Scientists from RTU MIREA, RUDN University, and Kurchatov Institute have created unusual materials capable of capturing and retaining methane, hydrogen, and water vapor molecules. Researchers compare them to "molecular sponges": the materials can absorb molecules and then release them back when conditions change.

The development is based on high-entropy metal-organic frameworks made from rare earth elements. In the new materials, several rare earth elements simultaneously enter a single crystal structure, forming a high-entropy metal-organic framework.

Scientists used combinations of five, six, and seven rare earth elements. One of the variants included samarium, europium, gadolinium, terbium, dysprosium, holmium, and erbium.

Tests showed that such multicomponent structures absorb methane and especially water vapor better than simple analogues. In addition, the materials proved to be more resistant to chemical exposure.

It is the ability to selectively capture molecules that makes the development interesting for practical applications. Such adsorbents can potentially be used for gas storage and separation, water purification, and catalysis.

At the same time, scientists for the first time demonstrated the possibility of creating high-entropy metal-organic frameworks based not on transition but on rare earth elements. According to the researchers, this approach expands the possibilities for creating high-entropy materials based on rare earth elements.