摘要
We develop a new Ni-CeOx hybrid nanoparticle as a high-performance catalyst for dry reforming of methane with carbon dioxide (DRM) using a facile gas-phase synthetic approach. The crystallites of Ni and CeO2 were homogenously self-assembled as a hybrid nanostructure, creating a large amount of Ni-Ce-O interface for a strong metal-support interfacial interaction. Chemical composition and oxidation state of the hybrid nanostructure were tunable directly in the aerosol state. The results show that the starting temperature of catalysis by Ni-based catalysts reduced by ≈ 150 °C through the hybridization with CeO2 followed by a direct H2-reduction in the aerosol state. In comparison to Ni-only nanoparticle, the Ni-CeOx hybrid nanoparticle showed stable and high conversion for CH4 and CO2 with a remarkably turnover frequency at low temperature (0.1 s-1 at 450 °C). The amount of coke formation greatly reduced by 18×, whereas the H2/CO ratio was constant at ≈ 0.8 by a 1.5× of the increase of CO2/CH4 ratio. The work demonstrated a facile route for controlled synthesis of Ni-CeOx hybrid nanoparticles with a very high catalytic activity and stability of DRM. The findings of this study can shed a light on the mechanism of Ni-Ce-O synergistic catalysis, which can be especially useful for methane-based energy applications.