column.
3 Results and discussion
3.1 Characterization of Ni-B/CNTs catalysts
As shown in Fig.1(a), carbon nanotubes treated by
ammonia entangle each other and most Ni-B alloys are in
the form of highly aggregation except for a few high
dispersion particles on nanotubes. Adsorption of Triton
x-100 on carbon nanotubes treated by ammonia, however,
results in relatively individual nanotubes and
homogeneous Ni-B particles with mean size about 10 nm
on nanotubes, as shown in Fig.1(b).
In order to confirm the amorphous structure of
prepared catalysts, XRD measurement was performed.
As shown in Fig.2, the XRD patterns of carbon
nanotubes indicate the graphite structure of prepared
sample. Cubic nickel was still presented in carbon
nanotubes after they were treated with ammonia. The
nickel could be assigned to the Ni residue from the Ni-
Fig.1 TEM images of catalysts: (a) Ni-B/CNTs; (b) Ni-B/
CNTs-T
Fig.2 XRD patterns of samples
Cu-Al catalyst, used to synthesize CNTs. From this, it is
likely that nickel residue in CNTs is difficult to remove
by heat treatment with ammonia. Compared with the
patterns of CNTs, the patterns of Ni-B/CNTs and
Ni-B/CNTs-T do not exhibit other crystalline peaks,
which means the amorphous structure of prepared
HU Chang-yuan, et al/Trans. Nonferrous Met. Soc. China 17(2007) s1105
catalysts[14].
The bulk composition, Ni-loading, total surface area
and active surface area of the fresh catalysts are listed in
Table 1. Ni-loading is increased approximately by 14.6%
through adsorption of Triton x-100 on carbon nanotubes
treated by ammonia. The reason may be that
modification of CNTs with Triton has effects on the
stabilization of nanotubes suspension and the wetting
behavior of nanotubes surface. These changes facilitate

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