阅读说明：本技术 一种用于甘油氧化催化剂的制备方法 (A kind of preparation method for glycerol oxidation catalyst ) 是由 刘熠斌 秦晗淞 闫昊 冯翔 金鑫 陈小博 杨朝合 于 2019-01-10 设计创作，主要内容包括：一种甘油催化氧化的催化剂的制备方法,包括：将固体碱分子筛与金属前躯体溶液混合、搅拌得到混合物1；在混合物1中加入硼氢化钠溶液进行还原反应；还原反应之后进行固液分离,分理后的固体1进行干燥即可得到甘油催化氧化的催化剂。本发明提供的Pt负载型固体碱介孔分子筛催化剂中载体结构非常规整,结晶度较高,使得碱土金属氧化物和Pt颗粒均匀的分散到催化剂表面,从而提高催化活性。本发明制备的Pt负载型固体碱介孔分子筛催化剂,在不破坏载体结构的前提下,不仅可以加入固体碱控制颗粒尺寸、调变分子筛碱性,而且利用介孔分子筛的限域效应,改善了催化剂的催化性能。(A kind of preparation method of the catalyst of glycerin catalytic oxidation, comprising: solid alkali zeolite is mixed with metallic precursor solution, stirs to get mixture 1；Sodium borohydride solution is added in mixture 1 and carries out reduction reaction；It is separated by solid-liquid separation after reduction reaction, the catalyst that glycerin catalytic oxidation can be obtained is dried in the solid 1 after sub-argument.Carrier structure is very regular in Pt load-type solid mesoporous molecular sieve catalyst provided by the invention, and crystallinity is higher, so that alkaline earth oxide and Pt is evengranular is distributed to catalyst surface, to improve catalytic activity.Pt load-type solid mesoporous molecular sieve catalyst prepared by the present invention, under the premise of not destroying carrier structure, solid base control particle size, modulation molecular sieve alkalinity can not only be added, but also using the confinement effect of mesopore molecular sieve, improve the catalytic performance of catalyst.)

1. a kind of preparation method of the catalyst of glycerin catalytic oxidation, comprising: by solid alkali zeolite and metallic precursor solution It mixes, stir to get mixture 1；Sodium borohydride solution is added in mixture 1 and carries out reduction reaction；It is carried out after reduction reaction It is separated by solid-liquid separation, the catalyst that glycerin catalytic oxidation can be obtained is dried in the solid 1 after sub-argument；

Wherein, solid alkali zeolite includes MgO/SBA series solid base mesopore molecular sieve, mesoporous point of MgO/MCM series solid base Son sieve or MgO/KIT series solid base mesopore molecular sieve；

It is preferred that solid alkali zeolite includes MgO/SBA series solid base mesopore molecular sieve, mesoporous point of MgO/KIT series solid base Son sieve；

It is further preferred that solid alkali zeolite includes MgO/SBA-15 solid base mesopore molecular sieve.

2. preparation method according to claim 1, which is characterized in that metal precursor includes chloroplatinic acid, potassium chloroplatinate, chlorine One or more kinds of mixing in sodium platinate；

It is preferred that metal precursor is chloroplatinic acid；

It is further preferred that the mass percent concentration of metallic precursor solution is 0.02%-0.05%；More preferably 0.024%-- 0.04%.

3. preparation method according to claim 2, which is characterized in that the sodium borohydride of addition and the molar ratio of chloroplatinic acid are 20:1-50:1 is preferably 30:1-40:1.

4. preparation method according to claim 1-3, which is characterized in that the load capacity of metal is controlled in 0.75- Between 1.2wt%；

It is preferred that the mass ratio of solid base SBA-15 molecular sieve and metal precursor is 1 when metallic precursor is six water chloroplatinic acid: 0.03-1:0.04, preferred 1:0.032-1:0.036.

5. preparation method according to claim 1-4, which is characterized in that starting that sodium borohydride solution is added dropwise When, the sodium borohydride solution of 1/2-2/3 is added with drop rate with 0.3mL/min-0.7mL/min.Preferably, start dropwise addition Preceding 1/2 sodium borohydride solution is added with 0.5mL/min-0.65mL/min.

6. preparation method according to claim 5, which is characterized in that remaining sodium borohydride solution rate of addition is with 1mL/ Min-3mL/min is added；Preferably, remaining sodium borohydride solution rate of addition is added with 1.5mL/min-2mL/min.

7. preparation method according to claim 1-5, which is characterized in that the concentration for sodium borohydride solution is 0.5%-1.2%, it is preferable that the mass percent concentration of sodium borohydride aqueous solution is in 0.7%-0.95%.

