Applied Catalysis, 30 (1987) 141-149 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands
ENANTIOSELECTIVITY
Yuriko
NITTA,
Department
OF TARTARIC
Masayuki
KAWABE
of Chemical
Toyonaka,
Osaka
(Received
1 July
ACID-MODIFIED
Ni-A1203
and Toshinobu
CATALYSTS
IMANAKA
Faculty
Engineering,
141
of Engineering
Science,
Osaka University,
560, Japan.
accepted
1986,
6 November
1986)
ABSTRACT Effects of the preparation conditions on the properties of precipitated Ni-Al203 (1:l) catalysts precursors were studied using thermogravimetric analysis (TGA). The larger part of the nickel species on alumina, having no interaction with the support, is readily reduced and yields large nickel crystallites, while the remaining smaller part of the nickel species, having strong interactions with the support, has a lower reducibility and yields smaller crystallites. The reducibility of only the latter species is affected by the preparation conditions. The resulting bimodai size distribution of nickel crystallites on alumina explains the low activitv and enantioselectivitv of modified Ni-A1702 catalvsts oreoared with sodium carbonate. A small amount of Fe salt precipitatedLo; the support prior to the precipitation of the Ni salt increases the enantioselectivity of the catalyst, probably as a result of blocking the sites having strong metal-support interactions.
INTRODUCTION The asymmetric attracted
hydrogenation
3-hydroxybutyrate reactions
structure
[6-81, we reported
on the mean
catalysts
catalysts
prepared
active
use.
methyl
to the understanding
of the catalyst
the reaction
of the
surface
is
is known to be highly
which
because
selective
of precipitation
0166-9834/87/$03.50
size of nickel
size distribution
affect
of changes Ni-Si02
(CSD) of nickel
method
the composition
leads to variable
and reduction.
0 1987 Elsevier Science Publishers B.V.
sodium
carbonate,
and the reducibility
activity
were
plays an
of the catalyst.
with
and selectivity
in the CSD of nickel
catalysts
of modified
and that, with supported
of the enantioselectivity
by a precipitation
variables
precursors,
and satisfactorily conditions
synthesis
for the enantio-
that the enantioselectivity
crystallite
the crystallite
all preparation
the catalyst H2-reduced
has been devoted
although
role in the determination
With Ni-SiO2 almost
for asymmetric
(MAA) to optically
[2-51. The morphology
has long
but also for industrial
Raney Ni catalysts
acetoacetate
of much debate,
papers
depends
catalysts,
important
catalysts
using enzymes
sensitive.
In previous catalysts
modified
of methyl
catalysts
without
not only scientifically
(MHB), much effort
on metal
still the subject
products
on heterogeneous
importance,
Izumi et al. [I] developed
selective
nickel
of natural
Studies
attention.
are of particular Since
synthesis
prepared
[9,10].
Highly
under optimal
of
of the active
1
0 0 75 90 90
NOH-1
NOH-2
NOH-3
NOH-4
NOH-5
to NCO-5 are samples
50
90
NCO-5
aNCO-l
20
90
NCO-4
48
24
24
24
72
with Na2C03
20.8
22.2
20.9
28.3
5
5
9
16
31
24
24
24
31
31
nm
Dc/
Ni-A1203
164
160
142
108
97
106
113
101
104
105
m2g-'
5a/
catalysts
SM/
6
5
6
12
11
IO
7
8
IO
14
nm
Ds/
with NaOH.
