Main group catalysis for H ₂ purification based on liquid organic hydrogen carriers

Molecular hydrogen (H₂) is one of the most important energy carriers. In the midterm future, a huge amount of H₂ will be produced from a variety of hydrocarbon sources through conversion and removal of contaminants such as CO and CO₂. However, bypassing these purification processes is desirable, given their energy consumption and environmental impact, which ultimately increases the cost of H₂. Here, we demonstrate a strategy to separate H₂ from a gaseous mixture of H₂/CO/CO₂/CH₄ that can include an excess of CO and CO₂ relative to H₂ and simultaneously store it in N-heterocyclic compounds that act as liquid organic hydrogen carriers (LOHCs), which can be applied to produce H₂ by subsequent dehydrogenation. Our results demonstrate that LOHCs can potentially be used for H₂ purification from CO- and CO₂-rich crude H₂ in addition to their well-established use in H₂ storage.