CA1088502A - Process for the preparation of supported catalysts - Google Patents
Process for the preparation of supported catalystsInfo
- Publication number
- CA1088502A CA1088502A CA277,315A CA277315A CA1088502A CA 1088502 A CA1088502 A CA 1088502A CA 277315 A CA277315 A CA 277315A CA 1088502 A CA1088502 A CA 1088502A
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- catalyst
- carbon
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-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/30—Ion-exchange
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/16—Reducing
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- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Catalysts (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Inert Electrodes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
.
Process for preparing supported catalysts to be used in heterogeneous-catalytical or electro-catalytical processes, by exchanging protons of acid groups on active carbon with cations from a solution of a compound of a catalytically active metal and separating the treated mass from the solution, characterized in that the catalyst is used in the medium of the reaction catalyzed by the catalyst, without separate reduction of said catalyst. This process gives an active metal-on-carbon catalyst in which the metal particles are deposited as small crystallites, whilst avoiding cumbersome, known methods.
.
Process for preparing supported catalysts to be used in heterogeneous-catalytical or electro-catalytical processes, by exchanging protons of acid groups on active carbon with cations from a solution of a compound of a catalytically active metal and separating the treated mass from the solution, characterized in that the catalyst is used in the medium of the reaction catalyzed by the catalyst, without separate reduction of said catalyst. This process gives an active metal-on-carbon catalyst in which the metal particles are deposited as small crystallites, whilst avoiding cumbersome, known methods.
Description
~ 2809 C~
The lnvention relates to a process to be used ln heterogeneously-catalyzed or electrochemical-catalyzed processes for preparlng supported catalysts by exchanging protons oi acid groups ot actlve carbon with cations irom a ~olutlon oi a compound oY a catalytlcally actlve metal and separatlng the treated mass lrom the solutlon.
Furuoya and collaborators descrlbed a method ior prep~rlng pa11ad~um-on-carbon catalysts, in whlch the palladlum 19 depo~lted ag J-al1 metal crystallites (Intern. Chemlcal Englneerlng 10, no 21, Aprll 1970, pp. 333-338) This method provides ior oxidl$ing the actlve carbon with nitric acid, lmpregnatlng the oxidlzed oarbon ior 48 hours with an aqueous solution oi a palladlum-ammlne complex, during which operation protons iorm the carbon suriace are exchanged agalnst posltlvQ palladium-ammine complex ions, isolating the lmpregnated solid mass by rlltration, and subsequently washlng and drying lt. Following this, the catalyst is actlvated by treating lt in succes~icn wlth hydrogen at 300 & ior 3 hours, wlth alr at 150 C ior 1 hour and, iinally, once more with hydrogen at 150 C ior 10 minutes, ffl ls method has the drawback Or being laborlous. Moreover, carbon oxidized with nitric acid in extremely diiiicult to iilter. The low activlty suggests that coarse metal crystallites may have iormed.
Catalysts ln whlch the catalytlcally active metal is deposlted a9 small crysatllltes can also be prepared by the method described in Applicant's Canadia~ patent application 247~496 This procedure yields a catalyst oi high ~atalytlc activity, by start~ng ~rom an active aarbon with a given ~avourable pore distrlbution to which a salt oi a catalytically active metal is adsorbed in an aqueous medlum and by periorming the hydrolysls and reduction oi' the resulting oxide or hydroxide in one single step with a mixture oi liquld hydrolyzlng and reduclng agent9.
It has been iound that Furuoya'~ process can be carried out in a ~ -much simpler way, whilst yielding a catalyst oi equivalent quallty but oi improved iiltration bebavlour, whloh, moreover, can be direotly applied without requiring the ~airly oomplioated reduclng treatment.
The lnvention relates to a process to be used ln heterogeneously-catalyzed or electrochemical-catalyzed processes for preparlng supported catalysts by exchanging protons oi acid groups ot actlve carbon with cations irom a ~olutlon oi a compound oY a catalytlcally actlve metal and separatlng the treated mass lrom the solutlon.
