R2R − From Rock to Reagent: Mechanistic and Mechanochemical Studies toward Fluoride Release from Fluorapatite.

• Applicant: Dr. Johanna Schlögl
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation ; Solid State and Surface Chemistry, Material Synthesis
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 588244189

Fluorine is a key element of our modern world. A broad variety of industry sectors, ranging from pharmaceuticals and agriculture to functional materials and energy technologies, increasingly rely on new fluorinated molecules. At the moment, fluorine is almost exclusively sourced from fluorspar, a finite mineral predicted to be depleted within the next decades. Fluorapatite (FAP), naturally occurring in abundant resources of phosphate rock (PR), offers a promising alternative. Harvesting the fluoride content in PR could not only provide a sustainable source of fluoride, but also benefit the phosphorous industry by preventing HF formation during phosphoric acid production. Currently, no economical process for PR defluorination exists, due to its insolubility and high lattice energy, making it a largely inert material. This project seeks to evaluate mechanochemical approaches to activate FAP in PR, both to enable transformation into valuable and practical fluorinating reagents and produce defluorinated PR as a safe feedstock for phosphoric acid production. We will build upon previous work regarding the successful mechanochemical activation of fluorspar and evaluate the applicability of these methods to FAP in PR. Beyond application-oriented investigations, we will perform fundamental studies to provide more information about the Ca−F interaction in FAP and assess its capabilities to act as a source of nucleophilic fluoride. To this end, a molecular, soluble mimic of FAP will be synthesized. Finally, a conceptually new route for the activation of mostly inert, sparingly soluble materials, such as fluorspar or FAP, will be explored. This approach seeks to combine mechanochemical activation via impact and friction forces with frustrated Lewis pair bond activation, a strategy that, to the best of our knowledge, has not been investigated. Overall, this project aims to contribute to the development of a sustainable fluorine economy.

• DFG Programme: Fellowship
• International Connection: United Kingdom
• Host: Professorin Véronique Gouverneur, Ph.D.