Size-controllable Ni5TiO7 nanowires as promising catalysts for CO oxidation

Ni 5 TiO 7 nanowires with controllable sizes are synthesized using PEO method combined with impregnation and annealing at 1050 o C in air, with adjustment of different concentrations of impregnating solution to control the dimension of nanowires. The resulting nanowires are characterized in details using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analysis. In addition, the CO catalytic oxidation performance of the Ni 5 TiO 7 nanowires is investigated using a fixed-bed quartz tubular reactor and an on-line gas chromatography system, indicating that the activity of this catalytic system for CO oxidation is a strong dependency upon the nanocrystal size.When the size of the Ni 5 TiO 7 nanowires is induced from 4 μm to 50 nm, the corresponding maximum conversion temperature is lowered by ~100 o C.