KR20140075214A - Nano-sized Mesoporous Carbon supported Catalyst for Aqueous Phase Reforming reaction and preparing method thereof - Google Patents

Abstract

The present invention relates to a catalyst for an aqueous phase reforming reaction having a nano-sized mesoporous carbon carrier, a method for producing the same, and a method for producing hydrogen from oxygen-containing hydrocarbon through the aqueous phase reforming reaction using the same. When the catalyst of the present invention is used for the aqueous phase reforming reaction for producing hydrogen from oxygen-containing hydrocarbon, the catalyst has a larger surface area than an existing micro-sized mesoporous carbon carrier so that the degree of dispersion of active metals is increased and the structure of mesopores is developed. Accordingly, the speed of transferring and diffusing material becomes rapid so that the transfer rate, production rate, and production speed of hydrogen gas can be improved.

Description

TECHNICAL FIELD The present invention relates to a nano-sized mesoporous carbon support catalyst for an aqueous phase reforming reaction and a method for preparing the same.

The present invention relates to an aqueous phase reforming catalyst having a nano-sized mesoporous carbon support, a process for producing the same, and a process for producing hydrogen through an aquatic reforming reaction using oxygen hydrocarbons.

The water reforming reaction refers to a technique for selectively producing hydrogen from oxygen-containing hydrocarbons in various kinds of aqueous solutions derived from biomass such as glucose, methanol, glycerol, ethylene glycol, sorbitol, sugar alcohol and the like. As shown in the following reaction formula, the reforming reaction and the water-gas shift (WGS) reaction in one reactor are carried out at a low temperature of less than 300 ° C. And the concentration of carbon monoxide (CO) obtained from the product is as low as 100 ppm or less.

C _n H _{2n + 2} + _n H ₂ O ↔ n CO + (2n + 1) H _{2 ----} reforming reaction

CO + H ₂ O ↔ CO ₂ + H _{2 -------------------} Water gas conversion

Therefore, such a water reforming reaction requires a reforming reaction at a high temperature of steam reforming reaction, which is a typical known hydrogen production method, and a separate methanation reaction step for reducing carbon monoxide generated from the reforming reaction to 100 ppm or less There is an advantage that it is not necessary. That is, the water reforming reaction not only causes almost no byproducts such as methane having toxicity, but also has a higher hydrogen production rate and selectivity than the steam reforming reaction.

Studies on such an aqueous reforming reaction have been made variously for the purpose of producing hydrogen from an oxygenated carbohydrate compound in aqueous solution, which is induced by hydrolysis of biomass, which is a renewable energy resource.

The reaction mechanism of the aqueous reforming reaction can be classified into three types of reactions, namely, CC cleavage, CO cleavage, water gas conversion, dehydrogenation reaction, methanation reaction, Fischer-Tropsch reaction , Etc., are converted into carbon dioxide and hydrocarbons including hydrogen.

These various chemical reactions are very closely related to the active metal components, the feedstock fed, the reaction conditions, and the catalyst support. Therefore, in order to increase the selectivity of hydrogen from deoxygenated hydrocarbons by the water reforming reaction, it is necessary to maximize the carbon-carbon cleavage reaction on the surface of the catalytic metal, which is the active material, while the carbon- It is necessary to select suitable catalysts to control the reaction and to control the reaction parameters.

Therefore, many studies have been conducted to control the hydrogen production rate and selectivity in such a water reforming reaction (MFL Johnson, J. Catal. 123 (1990) 245-259; JW Shabaker, GW Huber, RR Davda, RD G. Wen, Y. Xu, H. Ma, K. Ketchie, EP Maris, RJ Davis, Chem.Mater. 19 (2007) 3406-3411, Z. Xu, Z. Tian, Int. J. Hydrogen Energy. 33 (2008) 6657-6666). In particular, since the catalyst carrier greatly affects the afore-mentioned water reforming reaction, much research has been conducted on the catalyst support. Conventional Al ₂ O ₃ , ZrO ₂ , SiO ₂ , CeO ₂ , ZnO, TiO ₂ Or the like is used as a support, pores are collapsed by sintering under a high-temperature and high-pressure aqueous solution, which is a reaction condition, and the specific surface area of the support is reduced in a wide range of meta stable phase There is a problem that the phase reforming reaction is very unstable because the phase transition occurs.

In order to solve such problems, a porous support having excellent hydrothermal stability is required. The porous support is required to have a large surface area capable of promoting the reaction in the liquid phase, a proper pore volume, mechanical / Carbon-based support materials have attracted attention and many studies have been conducted on them.

In the past, Patent Documents 1 and 2 disclose an example in which a catalyst in which vulcan carbon is used as a support and a VIIB-group transition metal and a VIII-group transition metal are impregnated into an aqueous hydrocarbon reforming reaction.

