Coupled Atmospheric Water Harvesting and Protonic Ceramic Electrolysis Enabling Self‐Sustained Green Hydrogen Production in Arid Regions

ABSTRACT Green hydrogen production in arid regions faces significant challenges due to the geographical mismatch between abundant renewable energy and severe water scarcity. To overcome this, a system coupling a sorption‐based atmospheric water harvesting (AWH) module with a protonic ceramic electrolysis cell (PCEC) module is presented. The AWH module, featuring dual sorbent units, capture airborne water and release it via recycled waste heat to generate continuous hot vapor streams for electrolysis in the PCEC module, thereby enabling nearly self‐sustained and continuous hydrogen production. To meet stringent operational requirement of PCEC, a novel AWH sorbent, hygroscopic polyacrylamide (HPAM) beads with highly interconnected macroporous architectures and superior low‐relative‐humidity moisture adsorption efficiency, has been developed through an emulsion‐templating method. An HPAM‐based AWH‐PCEC system demonstrates continuous, long‐term hydrogen production with an outstanding capacity of 2.12 mL min −1 cm −2 at 30% RH air environment. Distinctively, this hydrogen production process is liquid water‐free, operable without geographic or climatic constraints, and requires negligible additional energy input for water acquisition. The presented AWH‐PCEC system therefore offers a promising pathway for reliable, cost‐effective, continuous, and high‐yield green hydrogen production, with particular potential for applications in arid regions.