Strengthening the Metal–Support Interaction by Mo–Ni Bimetallic Nanoparticles with Ce _{1– x} Ti _x O ₂ Solid Solution for Boosting Photothermal Methane Dry Reforming Reaction

Photothermal methane dry reforming (PT-DRM) provides a sustainable pathway for syngas production by harnessing solar energy, yet its efficiency is often limited by metallic sintering and carbon deposition. This work develops an innovative Mo–Ni bimetallic nanoparticle catalyst supported on Ce 1– x Ti x O 2 solid solution to overcome these barriers. The formation of a Ce 1– x Ti x O 2 solution introduces intermediate impurity levels that extend the optical absorption edge and significantly enriches surface oxygen vacancies. The photoexcitation via these localized impurity levels provides a steady flux of charge carriers that synergizes with thermal energy to dramatically enhance CH 4 and CO 2 conversions. The optimized Mo–Ni/Ce 0.97 Ti 0.03 O 2 catalyst successfully approaches the thermodynamic equilibrium conversion limits even under an exceptionally severe space velocity of GHSV = 120,000 mL/(g·h) at 973 K, highlighting its rapid intrinsic reaction kinetics. The synergy between photogenerated charge carriers and abundant lattice oxygen is suggested to effectively gasify carbon precursors, limiting carbon deposition to a remarkable 0.5 wt %, lower than that from thermal catalysis. By bridging support defect engineering with bimetallic electronic modulation, this study establishes a rational strategy to design stable and efficient catalysts for greenhouse gas valorization.