Catalyst composition

A catalyst composition having a composition represented by the formula: EQU A.sub.0.1-4 B.sub.0.02-1 Mo.sub.12 Bi.sub.0.5-10 Fe.sub.0.5-10 Na.sub.0-3 P.sub.0-2 O.sub.g wherein A is at least one element selected from the group consisting of cerium, lanthanum, neodium, praseodium, samarium, europium and gadrinium, B is at least one element selected from the group consisting of potassium, rubidium and cesium, and g is the number of oxygen atoms required to satisfy the valence requirements of the other elements present, and supported on silica.

DESCRIPTION 
1. Technical Field 
The present invention relates to a novel catalyst composition exhibiting 
excellent catalytic action on the production of acrolein, methacrolein, 
1,3-butadiene, acrylonitrile or methacrylonitrile by the oxidation or 
ammoxidation of propylene, isobutylene, tert-butanol or 1-butene. 
2. Background Art 
It is known that there have been proposed a number of catalysts to be used 
for the production of acrolein, methacrolein, 1,3-butadiene, acrylonitrile 
or methacrylonitrile by the gaseous phase catalytic oxidation or 
ammoxidation of propylene, isobutylene, tert-butanol or 1-butene. For 
example, U.S. Pat. No. 3,766,092, U.K. Pat. No. 1,319,190 and U.S. Pat. 
No. 4,001,317 disclose multi-component oxide catalyst systems which 
contain molybdenum, bismuth and iron, and other ingredients such as 
cobalt, nickel, etc. as additives. Although subsequent improvements have 
been made on various aspects of catalyst systems of this type, when they 
are employed for the oxidation or ammoxidation of propylene, isobutylene, 
tert-butanol or 1-butene, the yield of the desired product drops within a 
short period of time. This adversely affects the suitability of such 
catalyst for industrial use. 
In Japanese Laid-open Patent Application No. 95513/79 (U.S. Pat. No. 
4,228,098), Japanese Laid-open Patent Application No. 17334/80, Japanese 
Laid-open Patent Application No. 17356/80 and Japanese Laid-open Patent 
Application No. 22639/80, some of the present inventors disclosed a 
catalyst comprising molybdenum, bismuth and iron and a small amount of at 
least one element selected from potassium, rubidium and cesium, which when 
employed for the oxidation or ammoxidation, gave a high yield and kept the 
yield for a long time. 
The present inventors have made further extensive studies on the catalyst 
system and consequently found a catalyst additionally containing an 
element selected from cerium, lanthanum, neodymium, praseodymium, 
samarium, europium and gadolinium, which can be used for the oxidation or 
ammoxidation of propylene, tert-butanol or 1-butene to produce acrolein, 
methacrolein, 1,3-butadiene, acrylonitrile or methacrylonitrile, and gives 
a higher yield for a long time of the reaction. Moreover, it has also been 
found that above all in the ammoxidation, the production rate of 
acrylonitrile or methacrylonitrile can be improved to a great extent. The 
present invention has been accomplished based on these findings. The 
improvement in the production rate reduces the reactor size and the amount 
of the expensive catalyst and results in a great economical effect. 
DISCLOSURE OF THE INVENTION 
Accordingly, the primary object of the present invention is to provide an 
improved novel catalyst composition for producing acrolein, methacrolein, 
1,3-butadiene, acrylonitrile or methacrylonitrile, at a higher yield and 
at a higher production rate by the oxidation or ammoxidation of propylene, 
isobutylene, tert-butanol or 1-butene. 
More particularly the catalyst composition of this invention has a 
composition represented by the formula: 
EQU A.sub.a B.sub.b Mo.sub.12 Bi.sub.c Fe.sub.d Na.sub.e P.sub.f O.sub.g 
wherein 
A is at least one element selected from the group consisting of cerium, 
lanthanum, neodymium, praseodymium, samarium, europium and gadolinium, 
B is at least one element selected from the group consisting of potassium, 
rubidium and cesium, 
a, b, c, d, e, f and g are the atomic ratios of A, B, molybdenum, bismuth, 
iron, sodium, phosphorus and oxygen, respectively, relative to twelve 
atoms of molybdenum, 
wherein: 
a is between 0.1 and 4, 
b is between 0.02 and 1, 
c is between 0.5 and 10, 
d is between 0.5 and 10, 
e is between 0 and 3, 
f is between 0 and 2, and 
g is the number of oxygen atoms required to satisfy the valence 
requirements of the other elements present, 
and supported on silica. 