Furuoya and collaborators descrlbed a method ior prep~rlng pa11ad~um-on-carbon catalysts, in whlch the palladlum 19 depo~lted ag J-al1 metal crystallites (Intern. Chemlcal Englneerlng 10, no 21, Aprll 1970, pp. 333-338) This method provides ior oxidl$ing the actlve carbon with nitric acid, lmpregnatlng the oxidlzed oarbon ior 48 hours with an aqueous solution oi a palladlum-ammlne complex, during which operation protons iorm the carbon suriace are exchanged agalnst posltlvQ palladium-ammine complex ions, isolating the lmpregnated solid mass by rlltration, and subsequently washlng and drying lt. Following this, the catalyst is actlvated by treating lt in succes~icn wlth hydrogen at 300 & ior 3 hours, wlth alr at 150 C ior 1 hour and, iinally, once more with hydrogen at 150 C ior 10 minutes, ffl ls method has the drawback Or being laborlous. Moreover, carbon oxidized with nitric acid in extremely diiiicult to iilter. The low activlty suggests that coarse metal crystallites may have iormed.
Catalysts ln whlch the catalytlcally active metal is deposlted a9 small crysatllltes can also be prepared by the method described in Applicant's Canadia~ patent application 247~496 This procedure yields a catalyst oi high ~atalytlc activity, by start~ng ~rom an active aarbon with a given ~avourable pore distrlbution to which a salt oi a catalytically active metal is adsorbed in an aqueous medlum and by periorming the hydrolysls and reduction oi' the resulting oxide or hydroxide in one single step with a mixture oi liquld hydrolyzlng and reduclng agent9.
It has been iound that Furuoya'~ process can be carried out in a ~ -much simpler way, whilst yielding a catalyst oi equivalent quallty but oi improved iiltration bebavlour, whloh, moreover, can be direotly applied without requiring the ~airly oomplioated reduclng treatment.
- 2 -' 10~850~
The present invention is directed to preparing an active metal-on-carbon catalyst in which the metal particles are deposited as small crystallites, whilst avoiding the cumbersome preparation method of Furuoya.
According to the invention, there is provided a process for preparing supported catalysts to be used in heterogeneous-catalytical or electro-catalytical processes, by exchanging protons of acid groups on acti~e carbon with cations from solutions of one or more of the salts or complex compounds of the metals of Groups I B and YIII of the Periodic System of Elements and Zn and separating the treated catalyst mass from the solution, the catalyst being reduced in the medium of the reaction catalyzed by the catalyst, without separate reduction of said catalyst. The cations may e.g.
originate from one or several salts or complex compounds of notably of Ag, Au, Co, Cu, Fe, Ir, Ni, Os, Pd, Pt, Rh, Ru as well as Zn.
For the supporting material use must be made of carbon containing acid surface groups. Some active carbons that can be used for the purpose are commercially available, ant are known as hydrophilic active carbon, or as active carbon suited for treatment of liquids. The acidity of these carbons and the number of acid groups on their surfaces can be determined titrimetrically, as is stated by B.R. Puri in "Chemistry and Physics of Carbon", published by Marcel Dekker, New York, 1970, Chapter 6, pp 229 ff.
It is possible to increase the number of acid groups on the -~
supporting surface, if a high degree of loading should be desirable, by subjectlng the carbon to a known oxidative treatment with oxygen, ozone, hydrogen peroxide, potassium persulphate, potassium nitrate, nitrogen monoxide or nitrogen dioxide. In the preparation of the present catalyst, increasing the number of acid groups can be performed the most adequately by treating the carbon with hydrogen peroxide. Application of this compound, combined with an appropriate choice of the duration of the treatment and the temperature at which it is carried out, enables the number of acid groups to be controlled at discretion and ensures that the coal will retain good fil~ration properties. The treatment is all the more important in those
The present invention is directed to preparing an active metal-on-carbon catalyst in which the metal particles are deposited as small crystallites, whilst avoiding the cumbersome preparation method of Furuoya.
According to the invention, there is provided a process for preparing supported catalysts to be used in heterogeneous-catalytical or electro-catalytical processes, by exchanging protons of acid groups on acti~e carbon with cations from solutions of one or more of the salts or complex compounds of the metals of Groups I B and YIII of the Periodic System of Elements and Zn and separating the treated catalyst mass from the solution, the catalyst being reduced in the medium of the reaction catalyzed by the catalyst, without separate reduction of said catalyst. The cations may e.g.
originate from one or several salts or complex compounds of notably of Ag, Au, Co, Cu, Fe, Ir, Ni, Os, Pd, Pt, Rh, Ru as well as Zn.