In addition, an example in which a catalyst using activated carbon as a non-patent document 1 and a single wall carbon nanotube (SWCNT) as a support body in a non-patent document 2 is applied to an aqueous reforming reaction of an oxygen- have.

However, when the activated carbon is used as the support, it exhibits high surface area and hydrothermal stability. However, due to the irregular pore arrangement, wide pore distribution, and particularly the properties of the activated carbon itself such as micro pores having a small pore size In addition to preventing the reactants from being transported to the catalytic active site in the liquid phase reaction, the products of the gas components generated in the aqueous reforming reaction are not easily released, Which is a cause of lowering the selectivity and production rate of hydrogen in general.

In Patent Document 3, CMK-3 and CMK-5 synthetic carbon having a mesopores of uniform size and uniform pore structure and having a carbon skeleton of a two-dimensional structure are prepared for aqueous reforming reaction Was used as a catalyst support. As a result, the conversion efficiency and the hydrogen production rate of the oxygen-containing hydrocarbon were significantly improved as compared with the conventional activated carbon.

Furthermore, since regular mesoporous carbon supports have various pore structures, they can not only control the pore size but also have high surface area and mesopore volume, and can control the size and shape of the carrier variously. Therefore, The catalytic activity was also higher.

However, since the composite carbon support of the mesoporous CMK-3 and CMK-5 has a micro-particle size, when the support metal is impregnated with platinum, which is an active metal, It has been found that there is a limitation in increasing the reaction activity when the water modification reaction is performed in the aqueous reforming reaction using the catalyst because the mass transfer and diffusion rate of the reactant and the product are low at the active site of the catalyst when the reforming reaction occurs.

As a result, the inventors of the present invention conducted a study to develop a carbon-based carrier for further improving the selectivity of hydrogen and the production of hydrogen in the aquatic reforming reaction. As a result, mesoporous synthetic carbon was used as a catalyst support, When the structure of the carrier is limited to a two-dimensional rod-like or tubular shape and the particle size of the carbon support is limited to nano-size, it is confirmed that the catalyst exhibits improved catalytic performance as an aqueous phase reforming catalyst for producing hydrogen from oxygen-containing hydrocarbons And completed the present invention.

Patent Document 1: Korean Patent Publication No. 2008-0078911 Patent Document 2: WO 2007-075476 Patent Document 3: Korean Patent Publication No. 2011-0109624

Non-Patent Document 1: J.W. Shabaker, G.W. Huber, R.R. Davda, R.D. Cortright, J.A. Dumesic, Catal. Lett. 88 (2003) 1-8 Non-Patent Document 2: X. Wang, N. Li, L.D. Pfefferle, G.L. Haller, Catal. Today. 146 (2009) 160-165

It is an object of the present invention to provide a catalyst for an aquatic reforming reaction for producing hydrogen from oxygen-containing hydrocarbons with improved conversion, production yield and production rate of hydrogen gas.

It is also an object of the present invention to provide a process for producing the catalyst.

Furthermore, it is an object of the present invention to provide a method for producing hydrogen through an aeration reforming reaction of an oxygen-containing hydrocarbon using the catalyst.

In order to achieve the above object,

Platinum as a catalytically active metal is supported on the mesoporous carbon support, the structure of the carbon support is a two-dimensional rod-like or two-dimensional tube, and the average particle size of the carbon support is not less than 50 nm and less than 1000 nm The present invention provides a catalyst for an aqueous reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon.

In addition,

Preparing a two-dimensional cylindrical mesoporous silica mold having an average particle size of from 50 nm to less than 1000 nm (step 1);

(Step 2) of adsorbing a mixture of an aqueous carbohydrate solution and an acid or a carbon polymer precursor in the pores of the mold of step 1 and performing drying and polymerization reaction;

Pyrolyzing and carbonizing the carbon compound polymerized in the pores of the mold of step 2 (step 3);

Removing the template in step 3 to prepare a mesoporous carbon support having an average particle size of 50 nm or more and less than 1000 nm (step 4); And

Impregnating the regular mesoporous carbon support of step 4 with platinum as a catalytically active metal (step 5); The present invention also provides a process for preparing a catalyst for an aqueous reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon.

Further, the present invention relates to a two-dimensional cylindrical mesoporous silica mold having an average particle size of 100 nm or more and less than 1000 nm of the step 1,

_{EO 20 PO 70 EO 20, EO} 27 PO 61 EO 27, EO 17 PO 85 EO 17, EO 20 PO 30 EO 20, EO 26 PO 39 EO 26, EO 13 PO 70 EO 13 and EO ₁₉ PO ₃₃ EO ₁₉ Chinese Language Seine Preparing a structural derivative for a silica template from a mixed solution of one triblock copolymer, hydrochloric acid, water and ammonium fluoride (step a);

Adding a silicate and heptane to the mixed solution of step a to form a complex of a structural derivative and a silicate (step b); And

And a step of calcining the composite of step b) to remove the structural derivative (step c). The present invention also provides a method for preparing a catalyst for an aquatic reforming reaction.

