英国牛津大学Gouverneur Vronique研究团队报道了氟石在水中低温活化成含氟化学品。相关研究成果发表在2024年11月13日出版的《自然》。

危险的化学物质氟化氢位于含氟化学品行业的顶端，但与在恶劣条件下（300℃以上）生产和运输相关的重大危险通常由专业人员承担。所有用于制冷、电动运输、农用化学品和药品等应用的含氟化学品，都是由萤石（CaF₂）通过产生高度危险的氟化氢的程序制备的。

该文中，研究人员报告了一种直接从萤石中获得含氟化合物的温和方法，绕过了制造氟化氢的必要性。酸级萤石（超过97%的CaF₂）在草酸（一种对Ca²⁺螯合非常有效的布朗斯特酸）的存在下，用亲氟路易斯酸硼酸（B（OH）₃）或二氧化硅（SiO₂）处理。

这种可扩展的工艺在低温（低于50℃）的水中进行，可以获得广泛使用的含氟化合物，包括四氟硼酸、碱金属氟化物、四烷基氟化铵和氟（杂）芳烃。用硫酸代替草酸对B（OH）₃产生了类似的结果，但当亲氟路易斯酸为SiO₂时效果不佳。

类似的工艺也适用于较低纯度的甲长石。直接从萤石中生产含氟化学品提供了分散制造的可能性，这对含氟化学品行业来说是一种有吸引力的模式。

随着人们对通过二氧化碳捕获和生物质合成草酸的创新方法重新产生兴趣，以及人们对化石燃料硫和硫酸供应的依赖所带来的挑战，该技术可能代表着向可持续的含氟化学品行业的转变。

附：英文原文

Title: Fluorspar to fluorochemicals upon low-temperature activation in water

Author: Klose, Immo, Patel, Calum, Mondal, Anirban, Schwarz, Andrew, Pupo, Gabriele, Gouverneur, Vronique

Issue&Volume: 2024-11-13

Abstract: The dangerous chemical hydrogen fluoride sits at the apex of the fluorochemical industry, but the substantial hazards linked to its production under harsh conditions (above 300degrees Celsius) and transport are typically contracted to specialists. All fluorochemicals for applications, including refrigeration, electric transportation, agrochemicals and pharmaceuticals, are prepared from fluorspar (CaF2) through a procedure that generates highly dangerous hydrogen fluoride1,2,3,4,5. Here we report a mild method to obtain fluorochemicals directly from fluorspar, bypassing the necessity to manufacture hydrogen fluoride. Acid-grade fluorspar (more than 97per cent CaF2) is treated with the fluorophilic Lewis acid boric acid (B(OH)3) or silicon dioxide (SiO2), in the presence of oxalic acid, a Brnsted acid that is highly effective for Ca2+ sequestration. This scalable process carried out in water at low temperature (below 50degrees Celsius) enables access to widely used fluorochemicals, including tetrafluoroboric acid, alkali metal fluorides, tetraalkylammonium fluorides and fluoro(hetero)arenes. The replacement of oxalic acid with sulfuric acid gave comparable results for B(OH)3, but was not as effective when the fluorophilic Lewis acid was SiO2. A similar process also works with the lower-purity metspar. The production of fluorochemicals directly from fluorspar offers the possibility of decentralized manufacturing—an attractive model for the fluorochemical industry. With the renewed interest in innovative methods to synthesize oxalic acid via carbon dioxide capture and biomass6,7, and the challenges posed by our dependence on fossil fuels for sulfur and therefore sulfuric acid supply8,9, our technology may represent a departure towards a sustainable fluorochemical industry.

DOI: 10.1038/s41586-024-08125-1

Source: https://www.nature.com/articles/s41586-024-08125-1