Nanostructured Electrode Materials for High-Efficiency Hydrogen Generation from Salt-Water

Electrolysis of water is an appealing pathway to the production of clean hydrogen due to the ubiquity of water across the Earth. Unfortunately, hydrogen evolution from water requires very large overpotential and many water sources have high levels of dissolved solids that inhibit the electrolysis reaction, resulting in energy inefficient systems.  To address this challenge, framergy in collaboration with Texas A&M University proposes the use of a novel electrode material, namely metal-organic frameworks (MOFs) coated on MXene nanosheets, to both reduce the overpotential required for salt-water electrolysis and reduce the impact of dissolved solids on the long-term performance of the electrode. The MOF@MXene electrocatalyst will synergistically reduce the overpotential required for hydrogen production due to the nanostructuring of the material and the high activity of the MXene surface. Simultaneously, the porous MOF structure will exclude or adsorb dissolved solids found in natural salt-water sources. This will prevent blockage of active sites and reduce the prevalence of competing electrochemical reactions, further ensuring the longevity and high performance of the system. The low overpotential required for hydrogen generation ensures that small, portable, and modular energy sources, such as solar microgrids or onboard vehicle power sources, will be sufficient to operate the system.  The nanostructured design of the electrode surface will also eliminate the need for pre-processing of salt-water, an advantage over existing systems that require water with low levels of dissolved solids to operate efficiently. The team will evaluate the performance of the system by conducting hydrogen generation experiments using both simulated seawater and real-world natural water sources over hundreds of cycles. The team will also evaluate chemical compression methods that similarly utilize salt-water.