3
8
P. Zhang et al. / Journal of Fluorine Chemistry 186 (2016) 33–39
Because of the existence of “cavities” in the space lattice of solids
and the strong field around the molecules of FeF , ZrF , Co(ZrF
and CuZrF , ZFZCC catalyst tended to adsorb Cl /HF molecule
rapidly [35]. However, Cl /HF molecules must pack themselves
and surface areas were determined by Brunauer-Emmett-Teller
(BET) method.
3
4
6
)
19F NMR spectra were recorded on a Bruker AV400 instrument
6
2
2
3
at 376 MHz with CFCl as an internal standard.
into the space lattice cavities with enough compression in the
reaction process.
Gas chromatography–mass spectroscopy (GC–MS) was con-
ducted using a Shimadzu-QP 2010 Ultra series system equipped
with a jet separator for the 2010 GC. The capillary column was DB-
5 with 0.25 mm i.d. and 30 m length (J&W Scientific Inc.).
Gas chromatography (GC) was used and its operation condition
was as follows: capillary column, DB-5 with 0.25 mm i.d. and 30 m
AHF, as an important vapor-phase fluorinating agent, is
speculated to be activated through an intermediary HF oligomer
on chrome-based catalyst (CrFꢂ ꢂ ꢂ(HF)ꢂ ꢂ ꢂHX (X = F or Cl)), and the
active catalytic atom is situated at the end of the oligomer [36].
This hypothesis was confirmed by Clark et al. [37], who reported
that the end-fluorine of an oligomer was more labile. Therefore, the
same type of oligomer may exist in this process even at high
temperatures.
ꢀ
length (J&W Scientific Inc.); column temperature, 35 C for 3 min
ꢀ
ꢀ
ꢀ
and heated to 200 C at a rate of 10 C/min, then 200 C for 3 min;
ꢀ
ꢀ
injector temperature, 280 C; detector temperature, 200 C; split
ratio, 80:1; and sample size, 0.1 l.
m
Steric effect is also an important factor in the fluorination
reaction. From the stereochemical points of view, we can easily
understand the reaction pathways. As for route 2 !10 ! 3/4, when
Scanning electron microscope (SEM) images of the catalysts
were obtained using a Shimadzu SS-550.
The apparatus for the vapor-phase fluorination reaction was
2
, AHF and Cl
2
were exposed to the ZFZCC catalyst bed, Cl
2
addition
composed of a pump for offering reactant (liquid phase), Cl
2
, AHF,
reaction occured first and then 3 and 4 were generated by Cl/F
exchange reaction. Meanwhile, 7 was produced by fluorinating 3
and 4. The explanation stated above is depicted in Fig. 4a and b.
Because of steric effect, 3 and 4 should be obtained equivalently.
However, the yield of 4 was generally higher than that of 3 which
could be explained by route 2 ! 5 ! 8 ! 4 (Fig. 4c). Fig. 4d
illustrates transition metal catalytic mechanism. As the reaction
proceeded, valence of the transition metal decreased, resulting in
the loss of catalytic activity. Meanwhile, transition metal was
N mass flow controllers, and an electrically heated tubular Inconel
2
reactor (14 mm in diameter and 300 mm in length) that was
equipped with an inner Inconel tube for inserting type-K
thermocouples with a 1-mm diameter. A thermocouple entered
the reactor through a Monel-type fitting and extended into the
catalyst bed to measure the temperature changes in different
positions along the reactor.
4.3. Preparation of catalysts
2
oxidized by Cl , the valence then increased, and the catalyst
regained its catalytic activity.
4.3.1. Preparation of active charcoal
Active charcoal was typically pretreated as follows.
A
3
. Conclusion
1000 ml glass flask was initially charged with 50 g active
2
charcoal, with a size of 20–40 mesh screens and ꢃ1000 m /g
1
,1-Dichlorooctafluorocyclopentane and 1,2-dichlorooctafluor-
ocyclopentane were prepared through the reaction of 1,2-
dichlorohexafluorocyclopentene, AHF and Cl . A series of single-
and multi-component catalysts were then prepared and tested for
synthesizing 1,1-dichlorooctafluorocyclopentane and 1,2-dichlor-
ooctafluorocyclopentane. Multi-component catalyst containing Fe
surface area. Afterward, 300 ml HNO
3
(10%) was added
gradually. Slurry was stirred with an electric stirrer at
300 r/min for 10 h. Subsequently, the slurry was filtered and
washed several times with de-ionized water until pH was about
2
ꢀ
7. Finally, the slurry was dried at 100 C for 12 h in a drying
oven, and an active charcoal was obtained.
