糖心原创

Recently published research from the School of Chemistry has demonstrated a new approach to trapping hydrogen within porous hybrid materials. The research from the groups of Professors Schröder and Champness, reported in the October issue of Nature Chemistry (2009, 1, 487), describes a new method of designing materials called metal-organic frameworks, or MOFs, that facilitates what is known as hysteresis in the hydrogen adsorption properties of the material.

The current impediment to MOFs being used in real-world applications, notably as a hydrogen store for the automobile industry, is the temperature at which MOFs store hydrogen gas, typically -196 °C. Such low temperatures are needed because of the relatively week interactions between the hydrogen molecules and the host MOF. The new research by Schröder and Champness describes how an anionic MOF can be prepared such that charge-balancing cations sit within the channels. By using the correctly-sized cation within the MOF channel the cation essentially acts as a cork trapping guest molecules, in this case hydrogen, from moving in and out of the pore. In this way, hydrogen can be pushed into the MOF at higher pressures and is only released as the pressure is lowered sufficiently opening the cork and allowing the gas to escape. In practical terms this means that hydrogen can be stored at higher temperatures.

 “This novel approach represents a significant advance in methods of trapping hydrogen within MOFs,” Champness told us. “The research offers a potential strategy for taking these systems towards their ultimate application as hydrogen stores for automobile applications but it is necessary to point out that we are not there yet; there is still a lot of work to be done.”