Breaking the Activity-Stability Trade-Off in Dry Reforming of Methane via Heteroenergetic Support Engineering.

Abstract

Nickel-based catalysts are promising for dry reforming of methane (DRM) owing to their high C─H bond activation ability and low cost, while highly susceptible to coke deposition and sintering. Here, we report a heteroenergetic Ce0.75Ti0.25O2-x support that simultaneously regulates Ni nanoparticle stabilization, DRM activity, and oxygen-mediated carbon removal. Neural-network-based molecular dynamics (NN-MD) simulations and electron microscopy show that partial Ti substitution in CeO2 transforms the strong Ni-CeO2 interaction and weak Ni-TiO2 interaction into an intermediate wetting regime with a Ni-support contact angle close to 90°, suppressing both particle migration/coalescence- and Ostwald ripening-induced sintering while preserving a coupled population of active interfacial and metallic Ni sites. Characterizations and Bader charge analysis further reveal that Ce0.75Ti0.25O2-x moderates Ni-support electronic coupling and improves oxygen vacancy concentration and lattice oxygen mobility. These coupled structural and chemical effects facilitate methane activation and transient carbon removal through synergistic Mars-van Krevelen and Langmuir-Hinshelwood pathways. As a result, Ni/Ce0.75Ti0.25O2-x achieves highly competitive DRM performance with near-equilibrium CH4 and CO2 conversions of 93.8% and 94.3%, respectively, at 750°C and remains stable over 120 h without noticeable deactivation. This work establishes heteroenergetic support engineering as an effective strategy that reconciles high activity with long-term stability in thermally demanding catalytic reactions.