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Патент USA US2402683

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Patented June 25, 1946
.
‘2,402,683
UNITED STATES PATENT. OFFICE
2,402,683
HYDROGENATION CATALYSTS AND
METHODS OF PREPARATION
Frank Kerr Signalgo, Wilmington, Del., assignor '
. to E. I. du Pont de Nemours 8; Company, Wil
mington, Del., a corporation of Delaware
' No Drawing. Application February 16, 1940,
Serial No. 319,241
11 Claims. (Cl. 252-221;.4)
1
This invention relates to metal'sul?de catalysts
‘ for use in hydrogenation reactions and to meth
ods of preparing such catalysts.
.
The literature on the use of metal sul?de, cat
alysts for the destructive hydrogenation of car
bonaceous materials is very extensive. Such
' metal sul?des are prepared by a. variety of meth
2
ity of the resulting catalyst is adversely affected.
Generally, the ‘sul?dation is carried out at tem
peratures below 150° C. and preferably below
100° C. When the sul?ding agent is sulfur, this
is conveniently dissolved in‘ a suitable solvent
which is stirred with the ?nely divided active
metal until no further reaction occurs, and when
it is hydrogen sul?de, this is passed thru a sus
pension of the ?nely divided metal in' a solvent
ods such as precipitation, decomposition of thio
salts, and heating metals or metal compounds
with volatile sulfur-containing materials such as 10 for hydrogen sul?de.
‘sulfur, hydrogen sul?de, carbon bisul?de, mer
Example I
captans,'etc. The formation of these sul?des has
An active hydrogenation catalyst was prepared
been accomplished by heating the metals in the
as follows. Anhydrous cobalt chloride was sus
presence of the sulfur containing materials to
relativelyhigh temperatures such as those be 15 pended in dimethyl glycol ether containing dis
solved naphthalene. Two gram atoms of sodium
tween 150° to 700° C. The standard inorganic
for each mole of cobalt chloride were added in
reference‘ books state in effect that iron, cobalt,
portions during two hours, the temperature of the '
nickel, molybdenum; etc., do not react with hy
solution being maintained in the range from
drogen sul?de or sulfur at lower temperatures.
The metal sul?de catalysts described in the 20 0-25° C. The green solution of sodium naph
thalene that formed immediately reacted with
literature are active for the destructive hydro
the cobalt chloride to precipitate ?nely divided
genation of carbonaceous materials and for the .
cobalt metal and sodium chloride. The insoluble
desulfurization of petroleum and gases at high
cobalt metal and sodium chloride were ?ltered
temperature, as for example 300° to 600° C.
These drastic conditions of temperature are not 25 from the solvent and washed with fresh solvent
to remove the naphthalene and thereafter washed
suitable for carrying out certain‘ desirable hy
with water to remove the sodium chloride. The
drogen reductions of organic compounds, since
resultingv ?nely divided black cobalt powder was
extensive cracking and hydrogenolysis results
very pyrophoric and must be protected from‘
and mixtures of hydrocarbons are obtained. It
is therefore essential to the successful hydrogen 30 oxidation by keeping it in an inert atmosphere
or under a suitable liquid medium such as alcohol.
reduction of many organic sulfur compounds
The pyrophoric cobalt was now suspended with
that‘ the catalysts employed be active at low
stirring in alcohol and a stream of hydrogen
temperatures so that simple addition of hydrogen
sulfide gas was bubbled through the solution
or cleavage by hydrogen will occur without ac
companying disruptive side reactions. The cat 35 which was cooled to maintain the temperature
below 50° C. The hydrogen sul?de reacted rap
alyst must of course be immune to sulfur poison
idly with the cobalt metal with the liberation of
in if sulfur or sulfur compounds are involved.
This invention has as an object the prepara
hydrogen.
When no more hydrogen was evolved
the cobalt sul?de
tion of certain new and useful sulfactive cat
alysts. A further object is to prepare certain 40
CO*+H1S ———v CoS+Hz (see footnote)
new and useful catalysts for effecting hydrogena
(In this and in subsequent equations the asterisk denotes the metal
tion reactions. A still further object is the prepa
in an activated or pyrophoric condition and not in the ordinary
form which does not undergo the reaction indicated under the
ration of hydrogenation catalysts that are active
conditions described herein.)
under mild conditions of temperature. Another
formed was ?ltered from the alcohol and washed
object is to develop certain new processes for the
with fresh alcohol to remove hydrogen sul?de.
production of such catalysts. Other objects will
The ?nal product was still pyrophoric and had
be apparent from the reading of the following de
to be protected from atmospheric oxidation. The
scription of the invention.