For the supporting material use must be made of carbon containing acid surface groups. Some active carbons that can be used for the purpose are commercially available, ant are known as hydrophilic active carbon, or as active carbon suited for treatment of liquids. The acidity of these carbons and the number of acid groups on their surfaces can be determined titrimetrically, as is stated by B.R. Puri in "Chemistry and Physics of Carbon", published by Marcel Dekker, New York, 1970, Chapter 6, pp 229 ff.
It is possible to increase the number of acid groups on the -~
supporting surface, if a high degree of loading should be desirable, by subjectlng the carbon to a known oxidative treatment with oxygen, ozone, hydrogen peroxide, potassium persulphate, potassium nitrate, nitrogen monoxide or nitrogen dioxide. In the preparation of the present catalyst, increasing the number of acid groups can be performed the most adequately by treating the carbon with hydrogen peroxide. Application of this compound, combined with an appropriate choice of the duration of the treatment and the temperature at which it is carried out, enables the number of acid groups to be controlled at discretion and ensures that the coal will retain good fil~ration properties. The treatment is all the more important in those
3 -~0~8s02 cases where it is desired to deposit larger quantities of metal on the support by means of ion-exchange.
In the manner described above, metals forming positive ions in solution can be deposited on a support carrying acid groups. Also complex ,.:, - 1, ' : .
: ~ :` ` `
.
- 3a -1~ "
10~8S~
lons, lr carrylng a po~ltive ohargo, can`th~ be oxehang~d galnse aold grou on the ~uriace ot the ~upport.
The process o~ the lnvention can also be u~ed ior preparing alloyed catalysts, starting ~rom solutions oi mixtures Or salts or co~ples compounds of the catalytically actlve metals. Ion exchange with the cld surrace groups results in a statistlc dlstrlbutlon oi tho alloy-tor~lng lon~
on the suriace Or the support, and i'ormatlon oi homo~cneous alloy partlol-~.
Ii the compound to be exchanged, tor example a complox lo,n, 19 ~se-ptlbl-to the aotlon of acid, and is llable to decompose under the iniluenes oi the acld surtace o~ the support, one can ~lrst exchange the acld group~ agalnst alkall metal lons, and subsequently exchsnge the alkali metal lons agaln-~t the posltlve lons Or the catalytlcally actlve compound.
m e amount ot metal that can be deposlted on the suriace oi the support by exchanging aeld groups agalnst posltlve metal lons mar be varled wlthln wlde llmlts, lor example irom 0.1 to approxlmately 10% wt ealeulated to the weieht oi the ultlmate catslyst. ~he rlgure shows the tltratlon curve lor several actlve carbon types as a measure o~ the number Or acld groups.
e number Or meq ~a(OH)2 needed ior neutrallzlng a slurry o~ 100 g ac~tlve carbon ln distllled water 19 plotted on the absclssa, and the ~H value ~20 on the ordlnate. It can be derlved ~rom thls plot tbat type CX aetlve carbon msde by CECA, Frsnce, possesses a large numbei Or acld groups.
Practlce has shown that up to a ralrly degree Or loadlng thls sctlve earbon type 19 a su~ted support ior preparing catalysts accordlng to the invention. However, arter this active carbon type has been troated ~25 with H202 at 40 & ror 20 hours, more aeld groups appear to he present, wlth the eonsequenee that exchango wlth a Pd(NH3)4 C12-solution and , ~:
~ reduction yields a cataly~t whlch contalns approximately 5% wt o~
~ :
psllsdium; lnstead Or 2X wt wlth the untreatod aetlvo earbon. ~`
The qusntity Or catalytlcally actlve materlal to be deposlted by exchange ~30 ¢an be determlned by mean~ ~f the abovenentloned titratlon curve~ m e degree o~ loadlng wlth catalytlcally aetlve metal eorresponds with the nu~ber Or ~urrace proton~, ~hlch 1~ detenslned ~ro~ the nu ber Or ~q.
8h(0H)2~100 B carbon durlng neutrallzatlon to a pH Or approxi ately 7.
