Optimization of operational parameters in the mechanochemical regeneration of sodium borohydride (NaBH4)

In this study we investigate the mechanochemical regeneration of sodium borohydride (NaBH4) from a system comprising hydrated sodium metaborate (NaBO2 center dot 4 H2O) and magnesium hydride (MgH2). We explore the individual and joint impact of key operational parameters (rotational speed, milling time, ball-to-powder ratio (BPR), and molar ratio) on the regeneration yield. Furthermore, a method for quantifying chemical conversion is introduced relying only on water and thus, offering environmental benefits. This approach additionally facilitates the production and storage of a "ready-to-use"NaBH4 solution with minimal losses at room temperature. Notably, a yield of 90% is achieved, with a 20% reduction in rotational speed compared to prior literature. This research contributes to sustainable hydrogen storage and presents practical advancements in mechanochemical processes.