8. preparation method according to claim 1-7, which is characterized in that in solid alkali zeolite, alkali source and silicon The mass ratio of the material in source is 0.01:1-0.3:1, preferably 0.05:1-0.2:1；

It is preferred that Mg/Si 0.05-0.3, preferred Mg/Si are 0.05-0.2, more in MgO/SBA-15 solid alkali zeolite Preferred Mg/Si is 0.08-0.12.

9. preparation method according to claim 1-7, which is characterized in that the preparation method packet of solid alkali zeolite Include following steps:

(1) template P123 is added in acid solution, and stirs to dissolution and obtains solution 1；

(2) alkali source is added in solution 1 and is stirred, obtain solution 2；

(3) silicon source is added in solution 2, after stirring, crystallization, revolving, roasting, solid base SBA-15 molecular sieve is made.

10. preparation method according to claim 9, which is characterized in that the mass ratio of the material of template P123 and silicon source is 0.01:1-0.03:1, preferably 0.015:1-0.025:1,

The mass ratio of the material of alkali source and silicon source is 0.01:1-0.3:1, preferably 0.05:1-0.2:1.

Technical field

The application belongs to mesopore molecular sieve field, is related to the preparation method for glycerol oxidation catalyst, which is A kind of solid base mesopore molecular sieve, and in particular to preparation method of Pt load-type solid mesoporous molecular sieve catalyst.

Background technique

Alcohols material is industrially important raw material or intermediate as a major class organic substance.It is for example cheap Glycerol stocks can by oxidation reaction prepare high added value glycerol production acid, glycerol as prepare in biodiesel process one Kind of important by-products, containing there are three functional groups in molecule, chemical property is active, and it is anti-can to participate in the chemistry such as oxidation, polymerization, condensation Should simultaneously its aoxidize purpose product glyceric acid as one kind important drug and medicine intermediate and there is extensive exploitation value Value., therefore, it is concerned by the reaction process that glycerol oxidation prepares glyceric acid.It has been reported that display, adds in glycerol oxidation reaction The product that entering liquid base sodium hydroxide can be improved the conversion ratio of glycerol and the yield of glyceric acid, but obtain is sodium glycerinate, And non-final product glyceric acid, increase the difficulty of Analyze & separate.

Chinese patent application discloses No. 101279911A and describes the method that glycerin catalytic oxidation prepares glyceric acid, uses Carbon nanotube loaded metallic catalyst after functionalization.Chinese patent application discloses No. 105688935A and describes alcohols catalysis Catalyst Pt/Cu-Ni of oxidation.

In order to find more, better alcohols catalyst for catalytic oxidation, especially catalysis oxidation glycerol prepares glyceric acid, widens The application of glycerol oxidation, the present invention is specifically proposed.

Summary of the invention

One of the application is designed to provide a kind of preparation method of the catalyst of glycerin catalytic oxidation, this method preparation Obtained catalyst improve conversion ratio of glycerol in the presence of no akaline liquid.

Further object provides the preparation side that a kind of in-situ synthesis prepares solid base mesopore molecular sieve carrier Method, this method can not only retain the regular structure of mesoporous supports, while it is uniform that mesopore molecular sieve carrier surface is had Basic site distribution.

Further object is to provide a kind of preparation side of Pt load-type solid mesoporous molecular sieve catalyst Method, in this method, the introducing in mesopore molecular sieve surface alkalinty site can make the dispersion of Pt particle more uniform, simultaneously because The confinement in mesopore molecular sieve duct acts on so that unique " strip " is presented in the pattern of Pt nano particle.

To achieve the above object, the application adopts the following technical scheme that

A kind of preparation method of the catalyst of glycerin catalytic oxidation, comprising: solid alkali zeolite is molten with metallic precursor Liquid mixing stirs to get mixture 1；Sodium borohydride solution is added in mixture 1 and carries out reduction reaction；Reduction reaction it is laggard Row is separated by solid-liquid separation, and the catalyst that glycerin catalytic oxidation can be obtained is dried in the solid 1 after sub-argument.

Wherein, solid alkali zeolite includes MgO/SBA series solid base mesopore molecular sieve, MgO/MCM series solid base Jie Porous molecular sieve, MgO/KIT series solid base mesopore molecular sieve etc..It is preferred that solid alkali zeolite includes MgO/SBA series solid base Mesopore molecular sieve, MgO/KIT series solid base mesopore molecular sieve.It is further preferred that solid alkali zeolite includes MgO/SBA-15 solid Alkali mesopore molecular sieve.