In the catalyst composition of the present invention, the atomic ratio of 
the component A is a=0.1-4, preferably a=0.3-3. The component B is also 
essential, although minute in its amount, with an atomic ratio selected 
from the range of b=0.02-1, preferably b=0.05-0.5. The presence of sodium 
and phosphorus is not essential, but, when used in amounts within the 
range of the composition cited above, the abrasion resistance of the 
catalyst can be improved. As the carrier for the catalyst composition of 
the present invention, there may suitably be employed silica in an amount 
of 30 to 70% by weight, preferably 40 to 60% by weight, based on the total 
weight of the catalyst composition. 
The catalyst composition of the present invention can be prepared according 
to the known method, for example, by first preparing a slurry of starting 
materials, then spray-drying the slurry and finally calcining the dried 
product. In the preparation of the slurry of the starting materials, as 
the sources for the respective catalyst components, there may suitably be 
employed silica gel for silica, phosphoric acid for phosphorus, ammonium 
salt for molybdenum and nitrates for other components, respectively. For 
this spray-drying of the starting material slurry, a centrifugal system 
may be preferably used. The calcination of the dried product may be 
conducted by carrying out a pre-calcination, if necessary, at 150.degree. 
C. to 500.degree. C., and then at a temperature in the range of from 
600.degree. C. to 750.degree. C., preferably from 650.degree. C. to 
720.degree. C., for 1 to 20 hours. 
Production of acrolein, methacrolein, 1,3-butadiene, acrylonitrile or 
methacrylonitrile with the use of the catalyst composition of the present 
invention may be performed either in a fluidized bed reactor or in a fixed 
bed reactor. The reactant of propylene, isobutylene, tert-butanol, 
1-butene or ammonia is not necessarily required to be of high purity, but 
of industrial grade. As the oxygen source, air is generally used.

EXAMPLES 
A further understanding of the present invention, and the advantages 
thereof, can be had by reference to the following examples. 
(1) Preparation of catalysts 
According to the procedure described below, a catalyst composition was 
prepared having the formula: 
EQU Ce.sub.0.63 K.sub.0.075 Mo.sub.12 Bi.sub.2.42 Fe.sub.6.75 P.sub.0.3 O.sub.g 
supported on 50% by weight of silica. 
To 166.7 g of a silica sol containing 30% by weight of SiO.sub.2 
[Snowtex-N, produced by Nissan Kagaku Co.] was added, with stirring, 0.59 
g of 85% by weight of phosphoric acid, followed by a solution of 36.2 g of 
ammonium heptamolybdate [(NH.sub.4).sub.6 Mo.sub.7 O.sub.24.4H.sub.2 O] 
dissolved in 90 g of water, and finally a mixed solution of 19.84 g of 
bismuth nitrate [Bi(NO.sub.3).sub.3.5H.sub.2 O], 46.61 g of ferric nitrate 
[Fe(NO.sub.3).sub.3.9H.sub.2 O], 4.70 g of cerium nitrate 
[Ce(NO.sub.3).sub.3.6H.sub.2 O] and 0.1 g of potassium nitrate [KNO.sub.3 
] previously dissolved in 33 g of 13.3% by weight nitric acid. The 
starting material slurry thus obtained was transferred into a co-current 
type spray-drier and dried at about 200.degree. C. Spray-drying of the 
slurry was conducted by means of a spraying device equipped with a 
tray-type rotor arranged at the upper central portion of the drier. The 
resultant dried powders were transferred to a tunnel type kiln, 
precalcined at 400.degree. C. for one hour and then calcined at 
690.degree. C. for 2 hours. 
