Efficient MOF-Catalyzed Ortho–Para Hydrogen Conversion for Practical Liquefaction and Energy Storage

Parahydrogen, being one of two nuclear spin isomers of molecular hydrogen, is required in a number of applications, including hydrogen liquefaction for energy storage and transportation. Obtaining pure parahydrogen is vital for these tasks, thus requiring approaches for efficient ortho–para (OP) hydrogen conversion. In this work, we for the first time demonstrate the extraordinary potential of metal–organic frameworks (MOF) as OP-conversion catalysts. In particular, the specific conversion rate constant of Ni-MOF-74 is found 145-fold higher than that of industrially used catalysts (e.g., hydrous ferric oxide), thus opening new horizons in hydrogen liquefaction and storage and, ultimately, in the broad use of hydrogen energy.