The metal of the catalyst load of the application includes Pt.

The catalyst of the preparation of the application is particularly suitable for glycerin catalytic oxidation and prepares in the reaction of glyceric acid, improves sweet The conversion ratio of oil and the selectivity of glyceric acid.

The Pt load type solid body base catalyst of the application preparation has difunctional site: basic site and metallic site, In The surface of neutral mesopore molecular sieve (for example: SBA-15) forms many active sites.Especially SBA-15 mesopore molecular sieve, by Make the platinum in load that unique strip pattern be presented in the confinement effect of the mesopore orbit of SBA-15, be conducive to reactant and The contact of product and mass transfer enhance the application of catalyst in the oxidation reaction.

Detailed description of the invention

Fig. 1 solid alkali zeolite MgO/SBA-15 high power transmission electron microscope picture

Fig. 2 Pt supported solid molecular sieve catalyst (Mg/Si=0.1)

The a certain embodiment of Fig. 3 prepares the TEM figure of Pt supported solid molecular sieve catalyst

Fig. 4 certain embodiments prepare the grain size distribution and TEM figure of Pt supported solid molecular sieve catalyst

The catalyst reaction performance figure of Fig. 5 certain embodiments preparation

The XRD diagram of Fig. 6 solid alkali zeolite carrier

Specific embodiment

In order to better understand present invention content, below in conjunction with the application specific embodiment, embodiment with And attached drawing, the technical solution of the application is clearly and completely described, following implementation is used to illustrate the application, but not For limiting scope of the present application.

In the following examples, the experimental methods for specific conditions are not specified, usually according to normal condition or according to institute, manufacturer It is recommended that condition.Unless otherwise stated, otherwise all percentage, ratio, ratio or number be by weight.

Magnesium silicon ratio is the molar ratio of element in the application.

Term " mesoporous ", typically refers to aperture in 2-50nm.

Unless otherwise defined, it anticipates known to all professional and scientific terms as used herein and one skilled in the art Justice is identical.In addition, any method similar to or equal to what is recorded and material all can be applied in the application method.Wen Zhong The preferred implement methods and materials are for illustrative purposes only.Term " TOF " is usually used in measuring the rate of catalyst reaction, The turn over number of single active site in unit time, the catalytic activity that catalyst is measured using TOF value is had become to be catalyzed now The important index in one, field

In certain embodiments in this application, a kind of preparation side of Pt load-type solid mesoporous molecular sieve catalyst Method, comprising:

Solid base SBA-15 molecular sieve is mixed with Pt metal front liquid solution, is stirred to mixture 1；In mixture 1 Sodium borohydride solution is added and carries out reduction reaction；It is separated by solid-liquid separation after reduction reaction, isolated solid 1 is dried The catalyst of glycerin catalytic oxidation can be obtained.

Wherein, Pt metal precursor selects chloroplatinic acid, potassium chloroplatinate, one or more kinds of mixed in platinic sodium chloride It closes.It is preferred, and Pt metal precursor is chloroplatinic acid.

The solid base mesopore molecular sieve used in the application can be selected using magnesium salts as alkali source, it is preferable that solid base is mesoporous Molecular sieve is using magnesium salts as MgO/SBA-15 molecular sieve prepared by alkali source.

In some embodiments, Pt metal front liquid solution is six water chloroplatinic acid aqueous solutions, six water chloroplatinic acid aqueous solutions Mass percent concentration be 0.02%-0.05%；Preferably 0.024%--0.04%.

In some embodiments, the molar ratio of the sodium borohydride of addition and six water chloroplatinic acids is 20:1-50:1, preferably For 30:1-40:1.

Pt is loaded in MgO/SBA-15 solid alkali zeolite, and SBA-15 mesopore molecular sieve is high-sequential plane hexagonal phase, With bidimensional hexagonal hole road, aperture size is between 4.6~30nm, and silica pore wall thickness is between 3.1~6.0nm, In SBA-15 molecular sieve is almost without the neutral material of any acid-base property.In this application, by using introducing basic site SBA-15 molecular sieve, then supporting Pt metal, the Pt metal concerted catalysis that can be played and load due to the introducing of basic site Effect greatly improves turning for glycerol so that its reactivity significant increase, comes particularly with selective glycerol oxidation reaction Rate.

In this application, using chemical reduction method on solid alkali zeolite supporting Pt metal, reducing agent is using boron Sodium hydride, for the metal front liquid solution being added in the whipping process with carrier, metal precursor molecules diffuse to mesoporous hole In road, Pt nano particle and confinement can rapidly be restored into mesopore orbit using sodium borohydride.