(EO is ethylene glycol and PO is propylene glycol).

The present invention also provides a process for preparing hydrogen from an oxygen-containing hydrocarbon through an aquatic reforming reaction comprising contacting the catalyst with an oxygen-containing hydrocarbon.

The catalyst for aqueous reforming reaction for producing hydrogen from oxygen-containing hydrocarbons according to the present invention uses a mesoporous carbon (OMC) having high surface area, regular pore structure and uniform mesopores as a catalyst support, When the carbon skeleton of the support is limited to a two-dimensional rod or tube shape and the particle size of the support is limited to a specific nano-size, when it is used in an aquatic reforming reaction for producing hydrogen from oxygen-containing hydrocarbons, The production rate and the production rate of hydrogen gas are increased due to the improvement of the dispersion degree of the active metal and the better meso pore structure and the faster mass transfer and diffusion rate than the mesoporous carbon support of the mesoporous carbon support. .

1 is a field emission scanning electron microscope (FE_SEM) photograph of a catalyst carrier of Example 1 - 2 and Comparative Example 1 - 2 according to the present invention:
(a) Example 1: Rod-sized nanoscale CMK-3 mesoporous carbon support catalyst;
(b) Example 2: Tubular nanoscale CMK-5 mesoporous carbon support catalyst;
(c) Comparative Example 1: Rod-sized micro-sized CMK-5 mesoporous carbon support catalyst;
(d) Comparative Example 2: Tubular micro-sized CMK-5 mesoporous carbon support catalyst
2 is a graph showing (a) X-ray diffraction (XRD) and (b) nitrogen adsorption isotherms of a catalyst using a rod-shaped nano-sized CMK-3 mesoporous carbon support according to Example 1 of the present invention : BET (Brunauer-Emmett-Teller) Surface area, total pore volume and pore size are the results from nitrogen adsorption.
3 is a graph showing (a) X-ray diffraction (XRD) and (b) nitrogen adsorption isotherms of a catalyst using a tubular nano-sized CMK-5 mesoporous carbon support according to Example 2 of the present invention: BET (Brunauer-Emmett-Teller) surface area, total pore volume and pore size are the results from nitrogen adsorption.

Hereinafter, the present invention will be described in detail.

The present invention relates to a mesoporous carbon support having platinum supported thereon as a catalytically active metal, the structure of the carbon support is a two-dimensional rod-like or two-dimensional tubular structure, an average particle size of the carbon support is not less than 50 nm and less than 1000 nm Wherein the catalyst is used in an aqueous reforming reaction to produce hydrogen from an oxygen-containing hydrocarbon.

The catalyst according to the present invention is characterized in that mesoporous carbon having a high surface area, regular pore structure and uniform mesopores is supported on a support, and the carbon support structure is formed as a two-dimensional rod or a two-dimensional tube , And the average particle size of the carbon support is in the range of 50 nm to less than 1000 nm. When the average particle size is less than 50 nm, there is a problem that the platinum particles are hardly impregnated into the support. When the support is impregnated with platinum as an active metal in the case of 1000 nm or more, an aqueous reforming reaction is carried out in a high- There is a limitation in increasing the activity of the water modification reaction due to the low mass transfer and diffusion rate of the reactants and products as the active sites of the catalyst.

The catalyst according to the present invention can move the reaction product and the product as a gas component more freely into and out of the pores due to the above characteristics, thereby increasing the frequency at which the reactant reacts at the catalytic active site, , Because it is structurally stable, it has a high hydrothermal stability particularly when applied as a catalyst in a water modification reaction, and it can easily disperse the active metal due to a wider surface area than a conventional micro sized mesoporous carbon support, The conversion rate, the yield and the production rate of the catalyst are remarkably improved.

The catalyst according to the present invention may be a CMK-3 or CMK-5 (CMK: Carbon Mesostructured by KAIST) mesoporous carbon composite material having an average particle size of 50 nm or more and less than 1000 nm as the carbon support. CMK-3 is a two-dimensional rod type, and CMK-5 is a two-dimensional tube type having a high surface area, regular pore structure, and uniform mesopores.

Furthermore, the catalyst according to the present invention is characterized in that the mesoporous carbon support has an average pore size of 2 - 10 nm and an average pore volume of 1.0 - 2.5 cm ³ / g.

The pore size and the pore volume are larger than the pore volume and the pore size of the corresponding micro-sized mesoporous carbon support, so that mass transfer and diffusion rate can be accelerated. It can be used more advantageously in the reforming reaction.