_
weight ratio of cobalt to sulfur in the product
These objects are accomplished by the follow
ing invention which comprises treating a ?nely 50 was found to be 2.7. This corresponds approxi
mately to the conversion of 70% of the cobalt
divided metal in activated or pyrophoric form
to cobalt monosul?de. This product was very
with a sul?ding agent under conditions such
active for carrying out catalytic hydrogenation
that the heat of reaction is removed at such a
rate that the temperature of the reactants is
reactions as shown by the following experiment.
prevented from rising to a point where the activ
A solution of 75 parts of sodium para-toluene
2,402,688
'
4
3
sul?nate in 150 parts of water was charged to
gether with 15 parts of the sul?ded cobalt cata
lyst described above, into a pressure autoclave
and hydrogen charged into the autoclave to a
pressure of 2300 lbs/sq. in. The autoclave was
heated at 200° C. with suitable agitation for 3%
hrs. After cooling the autoclave, the contents
were ?ltered from the catalyst. Acidi?cation of
the aqueous solution precipitated solid para
thiocresol in an amount corresponding to 50 %- of 10
the theoretically possible yield. Some toluene
and hydrogen sul?de was also formed.
ing ‘the autoclave and removing ‘the catalyst,
crude thionaphthol was obtained as before. The
catalyst consisted of nickel sul?de-on-kieselguhr,
the metallic nickel and the sulfur having reacted
to form the active catalyst during the period of
heating up the autoclave. These transformations
may be formulated as follows:
ms
R-s-siH-H, --. men
Example IV
An active molybdenum sul?de catalyst was pre- ‘
catalyst
pared by the following procedure.
Thirty-six
15 parts of a ?nely ground alloy of equal weights of
Example II
molybdenum and aluminum was suspended in 300
Another type of‘ sulfactive catalyst was pre
parts of boiling water and a solution of 130 parts
pared as follows, Pyrophoric nickel-on-kiesel
of concentrated sulfuric acid in 100 parts of water
guhr was prepared by reducing precipitated
was added slowly during one hour. After all of
nickel carbonate-on-kieselguhr with hydrogen at 20 the acid had been added the mixture was di
a temperature of 425°-475° 'C. The cooled re
gested further for 4 hours. The ?nely divided
duced pyrophoric material was then transferred
insoluble product was then ?ltered and washed
without exposure to air to a saturated solution
' free from acid and soluble salts.
of sulfur in benzene. The catalyst was then
stirred with the solution for several minutes at 25
room temperature and then allowed to settle.
The supernatant liquid was decanted and the‘
nickel stirred with a second portion of benzene
saturated with sulfur.. After no more sulfur
was taken up by the nickel-on-kieselguhr the
product was ?ltered and washed with benzene to
remove excess sulfur. Analysis showed that the
catalyst had the composition, NiSo.95+kiese1guhr
and that practically complete conversion of nickel
to nickel sul?de had occurred.
-
drogenation catalyst as shown by the following
experiment.
35
Fifteen parts of the sul?ded molybdenum
catalyst
The activity of the sul?ded nickel so prepared was
The molybde
num thus obtained was extremely pyrophoric and
must be protected from the air. It was then
transferred to methanol, and hydrogen sul?de
gas was bubbled through the methanol suspen
sion of the product for 8 hours at room tempera
ture. The catalyst was ?ltered from the meth
anol solution and dried. Analysis showed the
weight ratio of molybdenum to sulfur to be ap
proximately 6:1. This product was an active hy
prepared
as
described
above
was
charged, together with 100 .parts of pentade
shown by the following experiment.