In some embodiments, when starting that sodium borohydride solution is added dropwise, the sodium borohydride solution of 1/2-2/3 is to be added dropwise Rate is added with 0.3mL/min-0.7mL/min.Preferably, preceding 1/2 sodium borohydride solution for starting to be added dropwise is with 0.5mL/min- 0.65mL/min is added.

In some embodiments, remaining sodium borohydride solution rate of addition is added with 1mL/min-3mL/min；It is preferred that , remaining sodium borohydride solution rate of addition is added with 1.5mL/min-2mL/min.Remaining sodium borohydride solution can also be with It is added dropwise lower than the speed, prepares the overall time-consuming of catalyst to comprehensively consider, preferably above-mentioned speed is added dropwise.

In some embodiments, the mass percent concentration of sodium borohydride aqueous solution is in 0.5%-1.2%, it is preferable that boron The mass percent concentration of sodium hydride aqueous solution is in 0.7%-0.95%.

Metal precursor molecules are restored using sodium borohydride in metal recovery process, by Metal Supported mesoporous On molecular sieve.Wherein, in order to enable Pt metal shows better catalytic performance, sodium borohydride more evenly in mesopore molecular sieve The preferred 0.5%-1.2% of the concentration of solution, or the rate of addition of sodium borohydride solution is controlled in 0.3mL/min-0.7mL/ min.When the excessive catalyst effect of metal partial size can be deteriorated, when sodium borohydride reduction excessive velocities will lead to Pt metal point Aggregation is in sub- sieve pore road to cause mesoporous blocking.The reduction rate of sodium borohydride by metal precursor concentration and hydroboration The rate of addition of sodium is determined.

Control Pt metal precursor aqueous solution mass percent concentration is 0.02%-0.05% in the implementation of certain schemes； Preferably 0.024%--0.04% prevents metal from reuniting enough.

In the application, sodium borohydride solution is added dropwise using two sections of performance rate methods and preferably controls partial size, on the one hand can prevent The aggregation of Pt metal, on the other hand can be improved production efficiency.

In some embodiments, the load capacity of Pt metal controls between 0.75-1.2wt%.In the range load capacity, It is fine to glycerol oxidation catalysis reaction effect.Preferred control load capacity is best in 1wt% or so effect.

For, when metallic precursor is six water chloroplatinic acid, the mass ratio of solid base SBA-15 molecular sieve and metal precursor For 1:0.03-1:0.04, preferred 1:0.032-1:0.036.

The solid 1 obtained after to reduction in the drying process, controls drying temperature at 25 DEG C -80 DEG C；Preferred solid 1 It is dried in vacuo, drying temperature is at 25 DEG C -50 DEG C.

The dry time of solid 1, moisture content reached particular requirement determines according to actual conditions.Preferably, it does The dry time is in 9-15h, more preferable 10-12h.

Drying temperature must not exceed 80 DEG C, to prevent Pt metal from aoxidizing.

The preparation method of the specifically carrier solid alkali molecular sieve of the application use includes the following steps:

(1) template P123 is added in acid solution, and stirs to dissolution and obtains solution 1；

(2) alkali source is added in solution 1 and is stirred, obtain solution 2；

(3) silicon source is added in solution 2, after stirring, crystallization, revolving, roasting, solid base SBA-15 molecule is made Sieve.

Acid solution in the application includes hydrochloric acid and/or sulfuric acid, preferably hydrochloric acid, and controls concentration of hydrochloric acid in 1.4mol/L- 2mol/L more preferably controls concentration of hydrochloric acid 1.6mol/L.

Alkali source includes magnesium salts as alkali source in the application.

In some embodiments, the alkali source magnesium salts in the application include one of magnesium nitrate, magnesium chloride, magnesium acetate or The two or more mixture of person, preferably magnesium acetate.

In silicon source silica solution, waterglass, solid silicone, diatomite, silicate and tetraethyl orthosilicate in the application One or more kinds of mixtures, preferably tetraethyl orthosilicate.

Template P123 is the preparation common template of SBA-15, entitled polyethylene oxide-polypropylene oxide-polycyclic Oxidative ethane triblock copolymer, molecular weight is 5800.

The mass ratio of the material of template and silicon source is 0.01:1-0.03:1, preferably 0.015:1-0.025:1.

In some embodiments, it is more than hour need to stir 6 for the template in step (1), preferably 8 hours, it is ensured that Template has been completely dissolved in acid solution.

In some embodiments, the silicon source in step (3) can be instilled or be quickly poured into dropwise, excellent in the application Choosing is quickly poured into.

