CN104383963A

CN104383963A - Ligand modified load type acetylene hydrogenation Pd catalyst and preparation method of catalyst

Info

Publication number: CN104383963A
Application number: CN201410666452.3A
Authority: CN
Inventors: 王康军; 台宝泉; 李东楠; 张雅静; 丁茯; 吴静
Original assignee: Shenyang University of Chemical Technology
Current assignee: Shenyang University of Chemical Technology
Priority date: 2014-11-20
Filing date: 2014-11-20
Publication date: 2015-03-04
Anticipated expiration: 2034-11-20
Also published as: CN104383963B

Abstract

The invention discloses a ligand modified load type acetylene hydrogenation Pd catalyst and a preparation method of the catalyst, and relates to a catalyst and a preparation method of the catalyst. The Pd is used as an active component; the percentage by weight of Pd is 1%-3%; the surface of a carrier, namely silicon dioxide, is grafted with an organic group containing N and S; alkyl sulfhydryl is used as a ligand; tetrabutylammonium borohydride is used as a reducing agent; the adopted palladium salt is PdCl2 or palladium nitrate; a methylbenzene solution is used as a solvent. The preparation method of the catalyst comprises the following steps: dissolving the palladium salt in the methylbenzene solution, adding the alkyl sulfhydryl ligand, carrying out ultrasonic oscillation until a colored solution is clarified, then adding tetrabutylammonium borohydride, finally adding organic modification silicon dioxide powder to obtain the catalyst. The alkyl sulfhydryl ligand is introduced into the catalyst, so that the performance of a Pd loaded catalyst can be effectively regulated; the conversation rate of acetylene is 100%, the selectivity of acetylene is greater than 90% and the performance of acetylene is stable under the conditions of low reaction temperature and high hydrogen-acetylene ratio.

Description

A kind of ligand modified support type acetylene hydrogenation Pd Catalysts and its preparation method

Technical field

The present invention relates to a kind of Catalysts and its preparation method, particularly relate to a kind of ligand modified support type acetylene hydrogenation Pd Catalysts and its preparation method.

Background technology

In catalytic reaction process, the committed step that catalytic action is relevant, desorption etc. as the absorption of reactant, diffusion and product all relates to the electron transmission between catalyst surface and reaction species, and the distribution of the valence electron of catalyst surface and the catalytic performance of structure on catalyst have very important impact.Therefore, how effectively the characteristic of regulating catalyst surface electronic, particularly valence electron is the key core problem realizing catalyst initiative.Loaded catalyst is usually by changing the character of carrier and adding the performance that auxiliary agent etc. improves catalyst.Park etc. on palladium/aluminium oxide catalyst, add alkali metal potassium or alkaline earth metals calcium, magnesium etc. modify alumina support, improve ethylene selectivity, decrease green oil generating amount, extend the cycle of operation.Chinayon introduces by sol-gel process the acidity that Zn reduces carrier in alumina support, makes the selective raising of ethene.The comparative studies such as Huang Na ⁺exchange the palladium catalyst of beta-zeolite molecular sieve load and traditional Pd/ γ-Al ₂o ₃the acetylene hydrogenation performance of catalyst.Ihm etc. have studied Pd/TiO ₂the C of catalyst ₂fraction selec-tive hydrogenation catalytic performance, finds that titania support also can be interacted with metal by hydrogen reduction strongly under certain condition, Pd/TiO ₂catalyst reduces at 250 DEG C, and ethylene selectivity is the highest, about reaches 91 %, and its catalytic performance is obviously better than Pd/Al ₂o ₃catalyst.Chu etc. find that in titania support, introduce MgO significantly improves the ethylene selectivity of Pd catalyst and the stability of catalyst.Panpranot etc. have studied the acetylene hydrogenation performance of the palladium catalyst of micron and nano-crystalline titanium dioxide load.The present invention adopts part to regulate and control Pt-supported catalyst acetylene hydrogenation performance first, realizes the result of 100% conversion of alkyne and more than 90% ethylene selectivity.

Summary of the invention

The object of the present invention is to provide a kind of ligand modified support type acetylene hydrogenation Pd Catalysts and its preparation method, the method can Effective Regulation Pt-supported catalyst performance by introducing alkyl hydrosulfide part, at lower temperature reaction temperature and high hydrogen alkynes than under condition, conversion of alkyne is 100%, ethylene selectivity more than 90%, and stable performance.

The object of the invention is to be achieved through the following technical solutions:

A kind of ligand modified support type acetylene hydrogenation Pd catalyst, described Pd is active component, and its mass percentage is 1%-3%; Its surface grafting of carrier silicas contains the organic group of N, S; Its alkyl hydrosulfide is as part, and tetrabutyl ammonium borohydride is as reducing agent; The palladium salt adopted is PdCl2 or palladium nitrate, and solvent is toluene solution, and every 0.01g PdCl2 needs to be dissolved in 5-10 ml toluene solution; Part and palladium mol ratio are 1:1-3:1; Pd load capacity is 1%-3%.

A kind of ligand modified support type acetylene hydrogenation Pd method for preparing catalyst; described method comprises and is dissolved in toluene solution by palladium salt; add alkyl hydrosulfide part; ultrasonic oscillation, in clarification colored solutions, then adds tetrabutyl ammonium borohydride, finally adds organically-modified SiO 2 powder; constantly be stirred to solvent to evaporate; filtration washing, vacuum drying, obtains ligand protection load type palladium nanocatalyst.

Advantage of the present invention and effect are:

This catalyst can Effective Regulation Pt-supported catalyst performance by introducing alkyl hydrosulfide part, and at lower temperature reaction temperature and high hydrogen alkynes than under condition, conversion of alkyne is 100%, ethylene selectivity more than 90%, and stable performance.