Uslng the process oi the lnventlon, skin-t~pe cataly~tq osn al-~o be prepared ln an eriiclent manner irom granules, pellets or other S arte~acts conslstlng oi actlve carbon or materlal containlng actlve carbon, by cub~ectlng sald granules, pellets or other arteiacts to the exchsnge and sub~equent reductlon treatments descrlbed above. 8y the 'ter~ actlve oarbon' 19 to be understood all CU-QtOmary actlve carbon type-~, such a~ carbon prepared irom peat, coal, bone etc, but al~o grsphlte and osrbon blaok, provided all these type-~ carry acid group~ on thelr quriaoe. ~ ;
me catalysts acoordlng to the lnventlon can be employed ln hydrogenatlon processes, ln whlch case the treatment ior reduclng the metal -~
lon to the iree metal may be carrled out ln ~ltu. Palladium-on-c~rbon, platlnum-on-carbon or platlnum-pallad~um-on-carbon cataly-~ts made aacordlng ~5 to the invention are very sulted ior catalyzlng the preparatlon Or hydroxyl-a~ine by reductlon or nltrate lons or nltrogen monoxlde with hydrogen ln .
a strongly acid medium. m e carbon treated ~lth the noble-metal complex can be immedlately employed ln the reaction medlum. Previous reduction 1~ no .
;i longer nece-~sary. ``
Accordlng to the lnventlon electrodes ior iuel cells can be prepared, notably noble metal-on-carbon electrodes.
ffl e invention will be rurther elucldated with reierence to the ; ~ollowing example without, however, belng restrlcted thereto.
~' ` `
20 B 0~ active carbon, make CECA, France, type CX, with an acc-#~ble suriace area (EET area) o~ lOS5 m /g wa~ ~tlrred with 120 ml oi ~`
dlstllled water ior V2 hour ln order to expel atr and other ad~orbed ga5e~.
Next, 105 ml oi a palladlum a nine chloride, Pd(NH3)4C12, solutlon contalning 2.2 g o~ palladlum (calculated as metal) were added, whereupon the solutlon ~ ..
30~ wa3 stlrred ior 20 h at room temperature to exchange suriace protons agalnst _ 5 _ 1~85~
Pd(NI13)~ lons Sub~oquently, t~e solld m-99 was separated by iiltr-tlon, and drled ior 6 hours at 60-70 C. One ~l$th Or the palladluo ln the solutlon deposlted on the active carbon. ~ecause there is only exchange on ~he suriace oi the active coal, no adsorption occurs.
The solutlon may have thereiore a highe- concentration oi Pd(NH3)4 -ionY
than that i9 necessary i'or the exchange.
With the aid oi the catalyst prepared ln thls way several experl ents were carried out:
a. A minor portion oi the catalyst was sub~ected to basic hydrolysis and reduction with alkallne methanol. m ls experlment dld not yleld a sultable catalyst because the dissolved palladium particles were present ln colloidal iorm.
~ b. Another portlon oi the catalyst was used, without iurther previous ; treatment, ior the catalyzed preparation oi hydroxylamlne irom nitrate lons at 30 &. To thls end hydrogen gas (80 l/h) was ied lnto one lltre oi an aqueous buiier solution which contalned 207 cm o$ phosphorlc acid (85%-conoentration), 82 g oi sodlum hydroxide and 198 g Or NaN03, whereupon 750 mg oi the catalyst was added and dlspersed by sti~rrlng. The activity oi the catalyst was measured and expressed in g oi hydroxylamine per g oi metal/hour. m e result o$ the measurements is given in the table, exp. no. 1.
c. A small portion oi the catalyst was reduced with hydrogen gas prior to appllcation. To this end, nitrogen gss containing 1 vol-% Or hydrogen gas was passed over it at the rate Or 20 l/h in a pyrex~glass tube at 300 &
ior 1 hour. m e ~eduction was then continued ior 1 hour at 300 C with a mixture oi 50% vol. oi nitrogen gas and 50% vol. oi hydrogen gas, supplied at the rate di 20 l/h, aiter which coolin~ was eiiected to room temperature in a stream o$ pure nitrogen. The meAsurlng results are shown in the table, Exp no. 2.
For the purpose Or ¢omparison catalysts were prepared according to the process oi the Canadia~ patent application 247,496, stArting rrom the iollowing aotlve carbons. CECA type CX, Carbopuron type 4N, ' :
~ Trade mark 10~8502 Carbopouron type 4N without basic hydrolysis and reduction, and Norit type SX 2 in which latter case the reduction was carried out with hydrogen (experiments 4, 5, 6 and ~ Likewise for comparison, a catalyst was prepared according to the method described by Furuoya. The result obtained with this catalyst is shown in the Table, exp. no. 3.
i Table xp.
no. Catalyst preparationBET surface Acidity Activity g NH20H/g area (m2/g) Pd/h 1. 1.9% wt Pd as Pd(NH3)4 1055 strongly acid 24.5 present on CECA CX, prepared according to the invention 2 1.9~ wt Pd on CECA CX* pre-1055 strongly acid 20.5 pared by ion exchange and i separate reduction with H2 i at 300C
3 10.7% wt Pd on CECA CX* prepared -according to the method described 1055 strongly acid 2.6 by Furuoya `
~, ,
In the manner described above, metals forming positive ions in solution can be deposited on a support carrying acid groups. Also complex ,.:, - 1, ' : .
