Stabilizing Nickel-Based Catalysts for Ethanol Dry Reforming via Dual-Oxide-Metal Interface Establishment: Combination Studies of In Situ Insights and Microkinetic Investigations

Ethanol dry reforming (EDR) provides an attractive route for syngas production, yet it is limited by unresolved questions surrounding active sites and reaction mechanisms. Here, we report a dual-oxide/metal-interface Ni/CeO 2 @TiO 2 catalyst fabricated by atomic layer deposition that delivers high activity, selectivity, and long-term stability for EDR. Specifically, the catalyst achieves almost quantitative conversion over ethanol (∼100%) and CO 2 (∼85.4%), with 94.6% CO selectivity and sustained performance over 300 h without detectable deactivation. More importantly, we introduce two independent descriptors, c.a. λ and μ, to quantify the extent of C−C bond cleavage and the completeness of EDR, respectively, thereby providing a unified metric for evaluating EDR performance. Clearly, the C−C bond rupture and reforming was dominated by the particle size of Ni, the oxygen vacancy of the adjacent oxide, the reduction degrees of Ni and the in situ generated Lewis acid sites. In situ infrared spectroscopy, X-ray absorption fine-structure spectroscopy, and kinetic analysis reveal that catalysis of EDR is dominated by interfacial sites within Ni-CeO 2 /TiO 2, where strong metal-support interactions regulate surface electronic structure, adsorption behavior, and reaction pathways. The TiO 2 overlayers suppress metal sintering, enhance interfacial site density, and promote CO 2 activation together with oxidative carbon removal, certainly that the balancing hydrocarbon activation and carbon oxidation governs both activity and the stability.