Blueprint for a modern sustainable phosphorus chemistry

目前可用初级磷资源的枯竭非常令人担忧，这就是欧盟将磷矿和元素磷列入关键原材料清单的原因。到目前为止，从磷矿到基础化学品的价值链并不符合“绿色化学”的指导原则。此外，通过适当的大规模回收工艺回收有价值的磷化合物的磷回收问题在未来将变得更加尖锐。因此，迫切需要在重要元素磷的价值链中开发新的和创新的化学方法。在我们的现代可持续磷化学蓝图中，我们研究了系统以及原子和能源高效的方法来脱氧磷酸和回收磷酸盐资源(从污水污泥中提取鸟粪石，从阴极材料中提取LiFePO4)。我们的方法的优点是避免了非常耗能的磷酸盐到白磷的转化(P(V)还原到P(0))和再氧化/氯化成目前最重要的磷中间体PCl3、OPCl3和P4O10(P(0)氧化成P(III)或P(V))。我们在这里的目标是将磷酸盐(PO43-)或其他P(V)试剂直接转化为P(1)构件，从而允许“氧化还原中性”合成各种有价值的P(V)化合物，从而提供直接访问各种平台化学品的途径。此外，从这些P(V)化合物开始，我们将开发P(III)化合物(如膦)的电化学还原过程。在碱(例如LN)存在的情况下，磷酸盐资源与合适的酸酐(例如Tf2O)的转化将提供P1构建块，包括那些类型为(LN)2PO2[OTf]的构建块，其可以“中性地”转化为磷(V)平台化学物质。这一方法的一个具有挑战性的扩展是合成各种PF6盐，这些盐对电池电解液非常重要，从问题严重的贫化化合物UF6开始。通过这一探索性项目，我们将把可持续磷化学的新方法与处理贫化六氟化铀(UF6)的替代合成路线结合起来，从而总体上有助于解决现代化学中最紧迫的问题之一--不可再生和/或关键资源的可持续管理和危险废物的风险缓解。

The current depletion of available primary phosphorus resources is extremely worrying, which is why the EU has included phosphate rock and elemental phosphorus in the list of critical raw materials. So far, the value chain from phosphate ores to basic chemicals does not correspond to the guiding principle of "green chemistry". In addition, the problem of phosphorus recovery through suitable large-scale recycling processes to recover valuable phosphorus compounds will become drastically more acute in the future. For these reasons, the development of new and innovative chemical methods in the value chain of the important element phosphorus is urgently needed. In our blueprint for a modern sustainable phosphorus chemistry, we investigate systematic as well as atom and energy efficient ways to deoxygenate phosphoric acid and recycled phosphate resources (struvite from sewage sludge, LiFePO4 from cathode material). The advantage of our approach is the avoidance of the very energy-intensive conversion of phosphate to white phosphorus (reduction of P(V) to P(0)) and reoxidation/chlorination to the currently most important phosphorus intermediates PCl3, OPCl3 and P4O10 (oxidation of P(0) to P(III) or P(V)). Our goal here is the direct conversion of phosphates (PO43-) or other P(V) reagents to P1 building blocks, allowing "redox neutral" synthesis of a variety of valuable P(V) compounds, thus providing direct access to a wide range of platform chemicals. Furthermore, starting from these P(V) compounds, we will develop electrochemical reduction processes to P(III) compounds (e.g. phosphanes). The conversion of phosphate resources with suitable anhydrides (e.g., Tf2O) in the presence of a base (e.g., LN) will provide P1 building blocks, including those of the type (LN)2PO2[OTf], which can be converted "redox neutrally" to phosphorus (V) platform chemicals. A challenging extension of this approach is the synthesis of various PF6 salts, very important for battery electrolytes, starting from the highly problematic depleted compound UF6. With this exploratory project, we will combine new approaches in sustainable phosphorus chemistry with alternative synthetic routes for the disposal of depleted uranium hexafluoride (UF6), thus contributing overall to one of the most pressing problems of modern chemistry - the sustainable management of non-renewable and/or critical resources and risk mitigation of hazardous waste.