Detailed description of the invention

Below in conjunction with embodiment, the invention will be further described.

Palladium bichloride is dissolved in toluene solution, add the mercaptan of different carbon chain lengths, ultrasonic oscillation is in clarification colored solutions, then tetrabutyl ammonium borohydride is added, finally add SiO 2 powder, 40-60 DEG C of condition is constantly stirred to solvent and evaporates, filtration washing, 60-80 DEG C of vacuum drying, obtains ligand protection load type palladium nanocatalyst; Wherein alkyl hydrosulfide is as part, and tetrabutyl ammonium borohydride is as reducing agent; Wherein Pd load capacity is 1%-3%, and part and palladium mol ratio are 1:1-3:1.

Embodiment 1: the palladium bichloride of 0.01g is dissolved in 5ml toluene solution; add 0.023g n-dodecyl mereaptan; ultrasonic oscillation is to clarification; then add 0.0533g tetrabutyl ammonium borohydride, finally add the SiO 2 powder of the organic S modification of 1g, under 40 DEG C of conditions, be constantly stirred to solvent evaporate; filtration washing; 60 DEG C of vacuum drying 12h, grinding compressing tablet, obtains ligand protection load type palladium nanocatalyst.

Embodiment 2: the palladium bichloride of 0.02g is dissolved in 10ml toluene solution; add 0.046g n-dodecyl mereaptan; ultrasonic oscillation is to clarification; then add 0.1066g tetrabutyl ammonium borohydride, finally add the SiO 2 powder that 1g has the modification of S machine, under 40 DEG C of conditions, be constantly stirred to solvent evaporate; filtration washing; 60 DEG C of vacuum drying 12h, grinding compressing tablet, obtains ligand protection load type palladium nanocatalyst.

Embodiment 3: the palladium bichloride of 0.03g is dissolved in 15ml toluene solution; add 0.069g n-dodecyl mereaptan; ultrasonic oscillation is to clarification; then add 0.1599g tetrabutyl ammonium borohydride, finally add the SiO 2 powder that 1g has the modification of S machine, under 40 DEG C of conditions, be constantly stirred to solvent evaporate; filtration washing; 60 DEG C of vacuum drying 12h, grinding compressing tablet, obtains ligand protection load type palladium nanocatalyst.

Embodiment 4: the palladium bichloride of 0.01g is dissolved in 5ml toluene solution; add 0.023g n-dodecyl mereaptan; ultrasonic oscillation is to clarification; then add 0.533g tetrabutyl ammonium borohydride, finally add the SiO 2 powder of 1g Organic N modification, under 40 DEG C of conditions, be constantly stirred to solvent evaporate; filtration washing; 60 DEG C of vacuum drying 12h, grinding compressing tablet, obtains ligand protection load type palladium nanocatalyst.

Embodiment 5: be dissolved in 10ml toluene solution by the palladium bichloride of 0.02g, adds 0.046g C ₆h ₁₃sH; ultrasonic oscillation is to clarification; then 0.1066g tetrabutyl ammonium borohydride is added; finally add the SiO 2 powder of 1g Organic N modification; under 40 DEG C of conditions, be constantly stirred to solvent evaporate, filtration washing, 60 DEG C of vacuum drying 12h; grinding compressing tablet, obtains ligand protection load type palladium nanocatalyst.

Embodiment 6: be dissolved in 15ml toluene solution by the palladium bichloride of 0.03g, adds 0.069g C ₈h ₁₇sH; ultrasonic oscillation is to clarification; then 0.1599g tetrabutyl ammonium borohydride is added; finally add the SiO 2 powder of 1g Organic N modification; under 40 DEG C of conditions, be constantly stirred to solvent evaporate, filtration washing, 60 DEG C of vacuum drying 12h; grinding compressing tablet, obtains ligand protection load type palladium nanocatalyst.

By the catalyst compressing tablet of preparation, pulverize obtained 40-60 object particle.Getting 0.1g beaded catalyst loading internal diameter is in the glass reaction tube of 4mm.Pass into the H that flow is 24ml/min ₂, under 120 DEG C of conditions, reduce 90min.Pass into the H that flow is 24ml/min more simultaneously ₂be the C of 30ml/min with flow ₂h ₂gaseous mixture, react under condition of different temperatures, product is analyzed by gas-chromatography.

Experimental result is as shown in table 1.

Table 1 reaction result

Example	Temperature (DEG C) when acetylene transforms completely	Conversion of alkyne (%)	Ethylene selectivity (%)
				1	120	100	94
2	90	100	92
				3	80	100	94
4	120	100	86
				5	70	100	78
6	40	100	82

Claims

1. a ligand modified support type acetylene hydrogenation Pd catalyst, it is characterized in that, described Pd is active component, and its mass percentage is 1%-3%; Its surface grafting of carrier silicas contains the organic group of N, S; Its alkyl hydrosulfide is as part, and tetrabutyl ammonium borohydride is as reducing agent; The palladium salt adopted is PdCl ₂or palladium nitrate, solvent is toluene solution, every 0.01g PdCl ₂need to be dissolved in 5-10 ml toluene solution; Part and palladium mol ratio are 1:1-3:1; Pd load capacity is 1%-3%.

2. a ligand modified support type acetylene hydrogenation Pd method for preparing catalyst; it is characterized in that; described method comprises and is dissolved in toluene solution by palladium salt, adds alkyl hydrosulfide part, and ultrasonic oscillation is in clarification colored solutions; then tetrabutyl ammonium borohydride is added; finally add organically-modified SiO 2 powder, be constantly stirred to solvent and evaporate, filtration washing; vacuum drying, obtains ligand protection load type palladium nanocatalyst.