A catalyst that protects itself while producing hydrogen
Cobalt phosphide (CoP) is a promising alternative to platinum for producing hydrogen from water. However, scientists have struggled to explain why it performs so well. Computer models have suggested that CoP should become unstable under the conditions used to produce hydrogen, yet experiments show that it remains active and durable in acidic, neutral and alkaline environments.
Scientists have discovered a new explanation for why cobalt phosphide (CoP) is an effective catalyst for producing hydrogen from water. Despite its promising performance, researchers have struggled to understand why CoP remains stable and active under various conditions. A new study published in the Journal of the American Chemical Society provides insight into this phenomenon: as CoP produces hydrogen, it undergoes changes on its surface that help it maintain performance while protecting itself from damage.
The catalyst responds to the electrical voltage applied during water electrolysis, forming different chemical species on its surface that aid in hydrogen production and prevent breakdown. At lower voltages, hydroxyl groups form on the phosphorus sites, helping cobalt atoms activate water and bind hydrogen more effectively. As the voltage increases, the surface changes again, becoming covered with hydrogen-containing species.
These surface adjustments allow the catalyst to maintain an effective balance between binding and releasing hydrogen across a wide range of pH conditions, while also providing protection against oxidation. The researchers used a combination of AI-assisted analysis, computer simulations, and laboratory experiments to investigate this process.
Their findings could lead to more affordable and versatile catalysts for green hydrogen production, emphasizing the importance of considering surface changes in catalyst design.
Brief written by urgent.news from Phys.org's own syndicated text. Machine-written — may contain errors; check the original before relying on it.
