Dynamic Self-Healing of Nickel Catalysts via Hydrogen Spillover for Efficient Hydrogenation

The practical use of nickel catalysts is severely limited by surface oxidation, which passivates active sites with a NiO layer, resulting in a debilitating induction period. While protective strategies exist, they inevitably compromise the accessibility and intrinsic activity of Ni sites. Herein, we introduce a paradigm shift from static protection to dynamic self-healing via hydrogen spillover in a Ni-Pd/CeO 2 architecture. Trace Pd (0.2 wt %) acts as efficient hydrogen-dissociation centers, from which active hydrogen species migrate via the CeO 2 support to continuously reduce the passivating NiO layer in situ. This process dynamically exposes metallic Ni 0 sites under operation, which function as the primary centers for furan ring activation. In contrast to the conventional Ni/CeO 2 catalyst, which suffers from a debilitating induction period, the Ni-Pd/CeO 2 system achieves an activity enhancement of 55-fold in TOF for the hydrogenation of furfuryl alcohol to tetrahydrofurfuryl alcohol. Combined spectroscopic and kinetic experiments, including H 2 -TPR, H−D exchange, Pd loading optimization, and support effect studies, corroborate the hydrogen spillover mechanism. This work represents a paradigm shift from conventional static protection strategies to dynamic self-healing mechanisms, establishing a general blueprint for designing self-sustaining non-precious metal catalysts, paving the way for their use in cost-efficient catalytic processes.