CN104415752B - A kind of liquid phase selective hydrogenation of C 3 hydrocarbons catalyst and its preparation method and application - Google Patents

Abstract

The invention discloses a kind of liquid phase selective hydrogenation of C 3 hydrocarbons catalyst, nano-noble metal alloy active component is carried on carrier, described nano-noble metal alloy active component is nanoscale alloy particle, described nano-noble metal alloy active component is Pd X, metal X is the one in Ag, Au and Cu, and the mass ratio of alloy compositions is Pd:X=1:(0.2～5)；Described 0.2wt%～1.0wt% that nano-noble metal alloy content is carrier gross mass；Described nano-noble metal alloy active component is prepared through chemical reduction method in the microemulsion system that high molecular weight water soluble polymer is modified by bimetal complex, and is carried on carrier the catalyst obtaining the present invention.This catalyst is applied in propine and allene selective hydrogenation reaction have higher activity and selectivity thereof.

Description

A kind of liquid phase selective hydrogenation of C 3 hydrocarbons catalyst and its preparation method and application

Technical field

The present invention relates to a kind of liquid phase selective hydrogenation of C 3 hydrocarbons catalyst and its preparation method and application, specifically Ground is said and is related to a kind of loaded nano alloy selective hydrogenation catalyst and preparation method thereof, and this catalyst is used for splitting In hydrolysis products C3 fraction, propine and allene liquid phase selective hydrogenation generate the reaction of propylene.

Background technology

The liquid hydrocarbon feeds such as Petroleum are after steam cracking and separation, containing propylene in C3 fraction, and propane, And a small amount of propine and allene (being called for short MAPD), the content of MAPD is about 1%～5%(volume).Third In alkene polyreaction, MAPD can reduce the activity of polypropylene catalyst, affects the quality of polymerization-grade propylene product. Therefore MAPD must be removed from C3 fraction, current industrial use mostly catalysis selective hydrogenation with removing MAPD。

C 3 fraction selective hydrogenation catalyst uses precious metals pd supported catalyst.Cheung、Tin-Tack Peter et al. is in patent USP6, and 096,933 discloses a kind of alkynes, diene hydrogenation catalyst, and it is main Major catalyst Pd to be characterized as is distributed in carrier 150 micron thickness outer layer, and on carrier, Pd layer is the thinnest, from And improve the utilization rate of Pd, reduce green oil generating amount.Patent CN100512955C disclose a kind of alkynes and Diolefin hydrogenate catalyst and preparation method thereof, is coated on inert carrier outer surface by aluminum oxide coating layer, The main active component of catalyst and help active component to be distributed only on the aluminum oxide coating layer of catalyst surface, improves The hydrogenation efficiency of catalyst activity component.

The catalytic effect of main active component Pd can be improved by adding auxiliary agent.Auxiliary agent includes Ag, alkali metal etc., But according to adding compound in preparation process, the difference of carrier creates different effects to catalyst.Brown; Scott H.;Kimble;The selection hydrogenation that James B. et al. announces in patent USP5,698,752 is urged The composition of agent includes that Pd, alkali metal and F, inorganic carrier can be with COS of containing in resistance to material etc. containing S Impurity is poisoned, and removes good catalytic performance in the performance of alkynes hydrogenation process.Cheung、Tin-Tack Peter The unsaturated hydrocarbons that may be used for multiple high concentration Deng the selective hydrogenation catalyst announced at USP6,794,552 adds Hydrogen process, the composition of its catalyst mainly includes Pd, Ag, and it is raw material system that its carrier have employed metal aluminate Standby, its metal mainly has Zn, Ca.

Bimetal nano particles is different as the character of catalyst with monometallic nanoparticle as catalyst, Such as it is catalyzed the composition of the particles of active components of activity, catalyst, structure and component distribution relation to have very much There is researching value.Bimetallic composite metal catalyst is different from the characteristic of single-metal reforming catalyst, and this is due to former Interaction between son creates such as cooperative effect.Schaak etc. find with PVP stable under study for action AuPd₄Alloy nano particle is catalyst, when carrying out the synthetic reaction of hydrogen peroxide, finds AuPd₄Nanoparticle Compared with sub and pure Pd catalyst, selectivity is higher, and response speed is faster.

