Structural evolution of Ni-Ce bimetallic alloy on Al2O3 support in methane dry reforming: Achieving sustainability and high-efficiency reaction through cerium modulation strategy

• Optimized Ni-Ce bimetallic alloy structure for enhanced low temperature reduction performance. • Achieved 98.34 % CH 4 conversion with 10 wt% Ce (800 °C), outperforming Ni@Al 2 O 3 . • Enhanced crystallinity and accessibility of active sites through Ni-Ce synergy. • Identified CO 2 dissociation at high temperatures (>750 °C) as a crucial reaction step. • Ce regulation promoted reactant adsorption/dissociation while inhibiting carbon deposition for long-term stability. This research delves into the methane dry reforming, meticulously exploring the structural-evolution of Ni-Ce bimetallic alloy on Al 2 O 3 support during the reaction-process and its impact on catalytic performance. By delicately tuning the cerium content to an optimal proportion of 10 wt%, we achieved a remarkable optimization of the catalyst structure, fostering the low-temperature reduction of nickel-species and an increase in oxygen-vacancies. At 800 °C, this optimized catalyst exhibited a methane conversion as high as 98.34 % (maintained for 50 h), significantly outperforming the Ni@Al 2 O 3 . Our findings revealed that the synergistic-interaction between the Ni-Ce bimetallic properties and the hydrogen-reduction-process enhanced the crystallinity and accessibility of active-sites within the catalytic. In-situ DRIFT spectroscopy and thermogravimetric analysis demonstrated that the adoption of a cerium modulation strategy markedly enhances the adsorption and dissociation efficiency of reactants, while effectively mitigating the formation of carbon deposition during extended reaction periods. Consequently, this ensures that the catalyst maintains exceptional activity throughout a continuous 50-hours operation. This study expands the new adsorption and carbon-accumulation mechanism in the methane dry reforming and lays a solid-foundation for its industrial application.