Poisoning-Resistant Complete Hydrogenation of Liquid Organic Hydrogen Carriers Over Ni-Based Inverse Catalysts

Efficient hydrogen storage using liquid organic hydrogen carriers (LOHCs) requires catalysts that combine high low-temperature activity with robustness against impure H₂ feeds. Conventional supported Ni catalysts are hindered by strong substrate adsorption and consequent site poisoning. Herein, a Ni based inverse catalyst consisting of CeZrO_x clusters supported on metallic Ni is designed, which achieves >99.9% yield in the complete hydrogenation of diverse LOHCs—including mono-, bi-, and triphenyl-type N-heterocyclic and purely aromatic substrates—at low-temperature of 130°C, exhibiting a 200-fold higher activity than conventional Ni catalysts. Key to this performance is the oxide-induced polarization of Ni atoms (Ni^δ+), creating a thermodynamic stable subsurface reservoir and migration routes for dissociated H* species. Through this hydrogen transport pathway, hydrogen can efficiently hydrogenate the strongly adsorbed LOHCs. The significantly lowered H₂ kinetic order confirms the increased surface H* coverage in this inverse configuration. Decoupling the strong substrate adsorption sites and hydrogenation sites, the inverse configuration prevents self-poisoning, enabling complete hydrogenation using crude H₂ and solvent-free LOHCs. This work highlights the superior substrate generality and complete-hydrogenation capability of the Ni inverse catalyst, establishing such inverse systems as a versatile platform for mild and robust LOHC-based hydrogen storage.