A benzene solution of 100 parts of crude alpha;
canons-8 and 33 parts of sulfur, into a high
pressure autoclave. Hydrogen was admitted to
naphthyl disul?de was charged into an autoclave 40 a pressure of 3000 lbs/sq. in. and the autoclave
heated to 120° C. After one-half hour the pres
together with 10 parts of the sul?ded nickel-on
sure had decreased 1100 lbs/sq. in. Thereafer
kieselguhr catalyst and the autoclave was
the temperature of the autoclave was raised to
charged with hydrogen to a pressure of 500 lbs./
200° C. and after 5 hours no further absorption
sq. in. On heating the autoclave to 150° C. the
absorption of hydrogen commenced as evidenced 45 of hydrogen occurred. On cooling the autoclave,
and removal of the catalyst, there was obtained
by a decrease in the pressure. Additional hydro
on distillation pentadecanethiol-8 in 76% yield.
gen was added when the pressure had dropped to
This type of reaction is represented by the fol
200 lbs/sq. in. to replace that absorbed. After
lowing equations.
31/; hours the total pressure drop was 600 lbs./sq.
in. and no further reaction occurred. After ?l 50
tering the catalyst from the solution and removal
of the solvent by distillation, there was obtained
a mixture of crude thionaphthols from which
pure thio-alpha-naphthol was obtained by dis
55
tillation.
catalyst
By way of contrast the above experiment was
—‘ zR-SH
carried out under identical conditions except
Example III
that 15 parts of a molybdenum trisul?de cata
The sul?ding treatment of ?nely divided active 60 lyst prepared by heating ammonium thiomolyb
R-—S-S~R + H,
metals to obtain sulfactive catalysts may be car
ried out in the same equipment in which the cata
lyst is used. for hydrogenation reactions as shown
date was substituted for the sul?ded molybdenum
catalyst described above. After the reaction had
ceased, the product was worked up as before and
.pentadecanethiol-8 was obtained in only 16%
Ten parts of freshly reduced pyrophoric nickel 65 yield from the pentadecanone-B.
on-kieselguhr in ?nely divided form was charged
Example V
together with 5 parts of sulfur and 96 parts of
Pyrophoric ?nely divided molybdenum was
crude naphthyl disul?des into an autoclave as in
the preceding example. The autoclave was
prepared by treating an alloy of aluminum and
charged with hydrogen to a pressure of 500 lbs./ 70 molybdenum with sulfuric acid as described above
sq. in. and heated to 100° C. during 1/2 hour to
under Example IV. The product so obtained was
allow the metal to be converted to the metal sul
treated at room temperature with several por
?de. The temperature was then raised to 150° C.
tions of benzene saturated with sulfur until no
Rapid absorption of hydrogen ensued and after 3
more sulfur was taken up by’ the molybdenum.
hours no further reaction occurred. After cool
The sul?ded molybdenum so obtained was an
below.
'
>
2,402,883
5
6
active‘hydrogenation catalyst, as shown by the
lbs/sq. in. and the autoclave heated ‘to 100“ C.
during 1/.» hour to convert the iron to the active
sul?de catalyst. The temperature was then
following results.
.
y
A solution of 50 parts of sodium sul?te in 200
parts of water was charged into an autoclave
together with 10 parts of the sul?ded molyb
denum catalyst described above. Hydrogen was
admitted to the autoclave to a pressure of 1500
lbs/sq. in. and the autoclave heated to 125° C.
'After 21/2 hrs. the pressure had dropped 500
lbs./sq.. in. and the reaction was complete. On
working up the reaction product sodium thio
sulfate was obtained in practically quantitative
yield.
catalyst
--——>
NMSgOH-ZNBOH-{cHzO
raised to 150° C.
A rapid reaction ensued, as
evidenced by the decrease in hydrogen pressure,
and it was necessary to add hydrogen from time
to time to maintain the total pressure in the range
from 1000 to 2000 lbs/sq. in. The total pressure
drop amounted to 1800'lbs./sq. in. in three hours.