37.2
41.3
34.0
17.5
19.0
21.6
31.8
26.6
21.2
15.9
m2g-'
and NOH-1 to NOH-5 precipitated
3.27
2.09
1.60
1.11
23.7
0.62
0.49
15.8 28.6
0.86
48
24
18.3
0.98
precipitated
120
120
110
120
120
la.7
0.37
24
"/ 0
OY/
24
-1
13.2
50
NCO-3 110
0 75
NCO-2
r0'
0.37
72
20
time/h
0
temp./Y
temp./"C
Drying
NCO-1
Drying
Precipitation
of modified
mm01 g-'min
on the properties
conditions
conditions
Preparation
of preparation
Precursora
Effects
TABLE
144 Hydrogenation A 10 ml volume the modified
a glass autoclave activity
determined
MAA was hydrogenated
at 60°C under a starting
equipped
with a magnetic
(ro) of the catalyst
the initial
measure
of distilled
catalyst
from the optical
stirring
was determined
15 min of the reaction.
system.
yield
of the distilled
(IO ml) with -2 by using
of IO kg cm
The hydrogenation
from the pressure
The optical
rotation
of the enantioselectivity
in ethyl acetate
H2 pressure
decrease
during
(OY) of the product,
MHB,
product
as a
was employed
of the catalyst.
Analysis The thermogravimetric thermal
analyser.
experiments
A portion
were carried
out using a Shimadzu
(ca. 40 mg) of a freshly
prepared
precursors
heated
in a flow of N2 or H2 to 600°C at lO"C/min
unless
degree
of reduction
from the weight
measurement catalyst
broadening
surface
area
crystallite
from the half-width
in the XRD pattern
of instrumental and metal
was estimated
in a flow of H2. The mean
was calculated
nickel metal
-196°C
of the catalyst
by Warren's
and by H2 adsorption
stated
method
after correction
FIGURE
correspond
to the precursors
at
nl
3;o
100
500
500
Temperature/"C
1 DTG profiles measured precursors
(Sit)
I
300
Ni-Al203
area
by N2 adsorption
at 25"C, respectively.
Temperature/"C
various
in the
for the effects
[17]. The BET surface were measured
I
100
The
loss in a TG
sire (DC) of nickel
b)
I
was
otherwise.
of the peak on the (111) plane of
of the catalyst
(SM) of the catalysts
DT-30
in (a) a flow of N2 and (b) a flow of H2 for
prepared listed
by using Na2C03 in Table
1.
(--)
and NaOH (---). Numbers
145 RESULTS
AND DISCUSSION
Table
1 lists the catalytic
from various conditions
precursors.
did not affect
of nickel
catalysts
in the resulting
widely,
selectivity
depending
of the weight
carbonate
appear
reported
CatalyStS
the hydrogenation
(DTG) curves,
although
activity,
i.e., the first derivatives
for the various
Ni-Al203
of adsorbed at around
water
and the water
IOO-150°C
and ZOO"C,
precursors
to the weight
respectively.
These
each other when they are large. With
the precursors
using Na2C03,
the peak around
to the decarboxylation
temperature
much
shifted
[IO]. However,
of Ni-Al203
in the basic
nickel
losses
that A1203
carbonate
prepared
does not accelerate
nickel
two peaks around
hydroxide
interaction position
having
conditions,
The DTG profiles of the preparation A1203
ture, whereas
species,
be detected
the larger the support
of nickel
hydroxycarbonate,
catalysts
aluminate
C19,2D]
intensity with
Ni(OH)2
clearly
but also
that,
regardless
carbonate
has some
with the support, rate, which
[18]. The formation
and the decom-
at relatively
Ni(OH)2,
of
strong
the preparation
on
low tempera(mild or
(Figure
than Si02 with metal
was reported
NaOH
and A1203.
and has a low reducibility
of the very low reduction
to the formation
by using
to the decomposition
and is reduced
interaction
it seems
in the precursor
part of the basic nickel
interaction
very strong
nickel
coprecioitated
between
was
from the
Therefore,
prepared
slightly
part of the Ni species,
has a greater
by DTG because
aluminium
interaction
com-
than 50% even
and a relatively
The relative
peak increased
with the support
having
interaction
in a flow of H2 showed more
with
the remaining
interaction
is known that A1203 nickel
measured
corresponding
respectively.
