The rational design of advanced catalysts for CO₂ methanation remains a significant challenge, while Ni-based catalysts hold considerable promise for industrial applications owing to their high catalytic performance and low cost. Herein, we systematically investigate the regulation of active-site environments across a series of Ni-based catalytic systems, aiming to establish a unified structure–performance relationship. A consistent picture emerges, revealing that the intrinsic catalytic activity is governed by the synergistic interplay of the Ni–support interfacial perimeter, the Ni⁰/Ni²⁺ ratio, and surface basicity, which collectively regulate H₂ activation, CO₂ adsorption, and the evolution of surface intermediates. Ce substitution in perovskite lattices weakens the Ni–O bond and promotes the in situ exsolution of Ni⁰ species, generating a stable yet reactive interface that facilitates both H₂ dissociation and CO₂ activation. The morphology of hydrotalcite-derived supports further modulates metal–support interactions, with plate-like architectures maintaining an optimal Ni⁰/Ni²⁺ ratio favorable for CO₂ conversion. Ru incorporation enhances low-temperature kinetics through hydrogen spillover, whereas Fe modifies the electronic structure of Ni and tunes the adsorption energetics of key *HCOO and *CH₃O intermediates, thereby facilitating their hydrogenation. Studies over Ni/CeO₂ further demonstrate that the interfacial perimeter, rather than Ni crystallite size alone, is a key determinant of structure sensitivity. Complementary spectroscopic and kinetic analyses provide evidence for a dynamic “route-refresh” process involving H-spillover-induced oxygen vacancies and regeneration of reactive interfacial sites. Collectively, these findings establish synergistic site-environment engineering as a general design principle for developing highly active and stable Ni-based catalysts for low-temperature CO₂ methanation.

Ni-based catalysts,CO2 methanation,Active sites,Ambient Pressure,Strong metal–support interactions