10 After cooling the autoclave and removal of the
catalyst by ?ltration, cyclohexanethiol was iso
lated by distillation in an amount corresponding
to 80% of the theoretically possible conversion
from cyclohexanone. The sul?ded catalyst was
15 found to have a weight ratio of iron to sulfur of
1.73. The ratio calculated for FeS is 1.75. Example VI
The above experiment was carried out under
A ?nely divided alloy containing 25% of cobalt.
identical conditions except that ?nely divided py
25% of molybdenum, and 50% of aluminum was
rophoric cobalt prepared from a cobalt-aluminum
suspended in boiling water and treated with a 20 alloy by means of sodium hydroxide'was substi
solution of sodium hydroxide. After the alumi
tuted for the ?nely divided iron in the above ex
num had been dissolved the ?nely divided prod
ample. In this way there was again obtained
uct was ?ltered from the solution and washed
cyclohexanethiol in high yield.
several times with water. The active cobalt
Example IX
molybdenum so obtained was then transferred
to methanol and treated with hydrogen sul?de 26. By.‘ way of contrast the above experiment was
gas for several hours at room temperature. After
.duplicated except that a c0ba1t.sul?de catalyst
there was no further evolution of hydrogen the
prepared by the method disclosed in the patent
product was ?ltered and washed with water.
literature was used.
The catalyst so prepared was active in bringing 30
Seventy-?ve parts of CP cobaltic oxide was
about hydrogen reductions of which the follow
heated in a stream of hydrogen sul?de at a tem
ing is an example.
.
perature of 350° C. for 4 hours. The product was
A solution of 50 parts of sodium meta-bi
a dark grey, friable mass which was then ?nely
sul?te (NazSzOs) in 150 .parts of water was
' pulverized before use. Five parts of the cobalt
charged into an autoclave together with .10 parts 35 sul?de catalyst prepared in this manner was
'of the sul?ded cobalt-molybdenum catalyst, and
charged into an autoclave together with 60 parts
hydrogen was forced into the autoclave to a
of cyclohexanone and 30 parts of sulfur. The
pressure of 1500 lbs/sq. in. The autoclave was
autoclave was agitated and hydrogen was intro
heated to 75° C. and during 2 hours the pressure
duced to a pressure of 2,000 lbs. per sq. in.
decreased 400 lbs/sq. in Analysis of the reac 40 The autoclave was then heated to a temperature
tion product indicated that the sodium meta
of 150° C. for 3 hours, but during this period
blsul?te had been hydrogenated almost quanti
there was no apparent hydrogen absorption. The
tatively to sodium thiosulfate.
temperature was accordingly raised to 170° C.
and the pressure decrease was only 400 lbs. in 3
catalyst
NmEhOi + 2B:
—————O
N82810: + QHgO
hours.
No further hydrogen absorption was
noted. The contents of the autoclave were then
?ltered to separate thecatalyst and worked up as
Five grams of ?nely divided pyrophoricnickel
described above. The amount of thiol obtained
prepared by reducing nickel chloride with a solu- ‘
was only 0.022 moles, indicating that very little
tion of sodium naphthalene was charged into an
reaction had occured.
autoclave, together with 60 parts of sulfur and 50
The metal sul?des prepared according to this
90 parts of benzene. The autoclave was then
invention
are ‘active, as I have shown,‘ for the
charged with hydrogen to a pressure of 2200
hydrogenation of sulfur compounds. These cata
lbs/sq. in. and heated to 100° C. during 1/2 hour
lysts are, however, also active for hydrogenations
to convert the .pyrophoric nickel to the sul?de.
that do not involve sulfur compounds, as shown
55
The temperature was then raised to 125° C. vA
by the following examples.
rapid exothermic reaction occurred as evidenced
Example X
by the decrease in pressure. Reaction was com
plete in 2 hours. On examining the reaction
One hundred seventy-?ve parts of cottonseed
product, it was found that all of the sulfur had
been converted to hydrogen sul?de. The pyro 60 oil were charged to an autoclave, together with 10
_
Example]!!!
phoric nickel had likewise been converted to
nickel sul?de which catalyzes the hydrogena
tion reaction.
Example VIII
Sixty parts of cyclohexanone and 35 parts of
sulfur were charged into a pressure autoclave, 70
together with 5 parts of ?nely divided pyrophoric
iron prepared by extracting the aluminum from
parts of sulfided cobalt catalyst prepared by treat
ing ?nely divided pyrophoric cobalt with a ben
zene solution of sulfur at 25° C. until no further
sulfidation occurred. Hydrogen was admitted to
the autoclave to a. pressure of 3000 lbs/sq. in. and
'the autoclave heated to 225° C. After one hour
the absorption of hydrogen had ceased. On cool
ing the autoclave and ?ltering the hot reaction
mixture. the product was found to be-tristearin of
melting point 62° C.
