Coke-resistant Ni-based bimetallic catalysts for the dry reforming of methane: effects of indium on the Ni/Al2O3 catalyst

Abstract

In the quest for highly efficient coke-resistant catalysts for the dry reforming of methane (DRM) to produce syngas, a series of Ni–In/γ-Al₂O₃ catalysts with various Ni contents were prepared via a “two-solvent” method and used for the DRM reaction. The results reveal that the catalysts with a Ni/In ratio of 3/2 showed the optimal CH₄ and CO₂ conversion activities of 91.1% and 97.1%, respectively. Furthermore, after a 200 hour long-term balancing test at 700 °C, the deactivation factor was 2.55% on Ni–In/γ-Al₂O₃, indicating that the Ni–In/γ-Al₂O₃ catalyst remained stable. Compared to the Ni/γ-Al₂O₃ catalyst, the addition of In increased the surface-adsorbed oxygen species and the oxygen vacancy amounts on Ni–In/γ-Al₂O₃ and increased the CO₂ adsorption capacity, which enhanced the CO₂ conversion by 12.8%. Moreover, the interaction between Ni and In promoted the dispersion of Ni particles and inhibited the agglomeration of Ni during the DRM reaction. In addition, the carbon deposition on the catalyst was also reduced, which greatly improved the stability of Ni–In/γ-Al₂O₃.