In this application, the mass ratio of the material of alkali source and silicon source is 0.01:1-0.3:1, preferably 0.05:1-0.2:1.

The alkali content of basic site plays a crucial role Metal Supported and redox reaction, wherein at this In application, Mg/Si 0.05-0.3, preferred Mg/Si are 0.05-0.2, and more preferably Mg/Si is 0.08-0.12.

In the application method, when Mg/Si is 0.05-0.3, Metal Supported is more uniformly dispersed in mesopore molecular sieve On.Mg/Si is that its Pt of the ratio of 0.08-0.12 loads that partial size is minimum, distribution the most uniformly, glycerol oxidation effectiveness is best.

In some embodiments, the condition in crystallization process includes: 80 DEG C -140 DEG C of crystallization temperature, crystallization time 12- 60h；Preferably, 80~120 DEG C of crystallization temperature, crystallization time 12-48h；It is furthermore preferred that 100 DEG C of crystallization temperature, crystallization time 24h。

The application method passes through the solid base SBA-15 molecular sieve to mixed liquor progress crystallization China preparation, internal gutter row Column are the most regular, and duct is suitble to subsequent load operation in 8nm or so.

In some embodiments, post-processing includes revolving, is dried, roasting.

In some embodiments, the temperature in step (3) in whipping process is at 35-45 DEG C, and preferably 40 DEG C.

In some embodiments, on the one hand it can prevent alkali source be added from losing using the method for low temperature revolving, especially It is magnesium salts for alkali source, and low temperature revolving can be such that basic site MgO is uniformly distributed.The temperature wherein rotated is at 50 DEG C -60 DEG C.

Wherein 550 DEG C of roasting effects of roasting process are best, can thoroughly burn up template.

The present invention also provides kind of an application of the Pt load-type solid mesoporous molecular sieve catalyst in glycerol oxidation reaction.

Pt supported solid mesoporous molecular sieve catalyst, which is applied in glycerol oxidation reaction, prepares glyceric acid, wherein now such as Glycerol oxidation efficiency is improved frequently with by the way that liquid base NaOH is added in modern glycerol oxidation reaction, but the addition meeting of liquid base Lead to react purpose product and generates that salt is unfavorable for the purifying in later period and separation does not meet the thought of Green Chemistry, and the application uses In-situ synthesis prepares solid base carrier, and especially MgO provides basic site, is loaded using the carrying method of sodium borohydride reduction Pt metal, for Pt nano metal as metal active constituent, the synergistic effect of basic site and metallic site constructs this Shen jointly Please in bifunctional catalyst to improving the oxidation efficiency of glycerol and the yield of purpose product glyceric acid.

Compared with prior art, the application has the following beneficial effects:

Solid base mesopore molecular sieve provided herein, especially MgO/SBA-15 molecular sieve carrier, mesopore orbit point Cloth is very regular, and surface alkalinty site is evenly distributed there is no agglomeration occurs, and there is no blocked up mesopore orbit by MgO Plug, MgO is evenly distributed in the surface and duct of mesoporous SBA-15 molecular sieve, due to the heat of the SBA-15 molecular sieve in the application Stabilization is good enough, so the basic site adulterated in situ does not destroy the meso-hole structure of molecular sieve.

The application is loaded to Pt nano metal in solid alkali zeolite using the method for sodium borohydride reduction, suitable alkali Property site facilitate Pt nano metal load and can make load Pt metal partial size it is smaller, be distributed it is more uniform, and by Under the mesoporous confinement effect of solid base SBA-15 molecular sieve, unique strip shape is presented in the pattern of Pt metal.Exactly Unique strip pattern in this hole wall can make glycerol molecule diffuse in duct under the effect for not influencing mass transfer just Make to carry out in its conversion process towards glyceric acid in absorption contact active site.

The Pt load-type solid mesopore molecular sieve bifunctional catalyst that the application is constructed, suitable basic site are conducive to The load and dispersion of metallic site, the addition of basic site improve the active force of metal and carrier, it is therefore prevented that in reaction process The leaching of Pt metal improves the stability of catalyst.

The Pt load-type solid mesoporous molecular sieve catalyst that the application is constructed has pole to have on glycerol oxidation field The application space of prospect.It does not need additional liquid base when using the catalyst of the application to be added, and its reactivity is Reach the reactivity under liquid base is added.The catalyst of the application can make glycerol conversion ratio and glyceric acid selectivity it is equal Up to 60% or more, TOF value up to 1500h^-1More than.

Below with reference to specific example to the further details of explanation of present invention content, but do not limit institute of the present invention Scope of authority to be protected.