.
.
Earample' XI
a ?nely powdered alloy of iron and aluminum
By way of contrast, the above ‘experiment was
with sodium hydroxide solution. . Hydrogen was
repeated using a cobalt sul?de catalyst prepared
admitted to the autoclave to a pressure of 2000 78 by the method described in thepatent literature.
1
9,408,088
Sixty parts of cobalt nitrate hexahydrate was
dissolved in 200 parts of water and stirred with an
excess of ammonium sul?de solution. The black
precipitate was ?ltered and washed free from sol
uble salts with water and then heated in a cur
rent of hydrogen‘sulilde at a temperature of 200°
C. for 12 hours. The black powder was then ?nely
ground. Fifteen parts of the cobalt sul?de pre
pared in this manner was charged into an auto
clave with 150 parts of cottonseed oil. Hy
drogen was then added to the autoclave to a pres
sure of 2,000 lbs. per sq. in. and the autoclave
heated to a temperature of 200° C. for 4 hours
;8
position of relatively unstable metal salts such as
formates and oxalates.
In preparing catalysts for use in liquid phase
.batch hydrogenation operations, it is preferable‘
that the metal be in ?nely divided form so as to
yield the metal sul?de in ?nely divided and active
condition. If the catalysts are to be used for con
tinuous hydrogenation reactions, then it is pref
erable that the metal sul?de be in rigid form, such
as pellets, briquets, lumps, and the like. Such
catalysts may be obtained by briquetting the
?nely divided metal sul?des. Alternatively, suit
able rigid metal sul?des may be prepared accord
with agitation, During this period very slight
ing to this invention by treating lumped or pel—
absorption of hydrogen was apparent. The con 15 leted forms having a surface of active metal with
the sul?ding agent.
- tentsi?ofthe autoclave were ?ltered from the cata
lyst?'The product obtained in this manner was
To effect the conversion of active‘ metal to
“la; lii‘quid" at "ordinary temperatures._ It had an
> metal sul?de, I have referred to theme of sulfur
jjjgdihe" number of 89, indicating that very little
and hydrogen sul?de, However, certain other
“hydrogenation had occurred.
7 20 divalent'sulfur compounds may be substituted for
a. 1,.
_
Example XII
these as, for ‘example, cabon bisul?de and mer
captans. These compounds may be termed sul?d
ing agents. The sul?dation is carried out below
350” C. and generally below 150° C. because at the
" " Fifty-four ‘parts of p-benzoquinone, 100 parts
‘of benzene solvent and 10 parts of sul?ded cobalt
catalyst prepared as described in Example I were 26 higher temperatures it is dimcuit to prevent loca1
charged into an autoclave, together with hydro
gen'at 2500 lbs/sq. in.'_p'ress . Onheatingthe
autoclave to 125°‘ C.,‘ the abso tion of hydrogen
' commenced.
After‘two hours, no further reac
superheating of the catalyst surface due to the
exothermic nature of the reaction of the’ active
metal with the sul?ding agent. This results in
sintering and loss of catalytic activity. I will
tion occured. The cooled reaction mixture was 30 usually operate at temperatures below 150° C.
?ltered from the catalyst. Evaporation of the
and preferably within the range from 25 to 100°
benzene solvent yielded crystalline‘ hydroquinone. ,
C. After the catalyst is formed it is stable at
temperatures much higher than can be used dur
. Example XIII
ing the preparation of the metal sul?de. ‘The
Finely divided pyrophoric cobalt was treated 35 sul?ding treatment may be carried out at atmos
several times at 25-30° C. with a saturated ben
pheric pressure or at higher pressures as'I have
zene solution of sulfur. The sulfided cobalt was
illustratedin the foregoing examples. The treat
?ltered from the benzene solution and treated
ment of active metals with sulfur compounds may
with .20 times its ‘weight of boiling 10% aqueous
be carried out in the absence of other materials,
sulfuric acid for 2' hours to dissolve any remain 40 but it is preferable to carry out the reaction in
ing metallic cobalt. The cobalt sul?de catalyst
was. then filtered and washed with water and
the presence of a solvent or diluent for the sul
fur compound, which serves to moderate the vio
?nally with methanol.
