The core preparation method for hydrogen-oxygen generators is water electrolysis. Its working principle involves using low-voltage direct current to electrolyze water (H2O) to generate a mixture of hydrogen and oxygen (i.e., Brownian gas). This process is typically carried out in an electrolytic cell containing electrolytes such as potassium hydroxide (KOH) or sodium hydroxide (NaOH), and consists of a power module, electrolytic cell, gas-liquid separation system, and safety control device.
Water electrolysis for hydrogen production mainly includes alkaline electrolysis (AE), proton exchange membrane electrolysis (PEME), and solid oxide electrolysis (SOE). Among these, SOE technology uses steam electrolysis, operates at high temperatures, and theoretically has the highest energy efficiency, but this technology is still in the laboratory research and development stage.
In my country, the industrial application of water electrolysis technology is characterized by AE as the main method and PEME as a supplementary method. my country holds a significant share of the global market for alkaline electrolysis (AE) hydrogen production equipment. With renewable energy-based water electrolysis for hydrogen production expected to become the mainstream method in the future, alkaline water electrolysis hydrogen production technology is gradually developing towards larger capacities. MW-level PEME hydrogen production equipment is currently under development and is expected to be launched on the market within 1-2 years.
Regarding AE hydrogen production technology, the focus is on developing highly active, long-life hydrogen and oxygen evolution evolution catalytic electrodes, novel high-gas-resistance, low-resistance, and environmentally friendly membranes; optimizing the flow field structure design of electrolyzers; and developing zero-gap electrolyzers, high-pressure hydrogen production equipment, and large-scale renewable energy hydrogen production systems. Regarding PEME hydrogen production technology, the focus is on developing high-performance, low-precious-metal catalysts, high-durability membrane electrodes, and domestically produced proton exchange membranes; and researching MW-level system integration and gas-thermal management technologies. During the 14th Five-Year Plan period, the focus will be on promoting the demonstration and application of large-capacity AE hydrogen production technology, focusing on tackling key challenges in PEME hydrogen production technology, and strengthening the integrated application of the two technologies and the demonstration of electro-hydrogen systems.
Water electrolysis for hydrogen production has a long history, first realized in 1800, with the first industrial electrolyzer appearing in 1902. Key milestones in modern technological development include: DuPont's improvement of proton exchange membranes in 1962; NEL's introduction of non-asbestos membrane alkaline electrolyzers in 1988; and the development of PEM electrolyzer technology towards MW-level energy products since the 21st century.
