Amidst the growing importance of hydrogen in a sustainable future, it is crucial to develop coatings that can protect hydrogen-sensitive system components in reactive hydrogen environments. However, the prediction of the chemical stability of materials in hydrogen is not fully understood. In this study, we show that the work function is a key parameter determining the reducibility (i.e., denitridation) of transition metal nitrides (TMNs) in hydrogen radicals (H*) at elevated temperatures. We demonstrate that, when the work function of a TMN system drops below a threshold limit (ϕ_TH), its reduction effectively stops. We propose that this is due to the preferential binding of H* to transition metal (TM) atoms rather than N atoms, which makes the formation of volatile species (NH_x) unfavorable. This finding provides a novel perspective for comprehending the interaction of hydrogen with TM compounds and allows prediction of the chemical stability of hydrogen-protective coatings.

中文翻译：

---

氢环境中过渡金属氮化物的功函数依赖性还原


随着氢在可持续未来中的重要性日益增加，开发能够在反应氢环境中保护氢敏感系统组件的涂料至关重要。然而，对材料在氢中的化学稳定性的预测尚不完全清楚。在这项研究中，我们表明功函数是决定高温下氢自由基 （H*） 中过渡金属氮化物 （TMN） 的还原性（即脱硝化）的关键参数。我们证明，当 TMN 系统的工作函数低于阈值限制 （φ_TH） 时，其减少实际上会停止。我们提出这是由于 H* 优先与过渡金属 （TM） 原子而不是 N 原子结合，这使得挥发性物质 （NH_x） 的形成不利。这一发现为理解氢与 TM 化合物的相互作用提供了一种新的视角，并允许预测氢保护涂层的化学稳定性。