LAUSR

Abstract We demonstrated an aerosol-based approach to synthesize Ni-CeO2-Al2O3 hybrid nanostructure as a potent nanopowder catalyst for the production of polyetheramine via reductive amination of polypropylene glycol. The method combines a gas-phase evaporation-induced self-assembly with two-stage thermal treatments of the aerosol particles. The hybrid Ni-CeO2 nanoparticles (NPs) composed of ultrafine, homogeneously-distributed nanocrystallites of metallic Ni and ceria were shown to uniformly decorate on the surface of Al2O3 nanoparticle cluster (NPC). The composition, physical size and surface state of the hybrid nanostructure were tunable by design. It was found that hybridization with Al2O3 or CeO2 enhanced catalytic activity of the Ni catalyst. A high yield of ≈77% of the desired PEA and a high selectivity to primary amine (≈100%) achieved simultaneously. The surface nitridation of Ni catalyst was effectively suppressed via the incorporation with CeO2 NPs. An enhanced operation stability was observed by using the Ni-CeO2-Al2O3 hybrid nanostructure as catalyst in comparison to the Ni-only NP. The work demonstrated a facile route for controlled gas-phase synthesis of hybrid nanopowder catalysts using Al2O3 NPC as the support matrix and CeO2 NP as the promoter to further enhance the performance of Ni catalyst toward reductive amination.