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Amid the global trend toward energy transition, hydrogen, as the \"ultimate energy source of the 21st century,\" is driving a revolution in the energy sector thanks to its clean, efficient, and sustainable properties. Traditional electrolytic water splitting for hydrogen production consumes freshwater resources, posing application limitations in certain specific scenarios. The vast oceans, which cover about 71% of the Earth’s surface, are the largest source of hydrogen on the planet. Hydrogen production from seawater has emerged as a solution that holds promise for addressing this issue. Two-track approach: An analysis of the technology pathways for hydrogen production from seawater. Hydrogen has a wide range of applications in the petroleum and petrochemical industries; in oil refining, it can be used to improve product quality in processes such as hydrodesulfurization, hydrocracking, and hydrorefining. It is also utilized for catalyst regeneration, as a shielding gas, and in waste gas treatment. Hydrogen is a key raw material for the synthesis of ammonia and methanol, and it can be used to produce fertilizers, plastics, and other products. Green hydrogen replaces fossil fuels in hydrogen production; by powering fuel cells, it helps reduce carbon emissions and facilitates a green transition. Currently, the main methods for hydrogen production include hydrogen production via natural gas reforming, coal gasification, industrial by-products, water electrolysis, as well as hydrogen production from biomass, water photolysis, and nuclear energy. In the energy transition, green hydrogen and blue hydrogen will become the main approaches for producing hydrogen with low carbon emissions. Among these, water electrolysis is the key technology for producing green hydrogen, and it includes methods such as alkaline water electrolysis (AWE), proton exchange membrane electrolysis (PEM), solid oxide electrolysis (SOEC), anion exchange membrane electrolysis (AEM), as well as seawater electrolysis. Since seawater contains about 3.5% salts, which has a significant impact on the hydrogen production process, seawater electrolysis for hydrogen production imposes higher requirements on key materials and equipment compared to conventional water electrolysis for hydrogen production. Currently, seawater electrolysis hydrogen production technologies are mainly divided into two types: one is the combination of seawater desalination with alkaline water hydrogen production (AWE) or proton exchange membrane (PEM) hydrogen production ； The second method is to produce hydrogen through electrolysis using seawater as the raw material. Most demonstration plants adopt the first technical approach; both seawater desalination and alkaline water hydrogen production possess a high level of technological maturity, and are easy to implement on an industrial scale. Hydrogen production via direct seawater electrolysis is divided into membrane-system-based seawater electrolysis methods for hydrogen production without desalination, and technology solutions based on corrosion-resistant materials. The electrolytic hydrogen production technology using seawater, without desalination, relies on the combination of special membrane materials with hydrogen production electrolyzers that use alkaline solutions. By utilizing the principle of concentration-driven separation, it is possible to effectively isolate the impurity ions in seawater from the circulating fluid in the hydrogen production electrolyzer, thereby enabling a stable hydrogen production process from seawater. The core of this technology lies in the development of membrane materials; essentially, pure water remains inside the electrolyzer. The technical solution based on corrosion-resistant materials involves using corrosion-resistant, highly active electrodes, high-mass-transfer electrode plates, as well as specific processing techniques to address the impact of impurity ions on hydrogen production, thereby ensuring the stable operation of the device. A major breakthrough: Advances in seawater hydrogen production technology. In the 1970s, scientists proposed the idea of producing hydrogen directly through the electrolysis of seawater. For nearly half a century, research teams at home and abroad have been conducting related studies. “Since the 14th Five-Year Plan, various policies and plans aimed at promoting the development of the hydrogen energy industry have been continuously introduced. In September 2021, the \"Opinions of the CPC Central Committee and the State Council on Fully and Accurately Implementing the New Development Concept to Achieve Carbon Peaking and Carbon Neutrality\" stated that it is necessary to strengthen research and development, demonstration, and large-scale application of key technologies related to hydrogen production, storage, and utilization, while promoting the development of the entire hydrogen value chain, from production to storage, transmission, and use. In October 2021, the \"Notice of the State Council on Issuing the Action Plan for Reaching Carbon Peak by 2030\" called for accelerating the research and development of hydrogen energy technologies as well as their pilot applications, with a view to exploring their large-scale use in industries, transportation, construction, and other fields. In March 2022, the **Development and Reform Commission** and the **Energy Bureau** jointly issued the \"Medium- and