The process represents a breakthrough for the manufacturing of fluorochemicals across the globe, streamlining the current industrial process, negating the risky use of hydrogen fluoride, and with a lower carbon footprint.

The team have founded a spin-out company called FluoRok to focus on the commercialisation of this technology and the development of safe, sustainable and cost-effective fluorinations.

They hope that the discovery will encourage scientists around the globe to develop disruptive solutions to challenging chemical problems.