Also, the catalyst according to the present invention may use any one of VIIIB transition metals and VIII transition metals as a catalytically active metal. Among the active metals, platinum is more preferable because it has an advantage of maximizing hydrogen production rate because of high oxygen conversion and hydrogen selectivity in the aquatic reforming reaction.

Further, the catalyst according to the present invention preferably has a platinum content of 1.0 to 10 parts by weight, more preferably 1.0 to 5.0 parts by weight, per 100 parts by weight of the support. If the content of the active metal is less than 1.0 part by weight, the amount of the supported active metal is decreased and the utilization of the activated metal as a catalyst for the water modification reaction is lowered. If the content of the active metal is more than 10 parts by weight, Metal clustering occurs frequently, so that the catalytic activity is not higher than the amount of expensive noble metal catalyst, which is not preferable.

Also, the catalyst according to the present invention can be used in an aquatic reforming reaction for producing hydrogen from oxygen-containing hydrocarbons, and the oxygen-containing hydrocarbons include ethylene glycol, glycerol, propylene glycol, sorbitol, sucros, sugars, sugar alcohols or xylitol may be used.

On the other hand, the present invention relates to a process for producing a two-dimensional cylindrical mesoporous silica mold having an average particle size of 50 nm or more and less than 1000 nm (step 1);

(Step 2) of adsorbing a mixture of an aqueous carbohydrate solution and an acid or a carbon polymer precursor in the pores of the mold of step 1 and performing drying and polymerization reaction;

Pyrolyzing and carbonizing the carbon compound polymerized in the pores of the mold of step 2 (step 3);

Removing the template in step 3 to prepare a mesoporous carbon support having an average particle size of 50 nm or more and less than 1000 nm (step 4); And

Impregnating the regular mesoporous carbon support of step 4 with platinum as a catalytically active metal (step 5); The present invention also provides a process for preparing a catalyst for an aqueous reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon.

Hereinafter, the method for preparing the catalyst for aqueous reforming reaction according to the present invention will be described in more detail.

First, in the method for producing a catalyst for an aqueous reforming reaction according to the present invention, step 1 is a step of preparing a two-dimensional cylindrical mesoporous silica template having an average particle size of 50 nm or more and less than 1000 nm.

Specifically, the step of preparing a two-dimensional cylindrical mesoporous silica mold having an average particle size of 50 nm or more and less than 1000 nm of Step 1,

EO ₂₀ PO ₇₀ EO ₂₀ , EO ₂₇ PO ₆₁ EO ₂₇ , EO ₁₇ PO ₈₅ EO ₁₇ , EO ₂₀ PO ₃₀ EO ₂₀ , EO ₂₆ PO ₃₉ EO ₂₆ , EO ₁₃ PO ₇₀ EO ₁₃ and EO ₁₉ PO ₃₃ EO ₁₉ Preparing a structural derivative for a silica template from a mixed solution of one triblock copolymer, hydrochloric acid, water and ammonium fluoride (step a);

Adding a silicate and heptane to the mixed solution of step a to form a complex of a structural derivative and a silicate (step b); And

Firing the composite of step b) to remove the structural derivative (step c); Wherein the catalyst is prepared by a method comprising the steps of:

(EO is ethylene glycol and PO is propylene glycol).

Patent Document 2 discloses a method for producing a catalyst for an aquatic reforming reaction in which a micro-sized mesoporous carbon support is impregnated with an active metal. The difference between this method and the present invention is that a nano- .

That is, in the production of the nano-sized silica mold according to the present invention, ammonium fluoride (NH ₄ F) is added in the production of the structural derivative for the preparation of the silica mold from the surfactant trifunctional block copolymer as in the step (a) (B), the addition of heptane in the preparation of the composite of the structural derivative and the silicate as described in the above step (b), to prepare a nano-sized silica mold by well dispersing the particles in the aqueous solution during the production of the silica mold There are technical features.

Meanwhile, according to one embodiment of the present invention, EO ₂₀ PO ₇₀ EO ₂₀ may be used as the triblock copolymer, and tetraethyl orthosilicate (TEOS) may be used as the silica silicate.

Next, in the method for preparing a catalyst for aqueous phase reforming according to the present invention, step 2 is a step of adsorbing a mixture of an aqueous solution of carbohydrate and an acid or a precursor of a carbon polymer in the pores of the template of step 1, .

Specifically, the carbon polymer precursor in step 2 or a mixture of the carbohydrate aqueous solution and the acid is used for producing a rod-like carbon carrier, and the carbon polymer precursor may be acetylene, furfuryl alcohol, or divinylbenzene. Carbohydrates An aqueous solution such as sucrose or xylose can be used as the aqueous solution, and sulfuric acid or the like can be used as a catalyst for carbonization of the acid. That is, the catalyst carrier according to the present invention can be produced from a carbohydrate aqueous solution such as sucrose or xylose, thus being environmentally friendly and economical.