(
III), Zr(IV), Co(II), Zn(II) and Cu(II) have high catalytic activity.
Compared with other catalysts, the coprecipitated ZFZCC catalyst
was more active. Moreover, the reaction routes for the synthesis of
4.3.2. Catalysts prepared by an impregnation method
Pretreated active charcoal was impregated into a FeCl
(about 3 wt.%) for 12 h, and the loading amount of FeCl was about
1 wt.% on the active charcoal. Calcination was then conducted at
3
solution
3
and 4 from 2 in the presence of ZFZCC were disscussed and the
3
main routes were proposed. Catalytic mechanism was reported
from the aspects of crystalline phase structure, BET surface area
and sterical effect.
ꢀ
ꢀ
250 C for 10 h (rate of N
2
: 150 ml/min) and 400 C for 10 h (rate of
N
2
: 200 ml/min). Afterward, 20 g catalyst was packed into the
ꢀ
reactor and dried at 200 C for 2 h under N
AHF was passed through the reactor at 250 C for 10 h (N
AHF = 50: 100 ml/min); 250 C for 10 h (N
and 450 C for 10 h (N
2
. The mixture of N
2
and
ꢀ
4. Experimental
2
:
ꢀ
2
: AHF = 0:150 ml/min);
ꢀ
4.1. Chemicals
2
: AHF = 0: 150 ml/min). Finally, fluorinated
catalyst 1% Fe(III)/C was prepared.
Hexachlorocyclopentadiene (purity > 99.8%) was obtained from
Jiangsu Anpon Electrochemical Co. Ltd. (Jiangsu, China). AHF
purity > 99.9%), nitrogen gas (purity > 99.9%) and chlorine gas
purity > 99.999%) were purchased from Beijing North Oxygen
Similarly, catalyst 1% Ni(II)/C, 1% Sn(IV)/C, 1% Sn(II)/C, 1% K(I)/C,
1% Ca(II)/C, 1% Cr(III)/C, 1% Zr(IV)/C, 1% Zn(II)/C, 1% Co(II)/C, 1% Cu
(II)/C, 1% Zn–0.2% Fe/C, 1% Zn–0.2% Cu/C, 1% Zn–0.2% Co/C, 1% Fe–
0.2% Cu/C, 1% Fe–0.2% Co/C, 1% Zn–0.2% Fe–0.2% Cu/C, 1% Zn–0.2%
Fe–0.2% Co/C, 1% Zn–0.2% Cu–0.2% Co/C, 1% Fe–0.2% Cu–0.2% Co/C,
1% Zn–0.2% Fe–0.2% Cu–0.2% Co/C, 1% Zn–0.2% Fe–0.2% Cu–0.2% Zr/
C, and 1% Zn–0.2% Fe–0.2% Zr–0.2% Cu–0.2% Co/C were prepared.
(
(
Specialty Gases Institute Co., Ltd. (Beijing, China). Co(NO
ZnCl , NiCl 6H O, Zr(NO 5H O, SnCl 5H O, SnCl , FeCl
CaCl , CuCl 2H O, CrCl O, HNO (conc. purity > 75.0%), 25%
3
)
2
ꢂ
6H
2
O,
2
2
ꢂ
2
3
)
6H
4
ꢂ
2
4
ꢂ
2
2
3
, KCl,
2
2
ꢂ
2
3
ꢂ
2
3
aqueous ammonia and coconut active charcoal were purchased
from Xilong Chemical Co., Ltd., (Guangxi, China).
4.3.3. Catalyst prepared by a coprecipitation method
ZFZCC was typically prepared as following process. Co
4
.2. Instruments
(NO
0 ml aqueous ammonia solution (25 wt%). The solution was then
added dropwise to 300 g solution which contained 30 wt% FeCl
20 wt% Zr(NO and 10 wt% CuCl under continuous stirring. The
3
)
2
ꢂ
2 2
6H O (32.15 g) and ZnCl (41.61 g) were dissolved in
6
Powder X-ray diffraction (XRD) was performed on a Rigaku D/
3
,
MAX 2500 X-ray diffractometer.
3
)
4
2
Specific surface area was measured using nitrogen adsorption
technique on a micromeritics ASAP 2020/Tristar 3000 instrument
pH of the solution was about 8. The slurry of hydroxides was
filtered, washed thoroughly with de-ionized water, dried, ground