Synergistic Cu–Co Sites Enabled Reversible H 2 Storage and Release in Liquid Organic Hydrogen Carriers

ABSTRACT Liquid organic hydrogen carriers (LOHCs) offer a practical platform for reversible hydrogen storage, a critical bottleneck in the global transition to clean energy. However, their reliance on noble‐metal catalysts and separate catalysts for hydrogenation and dehydrogenation cycles remains a major barrier to practical deployment. Here, we report an earth‐abundant, heterostructured ternary oxide catalyst (CuCoCeO x ) that enables efficient, reversible, and bidirectional hydrogenation–dehydrogenation of LOHCs such as carbazoles over multiple cycles without any pretreatment. Driven by the in situ reaction‐induced reconstruction, the catalyst dynamically evolves and stabilizes functionally decoupled Cu( δ + )–CoO x interfacial sites, where the defective, amorphous CoO x nanodomains anchor bulky LOHC substrates, complementing adjacent Cu sites for reversible hydrogen shuttling. Detailed characterizations and comparison with CuCeO x and CoCeO x reveal the indispensable synergy between coexisting Cu and Co sites. Reduced Cu species facilitate the generation of low‐valence Co sites, while Co species suppress the over‐reduction and sintering of Cu, collectively stabilizing abundant Cu( δ + )–CoO x interfacial sites as the catalytically active centers. This dynamic structural reconstruction delivers 98.4% H 2 uptake and near‐quantitative H 2 release, with stable performance over five consecutive LOHC cycles, substantially surpassing commercial noble‐metal benchmarks.