Do not precipitate although nanoparticle prepared by microemulsion method can maintain in inverse micelles within a certain period of time, But the prolongation of microemulsion standing time or be impregnated on carrier and destroy microemulsion environment, all can cause nanoparticle Son is grown up and precipitates, and affects catalyst and prepares.High molecular polymerization is added in micro-pond that microemulsion is formed Thing, can utilize its long carbon-chain structure and absorbability parcel, be wound around generated nanoparticle, reduce metal Particle is collision opportunity in fine droplet, prevents particle growth.When nano metal is supported on carrier surface, Under the extensional process of high molecular polymer, can be uniformly distributed, can't come off from carrier and assemble.

Microemulsion system is to be made up of aqueous phase, oil phase, surfactant and cosurfactant traditionally, body It is complex, controls and influence factor is more.The present invention develops the Emulsions without cosurfactant System, reduces the influence factor that microemulsion is formed, is beneficial to simplify catalyst preparation process.

Summary of the invention

The problem to be solved in the present invention is to provide a kind of liquid phase selective hydrogenation of C 3 hydrocarbons catalyst, this catalyst Activity in propine and allene hydrogenation reaction is higher, and selectivity is more preferable.

Concrete technical scheme is as follows:

An object of the present invention is to provide a kind of liquid phase selective hydrogenation of C 3 hydrocarbons catalyst, this catalyst bag Including carrier and the nano-noble metal alloy active component being carried on carrier, described nano-noble metal alloy is lived Property component is nanoscale alloy particle, and its mean diameter is 1-40nm；Described nano-noble metal alloy activity Component is prepared into through chemical reduction method in the microemulsion system that high molecular polymer is modified by bimetal complex Arrive, and be carried on carrier the catalyst obtaining the present invention.

Described nano-noble metal alloy active component is Pd-X, and metal X is the one in Ag, Au and Cu, The mass ratio of alloy compositions is Pd:X=1:(0.2～5)；Described nano-noble metal alloy content is that carrier is total 0.2wt%～1.0wt% of quality.

Described carrier is Al₂O₃、SiO₂、ZnO、TiO₂、V₂O₅、SnO₂In at least one.

Described nano-noble metal alloy active component preferred Pd-Ag alloy particle.

Described nano-noble metal alloy active component content is preferably 0.3wt%～0.6wt% of carrier gross mass, The mass ratio of its alloy compositions is preferably Pd:X=1:(0.25～2).

Described carrier is selected from Al₂O₃、SiO₂、ZnO、TiO₂、V₂O₅、SnO₂In one or both and two kinds Above mixture；More preferably carrier be shaped as spherical, profile of tooth, annular, tooth are spherical, granular, lamellar, Strip, Herba Trifolii Pratentis or Herba Galii Bungei.

Described high molecular weight water soluble polymer forms sediment selected from polyvinylpyrrolidone, polyacrylamide, carboxymethyl At least one in powder, acetic starch, hydroxymethyl cellulose, carboxymethyl cellulose, its content is noble metal 1～100 times of alloy active component gross mass.