increasing
conditions,
has no interaction
strong)
280 and 4OO"C,
of the latter
indicating
to Ni(OH),
in
of NiC03
were estimated
of NiC03
of the precursors
of NiC03
conditions
to be larger (NCO-5).
the change
increasing
percentages
conditions
no or only a weak
with the support,
temperature
precursors found
by of
in the chemical
The molar
and were
severe
with
in the preparation
in the Ni-A1203
under
prepared
in the percentage
of the variation
precursors.
as much as SiOp does. The DTG profiles exhibited
a decrease
with a change
in the range ZOO-500°C
for the precursors
to a lower temperature
the extent
precursors
less than that for the Ni-Si02
weight
corresponding
indicating
of preparation,
the precursor position
carbonate,
320°C,
in
of crystallization
peaks overlap
free basic nickel
the
the enantio-
la. The peaks corresponding
in Figure
losses due to the desorption
obtained
the preparation
constant.
were measured
loss curves,
catalysts
and the mean Cr'YStallite size
as with Ni-Si02
and hence
catalysts,
thermogravimetric
a flow of N2 and are shown
of nickel
as much
on the .preparation conditions,
was low and almost
The differential
Ni-Al203
hand, when NaOH was used as the precipitant
[IO]. On the other
DC of nickel varied
of modified
used as the precipitant,
the enantioselectivity
in the Ni-Al203
previously
properties
When Na2C03was
lb). It
species.
however,
The
may not
is probably
of the Feitknecht
not only in the preparation
in the deposition-precipitation
due
compound, of method
146 using Y-Al203
activated
of this compound preparation patterns
conditions,
although
and the degrees
examined. latter
at a high pH [Zl]. In our case also,
could occur at the alumina
The strength
smaller
surface,
no corresponding
of reduction
were
of the interaction
part of the nickel
the limited
especially
under
peaks were detected
nearly
on the XRD
100% for all the catalysts
and hence the reducibility
species
formation
severe
seem to be affected
of only the
by the preparation
conditions. Hence,
the reduction
of nickel, as already lites
of these Ni-A1203
shown
(which are more selective
nickel
carbonate
and smaller
come from nickel
species
nickel-aluminium
compounds.
the Ni-A1203 difference
catalysts
between
(Table NCO-5
compound,
H2 reduction.
The finding
enantioselectivity conditions
catalysts
originate
For the precursors
prepared
with NaOH,
and hence with high reducibility,
ditions
became
support
interaction,
small nickel
The reduction
of the Ni-A1203 and NOH-5
in Table
agreement
with each other.
The proportion estimated
1).
prepared
groups
and found
C18,22,24,25].
lites from the nickel the enantioselectivity was added tation
when
interaction our reaction
reducibility,
by using NaOH under
a
support
crystal-
inter-
the preparation species will
con-
with a stronger
result
in only
and the low selectivity
severe
species
having
a strong
conditions
having
a strong
of the Ni-A1203 on A1203
with Na2C03.
severe
with
(NOH-4
and,
to metal.
interaction
precursors
of small interaction
a small amount conditions
prior
in addition,
As shown
was
with various
the results
The Fe salt was expected
to the Ni salt with the support when reduced
support
catalysts,
under
support
of Ni-A1203
in agreement
In order to prevent the formation
species
conditions
Ni(OH)2
the high activity
to be lo-20%,
species
and precipitated
of nickel
nickel
low reducibility.
disappeared
on the basis of the TG measurements
loadings,
of smaller
mild
In these cases, the values of DC and Ds are in fair
of the nickel
nickel
after
as high an
relatively
without
of remaining
This explains
catalysts
with
of the non-reducible
can exhibit under
having
in these catalysts
crystallites
the species
and hence with a lower
crystallites.
reduced
species
action,
severe.
