Catalytic hydrogen production via dry reforming of methane over Ni/Ce _0.65Hf_0.25M_0.1O_2-δ (M = Tb, Sm, Nd, Pr and La)

Ni/Ce_0.65Hf_0.25M_0.1O_2-δ (Ni/CH-M, M = Tb, Sm, Nd, Pr, and La), Ni-based catalysts supported on CeO ₂-HfO₂ materials incorporated with rare earth elements, were prepared by a solvothermal method. The resulting catalysts were found to have surface areas ranging from 41 to 47 m²/g, and they proved to possess strong metal-to-support interactions, as evidenced by temperature programmed reduction analyses. Upon utilization of these catalysts for dry reforming of methane (DRM) with a CH₄/CO₂ ratio of 1 at a range of 600 to 900 C, the Ni/CH-M catalysts were found to have higher activities than the Ni/CH catalyst. In addition, the activities proved to increase in the order of Ni/CH-Pr > Ni/CH-La ~ Ni/CH-Tb > Ni/CH-Nd ~ Ni/CH-Sm > Ni/CH. With a high CH₄/CO₂ ratio of 2, these Ni/CH-M materials showed better stabilities than the Ni/CH catalyst in the DRM reaction at 800 C for 150 h. Moreover, the Ni/CH-M (M = Pr, Tb, and La) catalysts exhibited superior durability over other Ni materials. Consistent with the observations, transmission electron microscopy further confirmed that no carbon species were observed in the Ni/CH-M (M = Pr, Tb, and La) catalysts following the reforming reactions. Graphical Abstract: [Figure not available: see fulltext.]