Described nano-noble metal alloy active component is changed at high molecular weight water soluble polymer by bimetal complex The microemulsion system of property is prepared through chemical reduction method and comprises the following steps:

1. in water bath with thermostatic control, the aqueous phase being made up of bimetal complex aqueous solution and high molecular weight water soluble polymer The oil phase formed with ionic/nonionic type surfactant and organic solvent is mixed in proportion, and makes all Phase w/o type precious metal soluble salt microemulsion；Described bimetal complex is selected from the ammonia of noble metal One in complex, cyano complex, chloride ion complex；Described water soluble polymer polymerization Thing preferably is selected from least one in polyvinylpyrrolidone, polyacrylamide, carboxymethyl starch, excellent Select its content to be precious metal alloys active component gross mass 10-50 times；Described ionic/nonionic Type surfactant is in AOT, Brij30, Brij35, Brij56, Brij72, Brij78 At least one；Described oil phase is selected from C₄～C₁₀Cyclic alkane, linear paraffin, branched paraffin In a kind of or their mixture, preferably be selected from normal hexane, hexamethylene, normal octane and isobutyltrimethylmethane. One；Described ionic/nonionic type surfactant: oil phase: precious metal soluble salt is water-soluble Mass ratio=the 1:(0.1～5 of liquid): (0.1～4).

2. at 0～60 DEG C of addition reducing agent in above-mentioned w/o type precious metal soluble salt microemulsion, wherein: also Former dose is (1～10) with the mol ratio of slaine in aqueous phase: 1, described reducing agent be hydrazine hydrate, At least one in metal hydroboron, hydrogen, sodium hypophosphite, aromatic aldehyde, fatty aldehyde.

3. use the methods such as dipping, spraying, microemulsion 2. is impregnated, sprays on carrier, then carries out Be dried, roasting obtains described catalyst.

Second object of the present invention is to provide the preparation method of a kind of liquid phase selective hydrogenation of C 3 hydrocarbons catalyst. The preparation method of this catalyst comprises the following steps:

1) aqueous phase being made up of bimetal complex aqueous solution and high molecular weight water soluble polymer and ion/non-from The oil phase of subtype surfactant and organic solvent composition is mixed in proportion, and makes homogeneous water-in-oil type noble metal Complex microemulsion；

2) whipping process adds in noble metal complexes microemulsion reducing agent, make bimetallic network in microemulsion Compound aqueous solution is reduced to nano-noble metal alloy particle；

3) the nano-noble metal alloy particle prepared by microemulsion loads on carrier by the method for dipping, as Incipient impregnation, supersaturation dipping, spraying etc.；

4) to 3) gained catalyst is dried, roasting is prepared as described loaded noble metal catalyst.

The Pd-Ag Nanoalloy supported catalyst of the present invention is shown by transmission electron microscope (TEM) and test result The particle diameter of the nanoparticle of agent is 5nm, with single Pd and and the ultraviolet-visible spectrogram contrast of single Ag nanoparticle show Show prepared by the present invention for Pd-Ag alloy, refer to attached Fig. 1 and 2.The noble metal nano alloy of catalyst surface The particle diameter distribution of particle is shown by TEM test result, and Pd-Ag alloy nano particle is evenly distributed on catalyst Surface, and mean diameter is 8nm, refers to accompanying drawing 3.

The present invention compared with prior art has the advantage that

1) microemulsion system that high molecular weight water soluble polymer of the present invention is modified is prepared through chemical reduction method Nano-noble metal alloy active component, active component Pd-X(X represents the one in Ag, Au and Cu) in Nanoalloy particle shape is supported on carrier surface, and particle composition is uniform, and narrow diameter distribution is scattered, Being effectively improved active component utilization rate, catalyst is applied in propine and allene selective hydrogenation reaction to be had Higher activity and selectivity thereof.

2) catalysis that the present invention is prepared by the microemulsion system chemical reduction method that high molecular weight water soluble polymer is modified Agent, has that preparation condition is gentle, method is simple and the advantage such as easy operation.

Accompanying drawing explanation

Fig. 1 is the Pd-Ag Nanoalloy particle distribution of preparation

Fig. 2 is the alloy nano particle uv-vis spectra contrast with simple substance Pd and simple substance Ag nanoparticle of Pd-Ag

Fig. 3 is the distribution of catalyst surface Pd-Ag Nanoalloy particle

Detailed description of the invention

Catalyst that the present invention is explained further and preparation method thereof the most by way of example, but the present invention is not It is confined to these embodiments.