Further, the carbon polymer precursor in step 2 is used for producing a tubular carbon carrier, and the carbon polymer precursor may be acetylene, furfuryl alcohol, or divinylbenzene. In particular, the tubular carbon carrier AlCl the silica template for this to be produced is polymerized only in the surface of the silica template ₃ And then the acid sites are formed on the silica surface so that the polymerization of the carbon polymer precursor starts at the acid sites on the silica surface.

Next, in the method for producing a catalyst for an aquatic reforming reaction according to the present invention, step 3 is a step of pyrolyzing a carbon compound polymerized in the pores of the mold of step 2 above. Specifically, the pyrolysis may be performed under nitrogen or vacuum conditions, thereby carbonizing the polymerized carbon compound.

Next, in the method for preparing a catalyst for an aqueous reforming reaction according to the present invention, Step 4 is a step of removing the template of Step 3 to prepare a mesoporous carbon support having an average particle size of 50 nm or more and less than 1000 nm. Specifically, removal of the template may be performed by, for example, a method of etching silica with HF or NaOH solution.

Next, step 5 of the method for preparing an aqueous phase reforming catalyst according to the present invention is a step of impregnating a regular mesoporous carbon support of step 4 with platinum as a catalytically active metal.

Specifically, the impregnation in step 5 may be performed by an impregnation method commonly used in the art, but the incipient wetness method is preferable because uniform dispersion can be achieved when the active metal is dispersed in the carrier. The initial wetting may be performed by adding a solution prepared by dissolving a precursor of an active metal in a solvent to a support.

Meanwhile, the present invention provides a catalyst for an aqueous reforming reaction for producing hydrogen from deoxygenated hydrocarbons produced by the above production method.

Specifically, the catalyst prepared by the process according to the present invention has mesoporous carbon having a high surface area, a regular pore structure and a uniform mesopore as a support, and the carbon support structure has a two-dimensional rod, Or a two-dimensional tube shape, and the average particle size of the carbon support is in the range of 50 nm to less than 1000 nm.

The catalyst prepared by the process according to the present invention can increase the frequency at which the reactant reacts at the catalytic active site because the reactant and the product as a gas component can move more freely into and out of the pores due to the above characteristics, Speed and can be imparted with a high structural stability, so that it has a high hydrothermal stability particularly when applied as a catalyst in an aqueous reforming reaction, and also because of the wider surface area than conventional micro sized mesoporous carbon supports, So that the conversion, yield and production rate of hydrogen can be remarkably improved.

Furthermore, the catalyst prepared by the process according to the present invention is characterized in that the mesoporous carbon support has an average pore size of 2 - 10 nm and an average pore volume of 1.0 - 2.5 cm ³ / g.

The pore size and the pore volume are larger than the pore volume and the pore size of the corresponding micro-sized mesoporous carbon support, so that mass transfer and diffusion rate can be accelerated. It can be used more advantageously in the reforming reaction.

The present invention also provides a process for preparing hydrogen from an oxygen-containing hydrocarbon through an aquatic reforming reaction comprising contacting the catalyst according to the present invention with an oxygen-containing hydrocarbon.

Hereinafter, a method for preparing hydrogen through the aquatic reforming reaction from the oxygen-containing hydrocarbon according to the present invention will be described in detail.

Specifically, in the method for producing hydrogen according to the present invention, the step of contacting the catalyst with the oxygen-containing hydrocarbon may be performed by injecting oxygen-containing hydrocarbon into the fixed-bed reactor filled with the catalyst for the aquatic reforming reaction.

Further, in the method for producing hydrogen according to the present invention, the water modification reaction is preferably carried out at a temperature in the range of 200 to 300 ° C. If the reaction temperature is lower than 200 ° C, there is a problem that the reaction activity is too low, and when the reaction temperature is higher than 300 ° C, the hydrogen gas conversion rate is lowered, which is not preferable.

Further, in the method for producing hydrogen according to the present invention, the water reforming reaction is carried out while supplying the oxygen-containing hydrocarbon to the reactor at a weight hour space velocity (WHSV) in the range of 0.01 to 5.0 cc / g cat.min desirable. When the weight-space velocity is less than 0.01 cc / gcat.min, the reactant injection amount is too small to cause a phenomenon of channeling in one direction in the reactor, There is a problem that the conversion rate of the reactant is too low.

