Enhancement of CO₂ activation and coke-resistant ability on Ni/CeO₂ catalyst with La doping for dry reforming of methane

In the dry reforming of methane (DRM), the oxygen vacancies on the surface of Ni/CeO₂ catalyst play an important role in CO₂ activation, catalytic performance and coke resistance. Herein, Ni/CeO₂ catalysts doped with different amounts of La were investigated to reveal the relationship between oxygen vacancies and catalytic behavior. The addition of La leads to the reduction in size of Ni particles and stronger metal-support interaction (SMSI). Furthermore, the highest proportion of oxygen vacancies is found in 10 wt% La doped Ni/CeO₂ catalyst, which is beneficial for CO₂ activation and CH₄ dissociation. The Ni/CeLa10 catalyst shows stable methane conversion during 100 h of stability test, which is maintained at 80% without obvious decrease at 750 °C. Therefore, the catalysts with more oxygen species display outstanding activity for the DRM and assisted ability in carbon resistance. This work aims to provide a molecular understanding of the modification of DRM's inherent surface sites.