Light‐Activated Dual‐Site Pathway Enables Efficient Hydrogen Release From Dodecahydro‐N‐ethylcarbazole

Dodecahydro‐N‐ethylcarbazole (12H‐NEC) is a promising liquid organic hydrogen carrier (LOHC), yet its practical application is still constrained by slow dehydrogenation kinetics and extreme reliance on external heating even over most effective Pd‐based catalysts. Here we identify that the hydrogen removal step with a high barrier is the precise kinetic bottleneck of 12H‐NEC dehydrogenation, which remains underexplored. To effectively overcome this limitation, we report a light‐activated dual‐site hydrogen removal pathway using Pd nanoparticles supported on defective N‐doped TiO 2 . Under irradiation, charge transfer from the support to Pd weakens Pd‐H interactions, while accumulated holes on the support promote hydrogen spillover to Ti defect sites, generating weakened Ti‐H species alongside Pd‐H. This thereby initiates a new hydrogen formation dual‐site pathway by combining Pd‐H and Ti‐H with an overall dehydrogenation barrier of 0.46 eV only, 0.74 eV lower than the conventional thermal Pd‐localized pathway, resulting in a 42‐fold higher H 2 release rate relative to dark conditions at 140°C. Even under concentrated natural sunlight without external heating, near‐complete dehydrogenation with a capacity of 5.65 wt.% H 2 within 1 h is achieved from 12H‐NEC. This work charts a promising course for practical hydrogen storage applications of LOHCs without secondary energy input.