When the catalyst according to the present invention is adapted to an aquatic reforming reaction for producing hydrogen from an oxygenated hydrocarbon, the reaction product reacts at the catalytic active site because the reactant and the product of the gas component can move more freely into and out of the pore It is possible to increase the frequency, to give a fast diffusion rate, and because it is structurally stable, it has not only high hydrothermal stability when applied as a catalyst in a water reforming reaction, but also has a wider surface area than conventional micro sized mesoporous carbon supports The dispersion of the active metal can be facilitated, so that the conversion, yield and production rate of hydrogen can be remarkably improved.

Hereinafter, the present invention will be described in detail with reference to the following examples and experimental examples.

However, the following examples and experimental examples are illustrative of the present invention, but are not limited thereto.

< Example  1> Nano-sized  Bar Mesoporous CMK -3 Carbon support  catalyst

Manufacturing example  One: Nano-sized Mesoporous SBA -15 Preparation of silica mold

144 g of EO ₂₀ PO ₇₀ EO ₂₀ (trade name: Pluronic P ₁₂₃ , EO: ethylene glycol, PO: propylene glycol), 1.68 g of ammonium fluoride (NH4F) and 850 g of hydrochloric acid (HCL) do. Next, when Pluronic P ₁₂₃ is completely dissolved, 690 g of tetraethyl orthosilicate (TEOS) as a silica and 310 g of heptane are added and stirred vigorously. Next, if the mixed solution becomes an emulsion form, it is aged for 3 - 4 hours in that state, and then it is heated in an oven at 100 ° C. for 24 hours. Next, the prepared reaction product was washed with distilled water, dried at 100 ° C., and then fired at 550 ° C. for 5 hours to remove Pluronic P ₁₂₃ , thereby preparing 199 g of nano-sized cylindrical mesoporous SBA-15 silica mold .

Preparation Example 2: Preparation of nanoscale mesoporous aluminosilicate Al-SBA-15

Next, to make a nano-sized mesoporous Al-silicate-type Al-SBA-15 mold, 0.111 g of AlCl ₃ (Si / Al = 1 mol) per gram of the SBA-15 silica mold prepared in Step 1 of Example 1, 20) was mixed with 50 ml of the ethanol solution and stirred well for about 30 minutes. The ethanol was removed by evaporation, dried and then calcined at 550 ° C for 5 hours to obtain a nano-sized mesoporous aluminosilicate Al-SBA-15 .

Preparation Example 3: Preparation of nano-sized mesoporous CMK-3 carbon support

Ten grams of nano-sized mesoporous silica Al-SBA-15 was impregnated with 8.5 g of furfuryl alcohol in five steps, spread at 35 DEG C for 1 hour, heated to 100 DEG C for 1 hour, dried at 350 DEG C For 3 hours to initial carbonize. Subsequently, the mesoporous silica / carbon composite was impregnated again with 5.5 g of furfuryl alcohol, spread at 35 DEG C for 1 hour, and dried at 100 DEG C for 1 hour. Subsequently, the carbonization is initially carbonized at 350 ° C for 3 hours, and finally carbonated at 900 ° C for 2 hours. The silica / carbon composite composite thus prepared was washed and filtered twice with ethanol and distilled water by dissolving silica by etching the silica material twice using a 10% HF solution, For 12 hours or longer to prepare nano-sized CMK-3 support.

Manufacturing example  4: Supporting platinum Nano-sized Mesoporous CMK -3 Carbon support  Preparation of Catalyst

First, 0.1850 g of hexachloroplatinic acid (H ₂ PtCl ₆ ) as a precursor of platinum and 3 ml of acetone were mixed to prepare a homogeneous solution. Then, using the initial wetting method, The mesoporous CMK-3 carbon support was impregnated with platinum. That is, 1.0 g of the carbon carrier was poured into the prepared platinum precursor mixture solution three times, mixed well using a voltex unit, stuck at room temperature for about 1 hour, Was dried at 60 DEG C for 2 hours in a slightly opened state, and then further dried at 60 DEG C for 6 hours with the lid of the glass bottle completely opened. Finally, the catalyst was dried at 120 ° C for 12 hours to complete the preparation of the catalyst of Example 2. The prepared catalyst was named 7 wt% Pt / Nano-CMK-3.

< Example  2> Tubular type Nano-sized CMK -5 Carbon support  catalyst

Manufacturing example  One: Nano-sized Mesoporous SBA -15 Preparation of silica mold

A cylindrical nano-sized mesoporous SBA-15 silica mold was prepared in the same manner as in Preparation Example 1 of Example 1.

Manufacturing example  2: Nano-sized Mesoporous Aluminosilicate Al - SBA Manufacture of -15

Next, to make a nano-sized mesoporous Al-silicate-type Al-SBA-15 mold, 0.111 g of AlCl ₃ (Si / Al = 1 mol) per gram of the SBA-15 silica mold prepared in Step 1 of Example 1, 20) was mixed with 50 ml of the ethanol solution and stirred well for about 30 minutes. The ethanol was removed by evaporation, dried and then calcined at 550 ° C for 5 hours to obtain a nano-sized mesoporous aluminosilicate Al-SBA-15 .

