A catalytic cycle that enables crude hydrogen separation, storage and transportation

Industrially, hydrogen production often relies on carbon-based resources, necessitating the separation of hydrogen from impurities such as CO, CO₂, hydrocarbons and N₂. Traditional purification methods involve complicated and energy-intensive sequential conversion and removal of these impurities. Here we introduce a reversible catalytic cycle based on the interconversion between γ-butyrolactone and 1,4-butanediol over an inverse Al₂O₃/Cu catalyst, enabling efficient hydrogen separation and storage from crude hydrogen feeds. This process could transform crude hydrogen feeds containing over 50% impurities into pure hydrogen at low temperature. The low impurity affinity and high dispersion of inverse Al₂O₃/Cu facilitate catalytic crude and waste hydrogen separations previously considered unachievable. This approach avoids the need for expensive pressure swing adsorption or membrane systems in liquid organic hydrogen carriers, showing great potential for large-scale applications in crude hydrogen or industrial tail gas utilization processes. By providing a low-risk, energy-efficient alternative, this strategy supports the global transition from grey/blue hydrogen to green hydrogen.