Alloy-vacancy engineering evolved from Al–OH anchored NiCo layered structure enables durable methane dry reforming

Alloying Ni with another metal on γ-Al 2 O 3 support holds considerable promise to enhance carbon-resistance in dry reforming of methane (DRM), yet its effectiveness is constrained by poorly controlled alloy structure and surface Al-OH groups. Herein, bimetallic NiCo/γ-Al 2 O 3 catalysts were designated using electropositive NiCo complexes via a strong electrostatic adsorption strategy. The NiCo alloy and oxygen vacancy were primarily derived from the evolution of surface Al- μ 2 -OH and Al- μ 3 -OH groups anchored NiCo layered structures. The optimized Ni 3.0 Co 3.0 Al catalyst achieved near-thermodynamic-equilibrium CH 4 and CO 2 conversions, along with ultra-low coke deposition rate (0.03 mg coke ·g cat −1 ·h −1 ) after 200 h on-stream at 600°C. Microkinetic and in situ FTIR studies elucidated the reaction mechanism, wherein CH x * species from CH 4 decomposition on atomically uniform NiCo alloys were rapidly eliminated by surface Al–OH and reactive O* generated from CO 2 dissociation on limited oxygen vacancies, forming labile HCOO* and CH x O* intermediates, while effectively suppressing the Boudouard reaction, thereby ensuring exceptional catalyst longevity.