Manufacturing example  3: Nano-sized Mesoporous CMK -5 Carbon support  Produce

In the case of nano-sized CMK-5, 8.5 g of furfuryl alcohol was impregnated stepwise 5 times in 10 g of mesoporous silica Al-SBA-15, and then prepared in the same manner as in CMK-3 under vacuum.

Manufacturing example  4: Supporting platinum Nano-sized Mesoporous CMK -5 Carbon support  Preparation of Catalyst

The procedure of Preparation Example 4 of Example 1 was followed to prepare a catalyst impregnated with platinum in a nano-sized mesoporous CMK-5 carbon support. The prepared catalyst was designated as 7 wt% Pt / Nano-CMK-5 Respectively.

< Comparative Example  1> bar size micro size CMK -3 Carbon support  catalyst

The same procedure as in Example 1 was carried out except that ammonium fluoride (NH4F) and heptane were not used in Preparation Example 1 of Example 1 to prepare the rod-like micro-sized CMk-3 carbon felds of Comparative Example 1 The late catalyst was prepared and the prepared catalyst was named 7 wt% Pt / Micro-CMK-3.

< Comparative Example  2> tubular micro-sized CMK -5 Carbon support  catalyst

The same procedure as in Example 1 was carried out except that ammonium fluoride (NH4F) and heptane were not used in Preparation Example 1 of Example 2 to obtain a rod-like micro-sized CMk-3 carbon fiber of Comparative Example 1 The late catalyst was prepared and the prepared catalyst was named 7 wt% Pt / Micro-CMK-3.

< Experimental Example  1> catalyst Carrier  Property evaluation

The physical properties of the nanoscale mesoporous CMK-3 and CMK-5 carbon supports of Example 1-2 according to the present invention and the micro-sized mesoporous CMK-3 and CMK-5 carbon supports of Comparative Example 1-2 For evaluation, FIG. 1 shows the field emission scanning electron microscopic photographs of the above-mentioned carbon carriers, XRD diffraction analysis and nitrogen adsorption / desorption isotherms are shown in FIG. 2 (nanoscale mesoporous CMK-3) and FIG. 3 Size mesoporous CMK-5). Further, the particle size of the carbon support, the BET surface area obtained from the nitrogen adsorption, the pore volume and the pore size are shown in Table 1 below.

catalyst Carrier  Comparison of physical properties matter Average particle size
(μm) BET surface area
(m ² / g) Pore volume
(cm &lt; ³ &gt; / g) Pore Size
(nm) Micro SBA-15 - 807 0.84 8.0 Comparative Example 1:
Micro CMK-3 3.0 1124 1.10 3.8 Comparative Example 2:
Micro CMK-5 3.0 1630 1.49 3.2, 4.4 Nano SBA-15 - 412 0.90 10.9 Example 1:
Nano CMK-3 0.5 977 1.28 6.5 Example 2:
Nano CMK-5 0.5 1550 2.27 4.0, 8.3

1, the average particle size of the nano-sized mesoporous CMK-3 and CMK-5 carbon supports of Example 1 - 2 according to the present invention was 500 nm, It can be confirmed that the shape is a two-dimensional bar shape (tube shape is not shown).

Further, the pore volume and pore size of the nano-sized mesoporous CMK-3 and CMK-5 carbon supports according to the present invention were measured using micro-sized CMK-3 and CMK-5 carbon supports In comparison with the other groups.

In addition, it can be seen that, in the case of the tubular CMK-5 carbon carrier, one additional mesopore is generated because the mesopores in the inner side of the tube are additionally formed in addition to mesopores of uniform size between the carbon rods .

< Experimental Example  2> Water reform  Evaluation of Catalyst Performance by Reaction

In order to confirm the catalyst performance in the aquatic reforming reaction for producing hydrogen from the deoxygenated hydrocarbon of the catalyst according to the embodiment of the present invention, the catalyst of Example 1 - 2 and Comparative Example 1 - The hydrogen gas conversion rate, the yield of hydrogen, and the rate of hydrogen generation were calculated, and the results are shown in Tables 2 and 3 below.

Catalyzed Ethylene Glycol and Glycerol Water reform  reaction

Specifically, the performance evaluation of the catalyst by the aqueous reforming reaction of the polyol was carried out using a 1/2 inch tubular fixed bed catalytic reaction system. The amount of the catalyst used was 0.3 g. After the reaction was reduced to 260 ° C under hydrogen flow for 6 hours before the reaction, a 0.1 wt% polyol aqueous solution (Table 2: aqueous ethylene glycol solution, Table 3: glycerol aqueous solution) min. &lt; / RTI &gt; Next, the weight hour space velocity (WHSV) was fixed to 0.1 cc / gcat.min, and the temperature and pressure were kept constant at 250 ° C. and 45 atm. Hydrogen was produced.

