For the first time, they manage to produce fluorochemicals without the risk of using hydrogen fluoride

July 21 () –

Chemists from Oxford University (UK) have developed an entirely new method pto generate for the first time fluorochemicals, critical to many industries, without using the dangerous gas hydrogen fluoride, as published in the journal ‘Science’. The innovative method is inspired by the biomineralization process that forms teeth and bones and could have a huge impact in improving the safety and carbon footprint of a growing global industry.

The Fluorochemicals are a group of chemicals that have a wide range of important applications. -including polymers, agrochemicals, pharmaceuticals and the lithium-ion batteries in smartphones and electric cars- with a global market of 21.4 billion dollars in 2018 (about 19,000 million euros).

Currently, all fluorochemicals are generated from the toxic and corrosive gas hydrogen fluoride (HF) in a process that consumes a lot of energy. Despite strict safety regulations, in recent decades there have been numerous HF spills, sometimes with fatal accidents and detrimental environmental effects.

To develop a safer method, a team of chemists from the University of Oxford, along with colleagues from the Oxford spin-off FluoRok, University College London and Colorado State University in the United States, were inspired by the natural biomineralization process that forms teeth and bones. HF itself is typically produced by reacting a crystalline mineral called fluorite (CaF2) with sulfuric acid under very harsh conditions, before using it to make fluorochemicals. With the new method, fluorochemicals are made directly from CaF2, bypassing HF production entirely – a feat chemists had been seeking for decades.

In the new method, solid-state CaF2 is activated through a biomineralization-inspired process, which mimics the way calcium phosphate minerals form biologically in teeth and bone.. The team ground CaF2 with powdered potassium phosphate salt in a ball mill for several hours, using a mechanochemical process that has evolved from the traditional way of grinding spices in a mortar and pestle.

The resulting powdered product, called Fluoromix, allowed the synthesis of more than 50 different fluorochemicals directly from CaF2, with up to 98% yield. The developed method has the potential to streamline the current supply chain and reduce energy needshelping to meet future sustainability targets and reduce the industry’s carbon footprint.

It is exciting that the solid state process developed was just as effective with acid grade fluorite (>97%, CaF2) as it was with synthetic reagent grade CaF2. The process represents a paradigm shift for fluorochemical manufacturing worldwide and has led to the creation of FluoRok, a spin-off company focused on commercializing this technology and developing safe, sustainable, and cost-effective fluorinations. The researchers hope that this study will encourage scientists around the world to come up with disruptive solutions to complex chemical problems, with the prospect of societal benefits.

Calum Patel, from the Department of Chemistry at the University of Oxford and one of the study’s lead authors, explains that “the mechanochemical activation of CaF2 with a phosphate salt was an exciting invention because this seemingly simple process represents a very effective solution to a complex problem, however, big questions remained about how this reaction works. Collaboration was key in answering these questions and advancing our understanding of this new and unexplored area of ​​fluorine chemistry.. Successful solutions to grand challenges emerge from multidisciplinary approaches and insights, and I believe this work underscores their importance.”

For her part, lead author Professor Véronique Gouverneur FRS, from the Department of Chemistry at the University of Oxford, who conceived and led this study, states that “direct use of CaF2 for fluorination is a holy grail in this field, and a solution to this problem has been sought for decades. The transition to sustainable methods of chemical manufacturing, with little or no impact on the environment, is now a priority goal that can be accelerated with ambitious programs and a complete rethink of current manufacturing processes.”

“This study represents an important step in this direction because the method developed at Oxford has the potential to be applied anywhere in academia and industry, minimize carbon emissionsfor example by shortening supply chains, and offer greater reliability in the face of fragile global supply chains”he concludes.