New green hydrogen recipe: aluminum, caffeine, and salt water

Put aluminum powder in water, and it reacts vigorously, freeing hydrogen gas and producing metal hydroxide and heat. Researchers are now getting closer to a low-cost, sustainable way of using this reaction to produce green hydrogen fuel ( Cell Rep. Phys. Sci. 2024, DOI: 10.1016/j.xcrp.2024 .102121 ). The aluminum–water reaction splits water without using electricity . The challenge is that aluminum instantly forms a protective aluminum oxide skin in air that keeps it from reacting with water. “This is why, when you put a soda can in water, it doesn’t react,” says Aly Kombargi , a mechanical engineering PhD student at the Massachusetts Institute of Technology. In 2018, MIT researchers found that coating aluminum pellets with a liquid metal alloy of gallium and indium perforates the oxide skin, creating channels for water to reach the aluminum interior. The pellets react with water, and the reaction consumes the aluminum, giving a