A safer path to fluorochemical production discovered

Professor Véronique Gouverneur

20 November 2024

Magdalen’s Waynflete Professor of Chemistry Professor Véronique Gouverneur and her team have developed a safer method to create fluorochemicals from fluorspar.

Fluorochemicals are hugely important as they are used to produce polymers, agrochemicals, pharmaceuticals, and batteries for phones and electric cars. However, they are currently created using the toxic gas hydrogen fluoride (HF) which is harmful to humans and animals, and bad for the environment. The normal process of generating fluorochemicals requires HF derived from fluorspar (CaF₂) under extreme conditions, exceeding 200°C.

This study represents an important step because the protocol developed in Oxford is easy to implement and does not require specialised equipment

Professor Véronique Gouverneur

But now researchers have developed a safer less energy-intensive method for creating fluorochemicals directly from fluorspar without the necessity to manufacture and transport HF. This process replaces harsh conditions with a milder approach, treating acid grade fluorspar (with over 97% CaF₂ content) using boric acid (B(OH)₃) or silicon dioxide (SiO₂) as fluorophilic Lewis acid, and oxalic acid, a Brønsted acid that effectively sequesters calcium ions.

“A solution to use CaF2 directly for fluorination chemistry, without the need for HF production, has been sought for decades,” said Professor Véronique Gouverneur. “This study represents an important step because the protocol developed in Oxford is easy to implement and does not require specialised equipment.”

Unlike traditional methods, this new process operates in water at temperatures below 50°C, making it far less energy-intensive. The process can be used to create widely used fluorochemicals, including tetrafluoroboric acid, fluoride salts, and fluoroaromatic compounds, which are essential across various sectors like agriculture, and medicine.

By eliminating the need for HF, this new technology offers hope for a future where essential fluorochemicals can be produced with improved safety for both humans and ecosystems.

Fluorspar to fluorochemicals upon low-temperature activation in water is published online in Nature at https://www.nature.com/articles/s41586-024-08125-1