Using the foregoing procedure, the catalysts of the present invention and 
control catalysts were prepared, and their compositions are presented in 
Table 1 and Table 2. As the lanthanum, neodymium, praseodymium, samarium, 
europium, gadolinium, rubidium, cesium and sodium sources in the examples, 
the respective nitrates are employed. The calcination conditions were 
varied suitably as set forth in Table 1 and Table 2. 
(2) Ammoxidation of propylene 
The catalyst (1) as indicated in Table 1 (2 g) was charged into a Vycor 
glass reaction tube having an inner diameter of 8 mm, and a gas mixture of 
6% by volume of propylene (volume ratio of 
propylene:ammonia:oxygen:nitrogen being 1:1.25:1.9:12.5) was passed 
through the tube at a flow rate of 2.1 liter/hour (calculated at NTP) at a 
temperature of 460.degree. C. at atmospheric pressure. The result of this 
reaction was evaluated by the two indices of the acrylonitrile yield and 
the production rate of acrylonitrile as defined by the following formulas, 
and their values are shown in Table 1. 
##EQU1## 
The same reaction as above was repeated using each of the other catalysts 
listed in Table 1, and the results are also listed in Table 1. But, the 
flow rates of the gas mixtures were suitably varied as shown in Table 1. 
(3) Ammoxidation of Isobutylene (or Tert-Butanol) 
The catalyst (16) as indicated in Table 2 (1 g) was charged into a Vycor 
glass reaction tube having an inner diameter of 8 mm, and a gas mixture of 
6% by volume of isobutylene (volume ratio of 
isobutylene:ammonia:oxygen:nitrogen being 1:1.5:2.5:11.7) was passed 
through the tube at a flow rate of 2.4 liter/hour (calculated at NTP) at a 
temperature of 460.degree. C. at atmospheric pressure. The result of this 
reaction was evaluated by the two indices of the methacrylonitrile yield 
and the production rate of methacrylonitrile as defined by the following 
formulas, and their values are shown in Table 2. 
##EQU2## 
The same reaction as described above was repeated using each of the other 
catalysts listed in Table 2, and the results are also listed in the same 
Table 2. But, the flow rates of the gas mixtures were suitably varied as 
shown in Table 2. For the catalyst (16) and the control catalyst (22), the 
same ammoxidation as described above was repeated using tert-butanol in 
place of isobutylene to obtain the results as indicated in Table 2. 
(4) Oxidation of Propylene 
The catalyst (1) as indicated in Table 1 (1.5 g) was charged into a Vycor 
glass reaction tube having an inner diameter of 8 mm, and a gas mixture of 
6% by volume of propylene (volume ratio of propylene:oxygen:steam:nitrogen 
being 1:1.9:3:10.8) was passed through the tube at a flow rate of 2.3 
liter/hour (calculated at NTP) at a temperature of 380.degree. C. at 
atmospheric pressure. 
##EQU3## 
was found to be 85.8%. 
(5) Oxidation of Isobutylene 
The catalyst (16) as indicated in Table 2 (1 g) was charged into a Vycor 
glass reaction tube of 8 mm inner diameter, and a gas mixture of 3% by 
volume of isobutylene (volume ratio of isobutylene:oxygen:steam:nitrogen 
being 1:2:3:27.3) was passed through the tube at a flow rate of 2.4 
liter/hour (calculated at NTP) at a temperature of 400.degree. C. at 
atmospheric pressure. 
##EQU4## 
was found to be 82.6%. 
(6) Oxidation of 1-Butene 
The catalyst (1) as indicated in Table 1 (1 g) was charged into a Vycor 
glass reaction tube having an inner diameter of 8 mm, and a gas mixture of 
6% by volume of 1-butene (volume ratio of 1-butene:oxygen:steam:nitrogen 
being 1:1.8:3:10.9) was passed through the tube at a flow rate of 2.6 
liter/hour (calculated at NTP) at a temperature of 370.degree. C. at 
atmospheric pressure. 
##EQU5## 
was found to be 89.0%. 