,
‘
I
lence of the reaction and to maintain the tem
One hundred parts of nitrobenzene dissolved
perature within the desired range. As examples
in an equal weight ‘of methanol was charged into 45 of liquids that may be used in this connection,
a hydrogenation autoclave, together with 33v parts
I may mention alcohols such as methanol and
of sul?ded'cobalt catalyst prepared as described
ethanol, ethers such as diethyl ether, hydrocar
above. Hydrogen was admitted to the‘autoclave
bons such as petroleum fractions, benzene and the
to a pressureof 1500 ,1bs./sq. in. and the auto
like. Examples of diluents that may be used for
clave heated to1125-150° C. Rapid absorption of
gaseous sul?ding agents are nitrogen, hydrogen
hydrogen occurred and was completed after a few
and carbon dioxide. The extent‘ of the sul?ding
‘ hours. The reaction product was aniline.
treatment may vary, it being only necessary to
While _I have indicated in the'foregoing exam
convert the surface of the metal particles to the
ples certain metals that may be, sul?ded to form
metal sul?de. In general, however, I prefer to
‘active catalysts according to this, invention the as continue the sul?ding treatment until no more
method'may be applied with good results to other
sulfur is‘ taken up by the metal. In many in
metals. In general,‘ the common hydrogenating
stances the sul?dation can be ‘completed in less
metals are suitable materials for preparing metal
than one hour but longer periods of treatment
sul?de catalysts. For example, I may use besides
may be required. As outlined in‘ the foregoing
the ferrous metals, other metals such as tungsten,
examples, it is convenient in many cases to com
chromium, cadmium, lead and palladium. These
bine the sul?ding treatment with the actual use
- metals may likewise be used in combination with
of the catalyst in a hydrogenation reaction, thus
eachv ‘other as suitable materials for preparing
enabling both operations to be carried out in'the
same equipment, This is accomplished by charg
tion. Several methods may be employed to ob
ing the active metal and the sul?ding agent into
tain metals in su?iciently active form for use
the hydrogenation autoclave together with hy
according to this invention. In general, any of
drogen and the material to be hydrogenated. The
I‘ the common methods used for preparing catalytie
active metal will then be converted to the metal
‘_c"
' ctive or pyrophoric metals are suitable.
sul?de‘catalyst during the time in which the au
such methods I may employ are (1) ex 70 toclave is heated to the desired hydrogenation
traction of one or more components from an alloy
temperature and the presence of the material to
of the desired metal under conditions such that
be hydrogenated will serve to vmoderate the sul
the latter is not attacked; (2) reduction of a
?dation reaction and prevent overheating.
the sulfactive catalysts according to this inven
metal compound to ‘the free metal by hydrogen
or other reducing agents; or (3) thermal decom
The metal sul?des prepared according to this‘
invention may be used for catalytic hydrogena
2,402,0as
_
10
9
tions in substantially pure form or they may con
providing for the removal of the heat of reaction
stitute only a part of the entire catalyst and other
materials as, for example, metals,-metal oxides,
or other compoundsmay be present. It is fre
quently desirable to extend the metal sul?de on
an inert support such as kieselguhr, alumina,
magnesia, silica gel, and the like. If it is desired
so as to maintain the temperature of the react
ing mass below 150° (7., thereby forming a metal
to use pure metal sul?de, any unreacted metal or
sul?de , catalyst.
'
.
g
2. The process which comprises bringing into
admixture a hydrogenating metal in ?nely di
vided activated form, a sul?ding agent, hydrogen,
and a compound to be hydrogenated, elevating
the temperature of said mixture until hydrogen
usually'by extracting the sul?ded metal with di 10 a'tion begins, thereby prior to said hydrogenation
, metal oxide that may be present can be removed
preforming in said mixture, under conditions
providing for the removal of the heat of reaction
so as to maintain the temperature of the react
ing mass below 150° 0., the sul?de of said metal
alytic activity by this treatment.
in a catalytic form.
