Controlled synthesis of ceria nanoparticles for the design of nanohybrids

Ceria nanoparticles were synthesized from reaction mixture of cerium nitrate/hexamethylenediamine/water–ethylene glycol. Lamellar, particle-aggregated array, platelet, rice, cube, quasi-sphere shapes of the ceria nanoparticles can be controlled by tuning reaction parameters (reagent concentration, reagent components, pH, and reaction conditions). Studies on shape-dependent catalysis of the bare ceria samples toward CO oxidation indicated that the cube-shaped ceria nanoparticles show better catalytic activity than the nanospheres and the commercial micropowders. As capped by hexamethylenediamine (HEA) molecules, amine-functionalized ceria nanoparticles act as platforms for depositing copper particles to produce efficient Cu/CeO2 hybrid nanocatalysts for CO conversion. Coupling of the copper clusters with the HEA-capped ceria nanocubes was achieved with the Cu contents up to 15 wt.%. The Cu/CeO2 nanohybrids show an enhanced catalytic efficiency of low temperature CO conversion. This could be due to high exposure of the reactive {1 0 0} facets in the ceria nanocubes and interfacial copper–ceria interactions.

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► Shape-controlled synthesis of lamellar, array, platelet, rice, cube, quasi-sphere nanoceria.
► Shape-dependent catalytic activity of bare CeO2 nanoparticles for CO oxidation.
► Amine-functionalized nano-ceria as platforms for synthesis of Cu/CeO2 nanohybrids.
► Cu particle size-sensitive catalytic activity of Cu/CeO2 nanocubes for CO oxidation.