Embodiment 1

1. 40mgPd/ml [Pd(NH is pipetted₃)₄](NO₃)₂[the Ag(NH of solution 5ml, 100mgAg/ml₃)₄]NO₃Molten Liquid 6ml, weighs polyvinylpyrrolidone (PVP) 1500mg, and deionized water solution is diluted to 15g；

2. in the water bath with thermostatic control of 70 DEG C, by nonionic surfactant Brij3510g in 100ml volumetric flask, oil Phase isobutyltrimethylmethane. 10g, the magnetic agitation 4h time, then will be stirred for 30min in 1. adding 2., it is thus achieved that W/o type microemulsion；

3. add reducing agent hydrazine hydrate, be that 1:4 adds in microemulsion by the mol ratio of slaine in aqueous phase Yu reducing agent, Carry out reduction reaction, react 4 hours；

4. spherical SiO is weighed₂Carrier 100g, impregnates the above-mentioned microemulsion prepared；

5. the carrier 4. impregnating above-mentioned microemulsion is prepared as described catalyst through dry, roasting, is urged Agent GB-1, wherein Pd-Ag alloy content is the 0.8% of gross mass, and the mass ratio of Pd:Ag is 1:3.

Embodiment 2

1. 10mgPd/ml [(NH is pipetted₄)₂Pd]Cl₄The HAuCl of solution 5ml, 20mgAg/ml₄Solution 2.5ml, claims Taking polyacrylamide (PAM) 400mg, deionized water solution is diluted to 20g；

2. in the water bath with thermostatic control of 60 DEG C, by anion surfactant AOT5g, nonionic in 100ml volumetric flask Surfactant B rij726g, oil phase normal octane 15g, magnetic agitation 2h, then will 1. add 2. In be stirred for 1h, it is thus achieved that w/o type microemulsion；

3. add borane reducing agent sodium hydride, be that 1:8 adds by the mol ratio of slaine in aqueous phase Yu reducing agent, carry out also Former reaction, reacts 8 hours；

4. spherical TiO is weighed₂Carrier 100g, impregnates the above-mentioned microemulsion prepared；

5. the carrier 4. impregnating above-mentioned microemulsion is prepared as described catalyst through dry, roasting, is urged Agent GB-2, wherein Pd-Au alloy content is the 0.1% of gross mass, and the mass ratio of Pd:Au is 1:1.

Embodiment 3

1. 20mgPd/mlK is pipetted₂[Pd(CN)₄] solution 5ml, 300mgAg/mlKAgCN₂Aqueous solution 0.5ml, weigh PVP120mg, deionized water solution is diluted to 12g；

2. in the water bath with thermostatic control of 45 DEG C, by nonionic surfactant Brij3010g, oil phase in 100ml volumetric flask N-nonane 12g, magnetic agitation 4h, then will be stirred for 20min in 1. adding 2., it is thus achieved that w/o type microemulsion Liquid；

3. add reducing agent hydrazine hydrate, be that 1:8 adds in microemulsion by the mol ratio of slaine in aqueous phase Yu reducing agent, Carry out reduction reaction, react 1 hour；

4. column type Al is weighed₂O₃Carrier 100g, impregnates the above-mentioned microemulsion prepared；

5. being dried 12 hours at 110 DEG C by the carrier 4. impregnating above-mentioned microemulsion, high-temperature roasting is prepared as described urging Agent, the catalyst GB-3 obtained, wherein Pd-Ag alloy content is the 0.25% of gross mass, Pd:Ag's Mass ratio is 1:1.5.