: ~ :` ` `
.
- 3a -1~ "
10~8S~
lons, lr carrylng a po~ltive ohargo, can`th~ be oxehang~d galnse aold grou on the ~uriace ot the ~upport.
The process o~ the lnvention can also be u~ed ior preparing alloyed catalysts, starting ~rom solutions oi mixtures Or salts or co~ples compounds of the catalytically actlve metals. Ion exchange with the cld surrace groups results in a statistlc dlstrlbutlon oi tho alloy-tor~lng lon~
on the suriace Or the support, and i'ormatlon oi homo~cneous alloy partlol-~.
Ii the compound to be exchanged, tor example a complox lo,n, 19 ~se-ptlbl-to the aotlon of acid, and is llable to decompose under the iniluenes oi the acld surtace o~ the support, one can ~lrst exchange the acld group~ agalnst alkall metal lons, and subsequently exchsnge the alkali metal lons agaln-~t the posltlve lons Or the catalytlcally actlve compound.
m e amount ot metal that can be deposlted on the suriace oi the support by exchanging aeld groups agalnst posltlve metal lons mar be varled wlthln wlde llmlts, lor example irom 0.1 to approxlmately 10% wt ealeulated to the weieht oi the ultlmate catslyst. ~he rlgure shows the tltratlon curve lor several actlve carbon types as a measure o~ the number Or acld groups.
e number Or meq ~a(OH)2 needed ior neutrallzlng a slurry o~ 100 g ac~tlve carbon ln distllled water 19 plotted on the absclssa, and the ~H value ~20 on the ordlnate. It can be derlved ~rom thls plot tbat type CX aetlve carbon msde by CECA, Frsnce, possesses a large numbei Or acld groups.
Practlce has shown that up to a ralrly degree Or loadlng thls sctlve earbon type 19 a su~ted support ior preparing catalysts accordlng to the invention. However, arter this active carbon type has been troated ~25 with H202 at 40 & ror 20 hours, more aeld groups appear to he present, wlth the eonsequenee that exchango wlth a Pd(NH3)4 C12-solution and , ~:
~ reduction yields a cataly~t whlch contalns approximately 5% wt o~
~ :
psllsdium; lnstead Or 2X wt wlth the untreatod aetlvo earbon. ~`
The qusntity Or catalytlcally actlve materlal to be deposlted by exchange ~30 ¢an be determlned by mean~ ~f the abovenentloned titratlon curve~ m e degree o~ loadlng wlth catalytlcally aetlve metal eorresponds with the nu~ber Or ~urrace proton~, ~hlch 1~ detenslned ~ro~ the nu ber Or ~q.
8h(0H)2~100 B carbon durlng neutrallzatlon to a pH Or approxi ately 7.
Uslng the process oi the lnventlon, skin-t~pe cataly~tq osn al-~o be prepared ln an eriiclent manner irom granules, pellets or other S arte~acts conslstlng oi actlve carbon or materlal containlng actlve carbon, by cub~ectlng sald granules, pellets or other arteiacts to the exchsnge and sub~equent reductlon treatments descrlbed above. 8y the 'ter~ actlve oarbon' 19 to be understood all CU-QtOmary actlve carbon type-~, such a~ carbon prepared irom peat, coal, bone etc, but al~o grsphlte and osrbon blaok, provided all these type-~ carry acid group~ on thelr quriaoe. ~ ;
me catalysts acoordlng to the lnventlon can be employed ln hydrogenatlon processes, ln whlch case the treatment ior reduclng the metal -~
lon to the iree metal may be carrled out ln ~ltu. Palladium-on-c~rbon, platlnum-on-carbon or platlnum-pallad~um-on-carbon cataly-~ts made aacordlng ~5 to the invention are very sulted ior catalyzlng the preparatlon Or hydroxyl-a~ine by reductlon or nltrate lons or nltrogen monoxlde with hydrogen ln .
a strongly acid medium. m e carbon treated ~lth the noble-metal complex can be immedlately employed ln the reaction medlum. Previous reduction 1~ no .
