An immature pinecone shaped hierarchically structured zirconia (ZrO 2 -ipch) and a cobblestone-like zirconia nanoparticulate (ZrO 2 -cs), both with the monoclinic phase (m-phase), were synthesized by the facile hydrothermal method and used as the support for a Ni catalyst for the dry reforming of methane (DRM) with CO 2 . ZrO 2 -ipch is a much better support than ZrO 2 -cs and the traditional ZrO 2 irregular particles made by a simple precipitation method (ZrO 2 -ip). The supported Ni catalyst on ZrO 2 -ipch (Ni/ZrO 2 -ipch) exhibited outstanding catalytic activity and coke-resistant stability compared to the ones on ZrO 2 -cs (Ni/ZrO 2 -cs) and ZrO 2 -ip (Ni/ZrO 2 -ip). Ni/ZrO 2 -ip exhibited the worst catalytic performance. The origin of the significantly enhanced catalytic performance was revealed by characterization including XRD, N 2 adsorption measurement (BET), TEM, H 2 -TPR, CO chemisorption, CO 2 -TPD, XPS and TGA. The superior catalytic activity of Ni/ZrO 2 -ipch to Ni/ZrO 2 -cs or Ni/ZrO 2 -ip was ascribed to a higher Ni dispersion, increased reducibility, enhanced oxygen mobility, and more basic sites with a higher strength, which were due to the unique hierarchically structural morphology of the ZrO 2 -ipch support. Ni/ZrO 2 -ipch exhibited better stability for the DRM reaction than Ni/ZrO 2 -ip, which was ascribed to its higher resistance to Ni sintering due to a strengthened metal-support interaction and the confinement effect of the mesopores and coke deposition resistance. The higher coking resistance of Ni/ZrO 2 -ipch for the DRM reaction in comparison with Ni/ZrO 2 -ip orignated from the coke-removalability of the higher amount of lattice oxygen and more basic sites, confirmed by XPS and CO 2 -TPD analysis, and the stabilized Ni on the Ni/ZrO 2 -ipch catalyst by the confinement effect of the mesopores of the hierarchical ZrO 2 -ipch support. The superior catalytic performance and coking resistance of the Ni/ZrO 2 -ipch catalyst makes it a promising candidate for synthesis gas production from the DRM reaction.