Embodiment 4

1. 50mgPd/ml [Pd (NH is pipetted₃)₄]Cl₂[Cu (the NH of solution 10ml, 100mgCu/ml₃)₄]Cl₂Solution 1ml, Weighing hydroxymethyl cellulose 60mg, deionized water solution is diluted to 20g；

2. in the water bath with thermostatic control of 20 DEG C, by nonionic surfactant Brij565g in 100ml volumetric flask, cloudy from Sub-surface activating agent AOT8g, oil phase hexamethylene 18g, 2. 1. magnetic agitation 2h, in then adding It is stirred for 30min, it is thus achieved that w/o type microemulsion；

3., while stirring, it is passed through H₂, flow 100ml/min, carry out reduction reaction, react 4 hours；

4. trifolium-shaped Al is weighed₂O₃Carrier 100g, impregnates the above-mentioned microemulsion prepared；

5. being dried 8 hours at 105 DEG C by the carrier 4. impregnating above-mentioned microemulsion, high-temperature roasting is prepared as described urging Agent, the catalyst GB-4 obtained, wherein Pd-Cu alloy content is the 0.6% of gross mass, the matter of Pd:Cu Amount ratio is 1:0.2.

Comparative example

Weigh the Pd (NO of 100mg/ml₃)₂The AgNO of solution 6.5ml, 100mg/ml₃Solution 1.57ml, makes to spend Ionized water dilution 50ml, weighs 100gAl₂O₃Carrier adds the metal salt solution of dilution and stands 30min, is dried, Roasting, obtains catalyst WG-1.Wherein Pd content is 0.1wt%, and wherein Ag content is 0.1wt%.

The catalyst of above-described embodiment and comparative example is carried out C3 fraction propine and allene selective hydrogenation reaction, Reaction condition is as follows:

1ml catalyst is loaded in stainless steel tube reactor, after using nitrogen displacement, 180 DEG C of reductase 12s of hydrogen Hour, then unstripped gas being passed through in reactor, the composition (molar fraction) of reaction raw materials is: propane 4.99%, Propylene 92.3%, allene 1.09%, propine 1.12%, hydrogen and propine and the mol ratio of allene (MAPD) It is 1.6.Experiment air speed is 10000h^-1.By each catalyst reaction conversion ratio (Conversion) to (MAPD) With the computational methods of selectivity (Selectivity) it is:

$\mathrm{MAPD\; Conversion}=\frac{{\left(\mathrm{MAPD}\right)}_{\mathrm{in}}-{\left(\mathrm{MAPD}\right)}_{\mathrm{out}}}{{\left(\mathrm{MAPD}\right)}_{\mathrm{in}}}\×100\%$

$\mathrm{MAPD\; Selectivity}=\frac{{\left(C_2{H}_6\right)}_{\mathrm{out}}-{\left(C_2{H}_6\right)}_{\mathrm{in}}}{{\left(\mathrm{MAPD}\right)}_{\mathrm{in}}-{\left(\mathrm{MAPD}\right)}_{\mathrm{out}}}\×100\%$

Table 1 experimental result

As it can be seen from table 1 hydrogenation catalyst prepared by the microemulsion method of the present invention can reduce noble metal dosage, And compared with comparative example, in MAPD is hydrogenated to the reaction of propylene, the catalyst of the present invention has higher Conversion ratio and selectivity.

Claims (10)

1. a C 3 fraction selective hydrogenation catalyst, including carrier, it is characterised in that nano-noble metal alloy is lived Property component is carried on carrier, and described nano-noble metal alloy active component is nanoscale alloy particle, Its mean diameter is 1-40nm；Described nano-noble metal alloy active component is by bimetal complex The microemulsion system that high molecular weight water soluble polymer is modified prepares through chemical reduction method, and bears It is loaded on carrier and obtains described catalyst.

A kind of C 3 fraction selective hydrogenation catalyst the most according to claim 1, it is characterised in that described Nano-noble metal alloy active component is Pd-X, and metal X is the one in Ag, Au and Cu, alloy The mass ratio of component is Pd:X=1:(0.2～5)；Described nano-noble metal alloy active component contains Amount is 0.2wt%～1.0wt% of carrier gross mass.

A kind of C 3 fraction selective hydrogenation catalyst the most according to claim 2, it is characterised in that described Nano-noble metal alloy active component is Pd-Ag alloy particle.