;i longer nece-~sary. ``
Accordlng to the lnventlon electrodes ior iuel cells can be prepared, notably noble metal-on-carbon electrodes.
ffl e invention will be rurther elucldated with reierence to the ; ~ollowing example without, however, belng restrlcted thereto.
~' ` `
20 B 0~ active carbon, make CECA, France, type CX, with an acc-#~ble suriace area (EET area) o~ lOS5 m /g wa~ ~tlrred with 120 ml oi ~`
dlstllled water ior V2 hour ln order to expel atr and other ad~orbed ga5e~.
Next, 105 ml oi a palladlum a nine chloride, Pd(NH3)4C12, solutlon contalning 2.2 g o~ palladlum (calculated as metal) were added, whereupon the solutlon ~ ..
30~ wa3 stlrred ior 20 h at room temperature to exchange suriace protons agalnst _ 5 _ 1~85~
Pd(NI13)~ lons Sub~oquently, t~e solld m-99 was separated by iiltr-tlon, and drled ior 6 hours at 60-70 C. One ~l$th Or the palladluo ln the solutlon deposlted on the active carbon. ~ecause there is only exchange on ~he suriace oi the active coal, no adsorption occurs.
The solutlon may have thereiore a highe- concentration oi Pd(NH3)4 -ionY
than that i9 necessary i'or the exchange.
With the aid oi the catalyst prepared ln thls way several experl ents were carried out:
a. A minor portion oi the catalyst was sub~ected to basic hydrolysis and reduction with alkallne methanol. m ls experlment dld not yleld a sultable catalyst because the dissolved palladium particles were present ln colloidal iorm.
~ b. Another portlon oi the catalyst was used, without iurther previous ; treatment, ior the catalyzed preparation oi hydroxylamlne irom nitrate lons at 30 &. To thls end hydrogen gas (80 l/h) was ied lnto one lltre oi an aqueous buiier solution which contalned 207 cm o$ phosphorlc acid (85%-conoentration), 82 g oi sodlum hydroxide and 198 g Or NaN03, whereupon 750 mg oi the catalyst was added and dlspersed by sti~rrlng. The activity oi the catalyst was measured and expressed in g oi hydroxylamine per g oi metal/hour. m e result o$ the measurements is given in the table, exp. no. 1.
c. A small portion oi the catalyst was reduced with hydrogen gas prior to appllcation. To this end, nitrogen gss containing 1 vol-% Or hydrogen gas was passed over it at the rate Or 20 l/h in a pyrex~glass tube at 300 &
ior 1 hour. m e ~eduction was then continued ior 1 hour at 300 C with a mixture oi 50% vol. oi nitrogen gas and 50% vol. oi hydrogen gas, supplied at the rate di 20 l/h, aiter which coolin~ was eiiected to room temperature in a stream o$ pure nitrogen. The meAsurlng results are shown in the table, Exp no. 2.
For the purpose Or ¢omparison catalysts were prepared according to the process oi the Canadia~ patent application 247,496, stArting rrom the iollowing aotlve carbons. CECA type CX, Carbopuron type 4N, ' :
~ Trade mark 10~8502 Carbopouron type 4N without basic hydrolysis and reduction, and Norit type SX 2 in which latter case the reduction was carried out with hydrogen (experiments 4, 5, 6 and ~ Likewise for comparison, a catalyst was prepared according to the method described by Furuoya. The result obtained with this catalyst is shown in the Table, exp. no. 3.
i Table xp.
no. Catalyst preparationBET surface Acidity Activity g NH20H/g area (m2/g) Pd/h 1. 1.9% wt Pd as Pd(NH3)4 1055 strongly acid 24.5 present on CECA CX, prepared according to the invention 2 1.9~ wt Pd on CECA CX* pre-1055 strongly acid 20.5 pared by ion exchange and i separate reduction with H2 i at 300C
3 10.7% wt Pd on CECA CX* prepared -according to the method described 1055 strongly acid 2.6 by Furuoya `
~, ,
4 7% wt Pd on CECA CX* prepared 1055 strongly acid 18.9 according to Neth. patent application 7,502,968 9.4% wt Pd on Carbopuron 4N* 895 weakly acid 19.9 prepared according to Neth.
patent application 7,502,968 6. 9.4% wt Pd on Carbopuron 4N* 895 weakly acid 6.3 - prepared according to Neth.
patent application 7,502,968 but with omission of the basic hydrolysis and reduction 7 10.6% wt Pd on Norit SX-2* 1090 weakly acid 6.7 prepared according to Neth.