TABLE 1 
__________________________________________________________________________ 
Catalyst Composition and Results of Ammoxidation of Propylene 
Ammoxidation 
Catalyst Composition Flow Rate Production 
Cat. SiO.sub.2 
Calcination 
(l/Hr Yield 
rate 
No. A B Mo Bi Fe Na P (wt %) 
condition 
at NTP) 
(%) R(Hr.sup.-1) 
__________________________________________________________________________ 
1 Ce.sub.0.63 
K.sub.0.075 
12 2.42 
6.75 
0 0.3 
50 690.degree. C., 6 
2.1 87.5 
0.130 
2 La.sub.0.63 
" " " " " " " 700.degree. C., 4 
2.3 87.1 
0.142 
3 Nd.sub.0.63 
" " " " " " " 690.degree. C., 2 
1.9 86.2 
0.116 
4 Pr.sub.0.63 
" " " " " " " " " 86.8 
0.117 
5 Sm.sub.0.63 
" " " " " " " " 1.8 85.9 
0.110 
Catalyst 
6 Eu.sub. 0.63 
" " " " " " " " 2.0 86.3 
0.123 
of the 
7 Gd.sub.0.63 
" " " " " " " " " 86.0 
0.122 
present 
8 Ce.sub.0.4 La.sub.0.23 
" " " " " " " 700.degree. C., 6 
2.3 87.2 
0.142 
invention 
9 Ce.sub.0.63 
Rh.sub.0.06 
" " " " " " 690.degree. C., 4 
2.0 87.1 
0.124 
10 Ce.sub.0.63 
K.sub.0.03 Cs.sub.0.02 
" " " " " " " " 86.8 
0.123 
11 Ce.sub.1.33 
K.sub.0.075 
" 3.67 
5.00 
" 0 " 690.degree. C., 2 
1.9 86.7 
0.117 
12 Ce.sub.2.10 
" " " " " 1 " 710.degree. C., 2 
1.8 85.8 
0.109 
13 Ce.sub.0.80 
" " 2.80 
4.40 
1.2 
0 " 700.degree. C., 2 
1.9 86.2 
0.116 
Control 
14 -- " " 2.42 
6.75 
0 0.3 
" 690.degree. C., 2 
1.3 85.2 
0.078 
catalyst 
15 -- " " 4.07 
7.15 
" 1 " " 1.2 85.4 
0.073 
__________________________________________________________________________ 
TABLE 2 
__________________________________________________________________________ 
Catalyst Composition and Results of Ammoxidation of Isobutylene (or 
Tert-Butanol) 
Ammoxidation 
Catalyst Composition Flow Rate Production 
Cat. SiO.sub.2 
Calcination 
(l/Hr Yield 
rate 
No. A B Mo Bi Fe Na P (wt %) 
condition 
at NTP) 
(%) R(Hr.sup.-1) 
__________________________________________________________________________ 
Catalyst 
16 Ce.sub.1.40 
K.sub.0.3 
12 2.77 
4.47 
0 1.2 
50 690.degree. C., 4 
2.4 82.1 
0.354 
of the 2.4* 82.3 
0.355 
present 
17 La.sub. 1.0 Sm.sub.0.4 
" " " " " " " 700.degree. C., 2 
2.3 81.7 
0.377 
invention 
18 Eu.sub.0.5 Pr.sub.0.9 
" " " " " " " 690.degree. C., 2 
2.2 80.5 
0.318 
19 Ce.sub.0.8 Gd.sub.0.8 
" " " " 1.0 
" " 700.degree. C., 2 
"r 81.6 
0.322 
20 Ce.sub.1.40 
K.sub.0.2 Rb.sub.0.05 
" " " 0 " " 690.degree. C., 2 
2.4 81.3 
0.350 
21 " Cs.sub.0.2 
" " " " " " " 2.3 81.0 
0.334 
Control 
22 -- K.sub.0.3 
" " " " " " " 1.2 79.3 
0.171 
catalyst 1.2** 79.2 
0.171 
23 -- K.sub.0.072 
" 5.4 
7.8 
" " " " 1.4 77.8 
0.196 
__________________________________________________________________________ 
[Remark] 
(*) and (**) are results of ammoxidation of tertbutanol, and others are 
those of isobutylene. 
The foregoing examples illustrate, without limitation, the catalyst and 
process of the present invention. It is understood that changes and 
variations can be in the examples without departing from the spirit and 
scope of the invention as defined in the following claims.