A kind of C 3 fraction selective hydrogenation catalyst the most according to claim 2, it is characterised in that described Nano-noble metal alloy active component content is 0.3wt%～0.6wt% of carrier gross mass, its alloy group The mass ratio divided is Pd:X=1:(0.25～2).

A kind of C 3 fraction selective hydrogenation catalyst the most according to claim 1, it is characterised in that described Carrier is Al₂O₃、SiO₂、ZnO、TiO₂、V₂O₅、SnO₂In at least one；Outside described carrier Sight be shaped as spherical, profile of tooth, annular, tooth are spherical, granular, lamellar, strip, Herba Trifolii Pratentis or four leaves The carrier of grass-like；The specific surface area of described carrier is 1～200m²/g。

A kind of C 3 fraction selective hydrogenation catalyst the most according to claim 1, it is characterised in that described High molecular weight water soluble polymer is selected from polyvinylpyrrolidone, polyacrylamide, carboxymethyl starch, vinegar At least one in acid-starch, hydroxymethyl cellulose, carboxymethyl cellulose, its content is the expensive gold of nanometer Belong to 1～100 times of alloy active component gross mass.

A kind of C 3 fraction selective hydrogenation catalyst the most according to claim 1, it is characterised in that described in urge The preparation of agent comprises the following steps:

1. in water bath with thermostatic control, the aqueous phase being made up of bimetal complex aqueous solution and high molecular weight water soluble polymer with from The oil phase of son/nonionic surfactant and organic solvent composition is mixed in proportion, and makes homogeneous W/O Type noble metal complexes microemulsion；

2. 0～60 DEG C add reducing agent in above-mentioned w/o type noble metal complexes microemulsion, wherein: reducing agent with In aqueous phase, the mol ratio of slaine is (1～10): 1；

3. use dipping, spraying method, microemulsion 2. is impregnated, sprays on carrier, be then dried, Roasting obtains described catalyst.

A kind of C 3 fraction selective hydrogenation catalyst the most according to claim 7, it is characterised in that described is double Metal complex one in the ammino-complex of Pd and X, cyano complex, chloride ion complex, X is One in Ag, Au and Cu；Described high molecular weight water soluble polymer is selected from polyvinylpyrrolidone, gathers At least one in acrylamide, carboxymethyl starch, its content is precious metal alloys active component gross masses 10-50 times；Described ionic/nonionic type surfactant selected from AOT, Brij30, Brij35, At least one in Brij56, Brij72, Brij78；Described oil phase is selected from C₄～C₁₀Cyclic alkane, A kind of in linear paraffin, branched paraffin or their mixture；Described ionic/nonionic type surface Activating agent: oil phase: the mass ratio=1:(0.1～5 of bimetal complex aqueous solution): (0.1～4)； Described reducing agent is hydrazine hydrate, metal hydroboron, hydrogen, sodium hypophosphite, aromatic aldehyde, fat At least one in aldehyde.

9. the preparation method of a kind of C 3 fraction selective hydrogenation catalyst that one of claim 1-8 is described, its feature exists Include in the method:

1) aqueous phase being made up of bimetal complex aqueous solution and high molecular weight water soluble polymer and ionic/nonionic type The oil phase of surfactant and organic solvent composition is mixed in proportion, and makes homogeneous water-in-oil type noble metal network Compound microemulsion；

2) whipping process adds in noble metal complexes microemulsion reducing agent, make bimetal complex in microemulsion Aqueous solution is reduced to nano-noble metal alloy particle；

3) the nano-noble metal alloy particle prepared by microemulsion is loaded on carrier by the method for dipping；

4) to 3) gained catalyst is dried, roasting is prepared as described C 3 fraction selective hydrogenation catalyst.

10. a kind of C 3 fraction selective hydrogenation catalyst that one of claim 1-8 is described selects to add in C3 fraction Application in hydrogen.