nickel
in terms of the absence
from the nickel
line broadening
from the precursor
formation
catalysts
when
of
The significant
from X-ray
obtained
of smaller
that the Ni-A1203
as Ni-Si02
possible
(D,) for the catalysts
to the partial
basic
and selectivity
as the precipitant.
areas
CSD
crystal-
but less selective)
of small crystallites
the proportion
[7] is also explained
lites which
surface
nickel
including
the low activity
size obtained
the presence
in a bimodal
larger
(more active
high OY for the catalyst
diminishes
result
interaction,
by using Na2C03
1 could be attributed
which
support
crystallite
from metal
supports
will
come from non-interacting
crystallites
This explains
prepared
1). The relatively in Table
nickel
the nickel
DC strongly
but less active)
with a strong
(DC) and that estimated larger
precursors
by TPR [ZZ] and EM [23] studies;
nickel
of other crystal-
and to increase of an Fe salt to the precipi-
to have a similar to be inactive
in Figure
under
2, the addition
147
I
Fe/(Fe+Ni) FIGURE
2
Dependence
Ni-Fe-A1203;
FIGURE
3
Heating
TABLE
of optical Ni-Fe-Si02.
DTG-in-H2
profiles
Fe contents,
rate:
Temperature/"C
yields
on the Fe content
of Ni-Fe-A1203
Fe/(Fe+Ni):
precursors
(a) 0 wt%;
in the catalysts.
prepared
(b) 7 wt%;
(c) 14 wt%;
(d) 21 wt%.
S"C/min.
of support
on the properties
of supported
Ni catalysts.
OY/%
DJnm
SiO
49.7
8
2 Si02-A1203
3
Si02-A1203
4
A1203
(SAL)a
28.9
9
(SAH)~
23.9
14
18.3
24
aAl
content
13.8%.
bA1203
content
28.6%.
of about
IO wt% of Fe to Ni was found
enantioselectivity crystallites action.
(0)
under severe
Support
2
500
2
Effects
1
1
I
300
100
(wt%)
(0)
conditions.
40
30
20
10
f
1
I
I
of Ni-A1203
originating
The Ni-Fe-A1203
selectivity
to be most effective.
catalysts
from the nickel (9:l:lO)
catalyst
but also as high an activity
by the significant in the species
decrease
having
of added Fe, as shown
in the amount
a mild support in Figure
is attributable species
Accordingly,
the low
to the small nickel
having a strong
support
inter-
had not only as high an enantioas Ni-Si02
catalysts.
of free nickel
interaction
3. On the other
with
This can be explained
species
and the increase
an increase
hand, the addition
in the amount of Fe to the
148
FIGURE
4
listed
in Table
Ni-SiD2
DTG-in-H2
500
of the precursors -1 .
prepared
catalyst
had negative
effects
just as with
the addition
Silica-alumina
with different
of the support
in the enantioselective
the Ni-silica-alumina
catalysts
catalysts.
The acidity
enantioselectivity explained supports
which
between
effect
least partly,
explanation
out previously
catalysts
in Table
intermediate
appears
Ni-y-A1203
it may affect
of crystallite
and the support.
will be required.
[7,8], the difference catalysts
of nickel species
on different
in the precursors,
from the catalyst
accompanying
studies
concerning
in
can be
metal
surface
[14] can also be ascribed,
in the DC of nickel [6]. Further
influence
studies
and Ni-Si02
of
and
the CSD of
the metal
with nickel
catalysts
those of Ni-Si02
between
papers
of aluminium
4, the
behaviour
to have no direct
in the morphology
interactions
to examine Ni catalysts
2 and Figure
between
although
in our previous
[261.
of supported
sizes and the reduction
the interaction
Raney-Ni
to an increase
nickel
As shown
catalyst,
of the removal
of the effects
supports
and the selectivity elsewhere
was used as a support
the properties
of a support
modified
of modified
pointed
contents
of this point further
suggested
have different
the selectivity
modified
were
in terms of the difference
The favourable
already
by affecting
discussion
Thus, as already
of Pd reported
crystallite
of the resulting
Ni in the catalyst For a detailed
A1203
hydrogenation. the mean
on the properties
on both the activity
influences
enantioselectivities,
Ni-A1203
by using different
rate: 5°C min
of the catalyst,
if the acidity
I
300 Temperature/"C
profiles
2. Heating
I
I
I
I
100
on
at
the procedure,
as
the detailed
size on the enantioselectivity
of
are in progress.
