The Future of Green Hydrogen: Challenges and Solutions in Alkaline HER Electrocatalysts

Green hydrogen, renowned for its zero-CO 2 emissions and high energy density, is becoming a hot topic as an alternative to traditional fossil fuels. Scientists have made significant strides in a process called the alkaline hydrogen evolution reaction (HER). This process, used to generate high-purity hydrogen gas in labs, is now driving the development of industrial-scale anion exchange membrane water electrolyzers (AEMWEs). These new devices are giving tough competition to existing large-scale hydrogen production technologies. However, there's still a lot of ground to cover. Researchers face challenges in finding electrocatalysts that are highly active and stable for alkaline HER. Additionally, they need to close the performance gap between laboratory setups (three-electrode cells) and real-world devices (AEMWEs). Let's delve into the inner workings. Activating alkaline HER electrocatalysts involves several in-depth mechanisms. These include electronic modification, constructing defects, controlling the overall shape, synergistic effects, and field effects. On the other hand, the current state of AEMWE and its roadblocks are also reviewed. These bottlenecks limit the application of HER electrocatalysts within AEMWE. Looking ahead, the outlook is promising. Thoughts are shared about the future development directions for electrocatalysts. These improvements aim to advance both alkaline HER and AEMWE technologies, pushing forward the commercialization of water electrolysis for green hydrogen production.