Iron Ion Enables Photocatalytic Hydrogen Evolution from Methanol

Abstract Global demand for hydrogen gas (H2) is projected to increase significantly, driven by efforts to achieve carbon neutrality. This surge in demand is largely due to its advantage of emitting no carbon dioxide during the use of H2, making it a promising clean energy. Consequently, technologies for utilizing H2, such as fuel cells, are being actively developed. However, H2 is currently produced industrially from fossil fuels like natural gas and oil. Therefore, developing practical methods for producing clean H₂ without relying on fossil resources is an urgent challenge. Current technologies enable H₂ production from water using electricity or light, and research is advancing on producing H2 from alcohols such as methanol and ethanol, which have high affinity with renewable resources, as well as from sewage sludge, waste plastics, and other feedstocks. Nevertheless, cost remains a significant barrier to the practical implementation of these technologies. Overcoming this barrier requires innovative approaches. In this context, we have successfully developed a dehydrogenation reaction from alcohols using iron (Fe), the most abundant and inexpensive metal on Earth, as a catalyst. This reaction is driven by renewable energy source of light, contributing to the establishment of a sustainable reaction system. The catalytic activity of this system for methanol dehydrogenation is comparable to that reported in previous studies. This simple and effective catalytic system, discovered serendipitously, has no documented analogs, to the best of our knowledge.