REFERENCES 1 2 3 4
Y. Izumi, M. Imaida, H. Fukawa and S. Akabori, Bull. Chem. Sot. Jpn., 36 (1963) 21. Y. Izumi, Adv. Catal., 32 (1983) 215. E.I. Klabunovskii and A.A. Vedenyapin, Asymmetricheskii Katakiz; Gidrogenizatsiya na Metallakh, Nauka (Moscow), 1980. M. Bartok, Stereochemistry of Heterogeneous Metal Catalysis, John Wiley & Sons New York. 1985. 0.511.
149 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
W.M.H. Sachtler, Catalysis of Organic Reactions, Marcel Dekker (New York), 1985, p.189. Y. Nitta, F. Sekine, T. Imanaka and S. Teranishi, Bull. Chem. Sot. Jpn., 54 (1981) 980. Y. Nitta, F. Sekine, T. Imanaka and S. Teranishi, J. Catal., 74 (1982) 382. Y. Nitta, 0. Yamanashi, F. Sekine, T. Imanaka and S. Teranishi, J. Catal., 79 (1983) 475. Y. Nitta, T. Utsumi, T. Imanaka and S. Teranishi, Chem. Lett., (1984) 1339. Y. Nitta; T. Imanaka and S. Teranishi, J. Catal., 96 (1985) 429. E.I. Klabunovskii. A.A. Vedenvaoin. N.D. Zubareva. N.P. Sokolova and Yu. M. Talanov, React. Kinet. Catal.-L&t:, 2 (1975) 291; A. Hoak and W.M.H. Sachtler, J. Catal., 58 (1979) 276. T. Harada, S. Onaka, A. Tai and Y. Izumi, Chem. Lett., (1977) 1131. T. Harada, M. Yamamoto, S. Onaka, M. Imaida, H. Ozaki, A. Tai and Y. Izumi, Bull. Chem. Sot. Jpn., 54 (1981) 2323. Yu. M. Talanov and N.P. Sokolova, Kin. A.A. Vedenyapin, E.I. Klabunovskii, Katal., 16 (1975) 436. Y. Izumi, S. Tatsumi and M. Imaida, Bull. Chem. Sot. Jpn., 42 (1969) 2373. B.E. Warren, J. Appl. Phys., 12 (1941) B75. S. Narayanan and K. Uma, J. Chem. Sot., Faraday Trans. I, 81 (1985) 2733. D.C. Puxley, I.J. Kitchener, C. Komodromos and N.D. Parkyns, "Preparation of Catalysts III”, Elsevier, 1983, p.237. E.C. Kruissink, L.L. van Reijen and J.R.H. Ross, J. Chem. Sot., Faraday Trans. I, 77 (1981) 649. H. Schraper, D.J. Amesz, E.B.M. Doesburq, P.H.M. de Korte, J.M.C. Duartel and L.L. van.Reijen, Applied Catal., 16 (1985) 417. J. Zielinski. J. Catal.. 76 (1982) 157. M. Yamada, Shokubai, 26-(1984) 286. M. Wu and D.M. Hercules, J. Phys. Chem., 83 (1979) 2003. A. Sannomiya, M. Yano and Y. Harano, Kagaku Kogaku Ronbunshu, 11 (1985) 381. Y. Nitta, T. Utsumi, T. Imanaka and S. Teranishi, J. Catal., 101 (1986) 376.