Solar-Driven Hydrogen Production from Methanol Decomposition Catalyzed by High-Entropy Spinel Oxides

To address safety and economic issues in hydrogen storage and transportation, developing liquid organic hydrogen carriers to deliver hydrogen to where it can be utilized for in situ hydrogen production is an attractive approach. Herein, a spinel phase high-entropy oxide (HEO) (FeCrCoNiCu)₃O₄ comprising of non-noble metals is synthesized via the PVP (Polyvinyl Pyrrolidone)-templated method as a catalyst for solar-driven hydrogen production through methanol decomposition. Benefiting from the synergistic effects of various components in high-entropy materials, (FeCrCoNiCu)₃O₄ HEO achieves an optimized hydrogen production rate of 49.4 mmol g^-1 min^-1, with a surface temperature of 279 °C under full-spectrum illumination of 2.68 W cm^-2. The performance is significantly higher than that under thermocatalytic conditions at the same temperature and surpasses the activity of the state-of-the-art catalysts. The catalyst exhibits long-term stability over 80 h through in situ removing deposited carbon, and thus HEOs show great promise for efficient hydrogen production from methanol decomposition under mild conditions.