High pressure reactivity of phosphorus and hydrogen is relevant to fundamental chemistry, energy conversion and storage, and materials science. Here we report the synthesis of (PH₃)₂H₂, a crystalline van der Waals (vdW) compound (I4cm) made of PH₃ and H₂ molecules, in a Diamond Anvil Cell by direct catalyst-free high pressure (1.2 GPa) and high temperature (T ≲ 1000 K) chemical reaction of black phosphorus and liquid hydrogen, followed by room T compression above 3.5 GPa. Group 15 elements were previously not known to form H₂-containing vdW compounds of their molecular hydrides. The observation of (PH₃)₂H₂, identified by synchrotron X-ray diffraction and vibrational spectroscopy (FTIR, Raman), therefore represents the discovery of a previously missing tile, specifically corresponding to P for pnictogens, in the ability of non-metallic elements to form such compounds. Significant chemical implications encompass reactivity of the elements under extreme conditions, with the observation of the P analogue of the Haber-Bosch reaction for N, fundamental bond theory, and predicted high pressure superconductivity in P-H systems.

磷和氢的高压反应与基础化学、能量转换和储存以及材料科学有关。在这里，我们报道了 (PH ₃ ) ₂ H ₂的合成，这是一种由 PH ₃和 H ₂分子组成的结晶范德华 (vdW) 化合物 ( I 4 cm )，在金刚石砧池中通过直接无催化剂高压进行合成（ 1.2 GPa）和高温（ T≲ 1000 K）黑磷与液氢发生化学反应，然后进行室T压缩至3.5 GPa以上。此前并不知道第15族元素会形成其分子氢化物的含H ₂ vdW化合物。因此，通过同步加速器 X 射线衍射和振动光谱（FTIR、拉曼）鉴定的 (PH ₃ ) ₂ H ₂的观察代表了先前缺失的瓦片的发现，特别是对应于 pnictogens 的 P，具有非-金属元素形成此类化合物。重要的化学意义包括元素在极端条件下的反应性、观察到 N 的 Haber-Bosch 反应的 P 类似物、基本键理论以及预测的 PH 系统中的高压超导性。