Investigate the role of different inherent minerals in PEM based coal assisted water electrolysis cell

Coal assisted water electrolysis (CAWE) makes the pure hydrogen generation and renewable derived electricity storage practical with low cost. Different components of coal induce diverse reaction paths, and ions leached from the inherent minerals inevitably participate in the electrooxidation process. The role of inherent minerals in PEM-based CAWE cell was systematically investigated, and the coal samples were characterized by X-ray diffraction and FTIR before and after electrolysis. The results indicated that the different inherent minerals affected the current density in different ways. The oxidation of coal organic constituent and leached iron species required different onset potential and were responsible for partial current density in the low voltage range (0.8 V–1.2 V vs. SCE). In potentiostatic tests, the AAEMs ions led to sustainable increased current density by activating coal particles at the constant potential of 2 V; while the transition metal ions, such as Fe²⁺, tend to show stronger catalytic effect at relatively low cell potential (1.4 V vs. SCE). The evolution of oxygen-containing functional groups on coal particles surface also played an important role in the electrolysis process. The results provide a new perspective to study the promotion and inhibition mechanism of the inherent minerals.