Feasibility analysis of oil shale catalyzed water electrolysis for hydrogen production

Carbon-assisted catalytic hydroelectrolysis (CAWE) has been demonstrated to significantly reduce energy consumption and enhance the economic viability of hydrogen production. In this study, BP oil shale was employed as an additive in a sulfuric acid environment for catalytic water electrolysis experiments. The results indicate a pronounced increase in current when the voltage reaches 1.42 V. Analysis reveals that iron ions (Fe²⁺/Fe³⁺) play a dual role in facilitating charge transfer and mediating the redox cycle; however, their catalytic efficiency is constrained by the organo-mineral passivation layer that progressively forms on the surface of the oil shale. Utilizing a solid-liquid phase separation method, comparative analysis shows that the maximum current density of liquid-phase electrolysis reaches 8 mA, which is double that of solid-phase electrolysis. However, the current decays rapidly, and stability duration is reduced by 78 % compared to the solid-phase system. Gas chromatographic characterization of the anode products indicates a partial oxidation pathway involving intermediate hydrocarbons (CnHmXy), rather than corresponding gas formation. This study confirms that optimizing the iron regeneration pathway and inhibiting surface passivation are critical breakthroughs for promoting the engineering application of this technology. These findings provide basic insights into the catalytic hydroelectrolysis of oil shale for hydrogen production.