~ patent application 7,502,968 d ~ but with H2-reduction at 300C
~- Comparison of the results of experiment 1 (accordlng to the invention) with ~ :.
~-~; those of the other experiments ~accorting to known processes) shows that ; the process of the invention yields the most catalyst.
* Trade Mark I~ ~
, ~. ,,
patent application 7,502,968 6. 9.4% wt Pd on Carbopuron 4N* 895 weakly acid 6.3 - prepared according to Neth.
patent application 7,502,968 but with omission of the basic hydrolysis and reduction 7 10.6% wt Pd on Norit SX-2* 1090 weakly acid 6.7 prepared according to Neth.
~ patent application 7,502,968 d ~ but with H2-reduction at 300C
~- Comparison of the results of experiment 1 (accordlng to the invention) with ~ :.
~-~; those of the other experiments ~accorting to known processes) shows that ; the process of the invention yields the most catalyst.
* Trade Mark I~ ~
, ~. ,,
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Process for preparing supported catalysts to be used in hetero-geneous-catalytical or electro-catalytical processes, by exchanging protons of acid groups on active carbon with cations from solutions of one or more of the salts or complex compounds of the metals of Groups I B and VIII of the Periodic System of Elements and Zn and separating the treated catalyst mass from the solution, the catalyst being reduced in the medium of the reaction catalyzed by the catalyst, without separate reduction of said catalyst.
2. Process according to claim 1, characterized in that the number of acid groups on the surface of the support is increased by a treatment with hydrogen peroxide.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL7604669A NL7604669A (en) | 1976-05-01 | 1976-05-01 | PROCEDURE FOR PREPARING CARRIER CATALYSTERS. |
| NL7604669 | 1976-05-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1088502A true CA1088502A (en) | 1980-10-28 |
Family
ID=19826112
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA277,315A Expired CA1088502A (en) | 1976-05-01 | 1977-04-29 | Process for the preparation of supported catalysts |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS52133895A (en) |
| BE (1) | BE854125A (en) |
| CA (1) | CA1088502A (en) |
| DE (1) | DE2719006A1 (en) |
| FR (1) | FR2349360A1 (en) |
| GB (1) | GB1574773A (en) |
| IT (1) | IT1086750B (en) |
| NL (1) | NL7604669A (en) |
| SU (1) | SU686601A3 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE364040T1 (en) | 2002-04-03 | 2007-06-15 | Du Pont | PRODUCTION OF DIHYDRONEPETALACTONE BY HYDROGENATION OF NEPETALACTONE |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB577008A (en) * | 1940-10-23 | 1946-05-01 | David Hallam Primrose Peel | Improvements in and relating to catalysts |
| GB1084354A (en) * | 1964-09-04 |
-
1976
- 1976-05-01 NL NL7604669A patent/NL7604669A/en not_active Application Discontinuation
-
1977
- 1977-04-26 GB GB1739577A patent/GB1574773A/en not_active Expired
- 1977-04-28 DE DE19772719006 patent/DE2719006A1/en not_active Withdrawn
- 1977-04-29 FR FR7713010A patent/FR2349360A1/en active Granted
- 1977-04-29 IT IT4921477A patent/IT1086750B/en active
- 1977-04-29 CA CA277,315A patent/CA1088502A/en not_active Expired
- 1977-04-29 BE BE177150A patent/BE854125A/en not_active IP Right Cessation
- 1977-04-29 SU SU772477059A patent/SU686601A3/en active
- 1977-05-02 JP JP5002977A patent/JPS52133895A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| FR2349360A1 (en) | 1977-11-25 |
| IT1086750B (en) | 1985-05-31 |
| DE2719006A1 (en) | 1977-11-17 |
| NL7604669A (en) | 1977-11-03 |
| JPS52133895A (en) | 1977-11-09 |
| SU686601A3 (en) | 1979-09-15 |
| FR2349360B1 (en) | 1984-02-24 |
| BE854125A (en) | 1977-10-31 |
| GB1574773A (en) | 1980-09-10 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |