Please login first
The annealing effect of structured nickel octahedra nanoparticles on the performance of NiO supported on silica in combined steam and dry reforming of a model biogas mixture
* 1 , 2
1  American University of the Middle East
2  Laboratoire de Réactivité de Surface, Sorbonne Université, Campus UPMC, CNRS, UMR 7197, 4 place Jussieu, Paris, 75005, France
Academic Editor: Jian-Gan Wang (registering DOI)

The octahedral family of NiO nanoparticles is gaining significant attention as an assembly with unique physicochemical properties and outcomes in electromagnetics, shielding, and absorption. In this study, a mesoporous structured Ni60%SiO2(Comm), chosen owing to its NiO species existing in an octahedral shape, was evaluated for synthesis gas (syngas: H2(g) and CO(g) mixtures) production via combined steam and dry reforming of a model biogas mixture (T= 800 °C, (H2O(g) + CO2(g))/CH4(g)= 1.2). To the best of our knowledge, the consideration of Ni octahedra-based nanomaterials as potential catalysts for reforming reactions, particularly biogas reforming, towards syngas generation has not been yet considered in the available literature. In comparison to a standard Ni5%SiO2 catalyst, slightly higher reactivity levels along with significantly lower amounts of carbonaceous deposits were obtained over the commercial Ni60%SiO2(Comm) catalyst for 10 h on stream. The high coke resistance of originally shaped NiO octahedra was ascribed to an annealing effect, generated during H2(g)-treatment (prior to catalysis), yielding mesoporous metallic Ni0 nanorods with H2(g)-storage capacities. Stored hydrogen within Ni0 layers acted as active centers for continuous in situ coke gasification, preventing thus C(s) accumulation while keeping Ni0 sites accessible for catalysis.

Keywords: Octahedral nanoparticles; Biogas reforming; Annealing effect; Carbon gasification