3D-MOF composite offers H2 storage possibilities

Scanning electron micrograph showing the inorganic MOF crystal within an amorphous polymer matrix. Scale bar: 10 μm. Credit: Polymers Advanced Technologies

The only technologically viable method to store hydrogen is to liquefy it, as hydrogen requires impractical cryogenic temperatures for liquefaction. One major alternative is to store hydrogen within metal-organic framework materials (MOFs). One of the first of these materials to be studied for hydrogen storage is MOF-5, which is built around zinc ions and benzodicarboxylate ions. Now, a group led at American University has made a major technological leap in the processing of these materials by three-dimensionally (3D) printing a composite of acrylonitrile butadiene styrene (ABS) and MOF-5.

The group produced a range of composites with MOF mass percentages ranging from 1% to 10%. Larger amounts of MOF led to clumping and undesirable phase separation.

The MOF-5 was found to have undergone degradation due to humidity even before its incorporation into the composite, which may have led to a lowering of its hydrogen capacity. Thus, the results are expected to improve with phase pure MOF-5.

Others in the MOF community have responded positively to this work.