Pt(NH
3
)
4
(NO
3
)
2
,
Pt(NH
3
)
4
(Ac)
2
, (NH
4
)
2
PtCl
4
, and H
2
PtCl
6
were used
to prepare Pt/SAPO-11 catalysts to investigate the effect of Pt precursors
on the hydroisomerization of
n
-dodecane. The catalyst
derived from Pt(NH
3
)
4
(NO
3
)
2
displays the best hydroisomerization activity and selectivity among
these precursors. The hydroisomerization conversion of
n
-dodecane is affected by the platinum particle size, platinum dispersion,
the location of platinum, and the valence state of platinum. The selectivity
of
n
-dodecane is determined by the number of Brønsted
acid sites and Pt crystal planes. These conclusions are verified by
combining transmission electron microscopy, high-resolution transmission
electron microscopy, hydrogen temperature programmed reduction, NH
3
-temperature programmed desorption, and Py-IR studies. The
catalyst prepared with Pt(NH
3
)
4
(NO
3
)
2
as the precursor exhibits the smallest platinum particle
size and the highest platinum dispersion. Most of the platinum particles
are supported on the external surface of SAPO-11 with the Pt(111)
crystal face. Such a catalyst also possesses a suitable number of
Brønsted acid sites and then displays the best catalytic performance.
Obviously, the use of various precursors for the Pt-based catalyst
can significantly affect the performance of Pt/SAPO-11 for the hydroisomerization
of
n
-dodecane.