Cable‐Car Electrocatalysis to Drive Fully Decoupled Water Splitting

The increasing demand for clean energy conversion and storage has increased interest in hydrogen production via electrolytic water splitting. However, the simultaneous production of hydrogen and oxygen in this process poses a challenge in extracting pure hydrogen without using ionic conducting membranes. Researchers have developed various innovative designs to overcome this issue, but continuous water splitting in separated tanks remains a desirable approach. This study presents a novel, continuous roll‐to‐roll process that enables fully decoupled hydrogen evaluation reaction (HER) and oxygen evolution reaction (OER) in two separate electrolyte tanks. The system utilizes specially designed “cable‐car” electrodes (CCE) that cycle between the HER and OER tanks, resulting in continuous hydrogen production with a purity of over 99.9% and Coulombic efficiency of 98% for prolonged periods. This membrane‐free water splitting system offers promising prospects for scaled‐up industrial‐scale green hydrogen production, as it reduces the cost and complexity of the system, and allows for the use of renewable energy sources to power the electrolysis process, thus reducing the carbon footprint of hydrogen production.