Long-Term Plan for the Development of the Hydrogen Energy Industry (2021–2035)\". In addition, many provinces and cities, as well as central and state-owned enterprises, have also made forward-looking plans for the hydrogen energy industry. In 2021, Sinopec Dalian Research Institute, with the support of Sinopec’s Science and Technology Department, studied the effects of impurity ions in seawater. By developing corrosion-resistant electrode materials, high-mass-transfer channel designs, and specialized electrolyte purification modules, it managed to overcome the impact of these impurity ions on hydrogen production processes, enabling simultaneous production of multiple products and thus further improving the overall utilization rate of seawater. In December 2024, Sinopec Dalian Research Institute, in collaboration with Qingdao Refining & Chemical Company, carried out research and development on the key materials, equipment, and processes related to the technology of producing hydrogen through the direct electrolysis of seawater, achieving significant technical breakthroughs; as a result, China’s first industrial-scale research project for hydrogen production from seawater was established. The device produces 20 standard cubic meters of hydrogen per hour; the hydrogen generated meets the requirements specified in GB/T37244-2018 for hydrogen used in fuel cell vehicles. It can be directly integrated into Qingdao Refining & Chemical’s hydrogen pipeline network, thereby accelerating the industrialization of technologies for producing hydrogen through the direct electrolysis of seawater in the future. Multiple approaches: Advancing the industrialization of hydrogen production from seawater. Although progress has been made in the industrialization of hydrogen production through seawater electrolysis, significant challenges remain in achieving large-scale, sustainable, and stable development. First, the large-scale development of technology faces challenges. Seawater has a complex composition, containing 92 chemical elements as well as a large number of microorganisms, which presents numerous technical challenges for the direct electrolysis of seawater to produce hydrogen. In particular, most of the technologies that have been developed so far are still at the pilot scale, with short operation times; there are still many issues that need to be resolved before these technologies can be scaled up for practical use. Second is the high cost of electricity and the unstable supply of power from renewable sources. The matching and compatibility issues between hydrogen production units and fluctuating power sources pose new challenges to the stable operation of these devices, directly or indirectly hindering the industrialization of hydrogen production via seawater electrolysis. At the same time, the overall cost of producing hydrogen through water electrolysis is high, resulting in a low share of this method in the overall hydrogen production market; there is also a lack of motivation to commercialize seawater electrolysis for hydrogen production. Third, the technologies for producing hydrogen through seawater electrolysis, as well as the safety standards and regulations related to it, are not yet perfect. Compared to conventional electrolytic water splitting for hydrogen production, direct electrolysis of seawater for hydrogen production has a greater tolerance for the quality of the raw materials used; however, it is necessary to establish maximum thresholds for different impurities in order to ensure the standardized development of this industry. To address the above issues, experts offer the following suggestions: First, taking the R&D institutions of large state-owned energy enterprises as the core, and relying on key laboratories, major scientific and technological projects, and significant research initiatives, large-scale application demonstration cases should be developed to accelerate the large-scale research and development of technologies for producing hydrogen through the direct electrolysis of seawater. Second, ensure a stable supply of green electricity through multiple channels. Increase research on the stable supply of green electricity, establish interconnection mechanisms between marine and land-based power grids in coastal areas, and rely on the complementary use of wind, hydro, and solar energy to ensure a stable power supply for hydrogen production. Combining a stable supply of green electricity with energy storage enables stable power supply for hydrogen production facilities and reduces the costs associated with grid connection. Third is to establish standards and norms. Establish and improve the relevant standards and regulatory frameworks for technology and security to promote the healthy development of the industry ； Establish databases on seawater quality in different regions to create region-specific, customized technology libraries for seawater electrolysis-based hydrogen production, thereby enhancing the flexibility of technology application. Looking to the future, Sinopec Dalian Research Institute will continue to work with Qingdao Refining & Chemical to advance the industrial and large-scale application of seawater-based hydrogen production, build demonstration facilities, and explore technical approaches for utilizing green electricity generated in coastal areas and at sea through hydrogen technology, as well as for the recycling of high-salinity wastewater from petrochemical enterprises.