The use of metal sul?des prepared according
3. A metal sul?de hydrogenation catalyst that
to this invention as catalysts for hydrogenation
is active at relatively low temperatures and in
reactions also constitutes a part of this inven
the presence of sulfur containing compounds,
tion.
said catalyst being identical with the product
The metal sul?des prepared according to this
invention are used for catalyzing the hydrogen 20 obtained by bringing a hydrogenating metal in
?nely divided activated form into ‘contact with,
reduction of a variety of sulfur compounds. For
a sul?ding agent under conditions providing for
example, organic disul?des, polysul?des, thioe
the removal of the heat of reaction so as to main
aldehydes. thioketones, sul?nic and sulfonic acid
tain the temperature of the reacting mass below
derivatives are hydrogenated to the correspond
.
ing thiols in the presence of these catalysts. The 25 150° C.
4. The process in accordance with claim 1 char
catalysts are likewise useful for the hydrogena
acterized in that the ?nely divided activated hy
tion of nonsulfurlunsaturated groups where sul
drogenating metal is obtained by the extraction
fur or sulfur compounds are present that ‘would
of the other components of analloy of the metal
poison the usual hydrogenating catalysts.‘ Asv
examples, there may be mentioned the hydrogen 30 under conditions such that the said metal is not
ation of aldehydes and ketones to the correspond
5. The process in accordince with claim 1 char
ing alcohols, saturation of ethylenic and acetylenic
acterized in that the ?nely divided activated hy
derivatives and hydrogenation of nitro com
drogenating metal is obtained by the reduction of
pounds to the corresponding amines. The cat- -
lute mineral or organic acids, as in many cases
the metal sul?des are not attacked by dilute acid
at moderate temperatures and do not lose c'at
attacked.
‘ alysts are also useful for the hydrogenation of
nitrates, nitrites, sul?tes and bisul?tes. Many
of the metal sul?des prepared according to this
.
_
- a compound of the metal to the free metal by
means of hydrogen.
6. The process in accordance with claim 1 char
acterized in that the ?nely divided activated hy
invention are active catalysts even in the pres
drogenating metal is obtained by the thermal de
ence of acids and alkalis, and can therefore be.
used when acid or alkaline conditions exist dur 40 composition of a relatively unstable salt of the
ing hydrogenation reactions.
Y
metal.
The hydrogenation catalysts prepared by the
.
'
7. The process in accordance with claim 1 char
method described herein have two important
properties: (1) The catalysts are active‘ at low
temperatures; (2) the catalysts are immune to
acterized in that after the metal, sul?de catalyst >
poisoning by sulfur‘ or'sulfur compounds. This
with a dilute acid under non-oxidizing conditions.
8. The process in accordance with claim 1 char
acterized in that the reaction is carried out in an
combination of properties enables one to obtain
a wide variety of valuable organic thiol com-'
pounds by simple and e?icient catalytic proc
cases where hitherto ‘complicated procedures were
generally required. The hydrogenation reactions
can be effected using these catalysts so that simple
hydrogen addition and vhydrogen reduction takes
is formed, any unreaoted metal present in the
catalytic mass is removed by treating said mass
inert liquid medium.
9. The process for the preparation of a catalyst
which comprises bringing a hydrogenating metal
in ?nely divided activated form, said metal being
selected from the class consisting of iron, cobalt,
place without disruptive side reactions occurring. - nickel and molybdenum, into intimate contact
Pure compounds can thus be obtained in high 55 with a sul?ding agent under conditions provid
ing for the removal of the heat of reaction so as
yields rather than complicated mixtures which
to maintain the temperature of the reacting mass
require expensive re?ning operations. '
below 150° (3., thereby producing a metal sul?de '
It is apparent that many widely different em
catalyst.
.
bodiments of this invention may be made with
10. The process in accordance with claim 9
out departing from the spirit and scope thereof 60
characterized in that the sul?ding agent is se
and therefore it is not intended to be limited ex
lected from the group consisting of sulfur and
cept as indicated in the appended claims.
I claim:
-
hydrogen sul?de.
,
11. The process in accordance with claim 9
81881? which comprises bringing a hydrogenating 65 characterized in that the reaction is carried out
at a temperature between 25° and 100° C.
metal in a ?nely divided activated form into
1. The process for the preparation or a cat
I contact with a sul?ding agent under conditions,
FRANK KERR /BIGNAIGO.
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