Calculation of hydrogen gas conversion rate, hydrogen yield and hydrogen production rate

The gaseous products produced after the water reforming reaction were analyzed using a GC-TCD equipped with a carboxen 1000 packed column and a GS-GASPRO capillary column using nitrogen as an internal standard And quantitatively analyzed by FID. The conversion rate of the polyol to the hydrogen gas, the yield of hydrogen, and the production rate of hydrogen based on the carbon component in the reaction raw materials were calculated using the following Equation 1 - 3. Further, the higher the gas conversion rate based on the carbon content in the reaction raw material, the higher the production amount of hydrogen is.

[Equation 1]

&Quot; (2) &quot;

(In the case of ethylene glycol: (CH ₂ ) ₂ (OH) ₂ + 2H ₂ O → 2CO ₂ + 5H ₂

Glycerol Reaction formula: C ₃ H ₅ (OH) ₃ + 3H ₂ O → 3CO ₂ + 7H ₂

&Quot; (3) &quot;

The rate of hydrogen production (cc / gcat.min) = the rate of hydrogen production per minute per gram of catalyst after quantifying the amount of hydrogen detected in the TCD of the GC, based on the internal standard of nitrogen.

Of ethylene glycol Water reform  Evaluation of catalyst performance in reaction division Type of catalyst used Conversion of hydrogen gas
(%) The yield of hydrogen
(%) Hydrogen production rate
(cc / gcat.min) Example 1 7 wt% Pt / nano-CMK-3 73.4 75.2 50.1 Example 2 7 wt% Pt / nano-CMK-5 88.0 86.3 57.5 Comparative Example 1 7 wt% Pt / micro-CMK-3 70.4 72.6 45.1 Comparative Example 2 7 wt% Pt / Micro-CMK-5 79.5 77.0 53.3

Glycerol Water reform  Evaluation of catalyst performance in reaction division Type of catalyst used Conversion of hydrogen gas (%) The yield of hydrogen
(%) Hydrogen production rate
(cc / gcat.min) Example 1 7 wt% Pt / nano-CMK-3 55.4 50.1 35.6 Example 2 7 wt% Pt / nano-CMK-5 73.8 62.9 44.7 Comparative Example 1 7 wt% Pt / micro-CMK-3 47.8 38.1 27.1 Comparative Example 2 7 wt% Pt / Micro-CMK-5 56.0 53.9 38.3

As a result, as shown in Tables 2 and 3, although the same amount of the platinum catalytically active metal was loaded, the conversion rate of hydrogen gas, the yield of hydrogen, and the rate of hydrogen generation differ depending on the type of the carrier Can be confirmed.

Specifically, the nano-sized mesoporous CMK-3 and CMK-5 carbon support catalysts of Examples 1 and 2 according to the present invention exhibited a higher conversion rate of hydrogen gas, hydrogen And the production rate of hydrogen is high. This is because the surface area increase due to the nano-sized particle size of the microcavities of the catalyst carrier of Examples 1 and 2 according to the present invention and the mesoporous structure of the carrier are more developed than the micro-sized carrier It is believed that this is because the degree of dispersion of the active metal is improved and the material migration and diffusion rate is not only faster but also has high hydrothermal stability.

On the other hand, in the case of the tubular support catalyst of Example 2 and Comparative Example 2, it can be confirmed that the conversion rate of hydrogen gas, the yield of hydrogen and the generation rate of hydrogen are higher than that of the corresponding rod-shaped support catalyst. This is considered to be because the tubular support has a larger surface area than the rod-like support and has additional mesopores, so that the catalytically active metal is uniformly dispersed in the carbon support and diffusion of the reactants and products is good.

From the above experimental results, the nanosized mesoporous carbon support catalyst according to the present invention has the effect of further improving the conversion rate of hydrogen gas, the yield of hydrogen and the production rate of hydrogen, compared with the conventional mesoporous mesoporous carbon catalyst , It can be used as a catalyst for an aqueous reforming reaction for producing hydrogen from oxygen-containing hydrocarbons.

Claims (10)

Platinum as a catalytically active metal is supported on the mesoporous carbon support, the structure of the carbon support is a two-dimensional rod-like or two-dimensional tube, and the average particle size of the carbon support is not less than 50 nm and less than 1000 nm A catalyst for an aqueous reforming reaction for producing hydrogen from oxygen-containing hydrocarbons.
The catalyst for an aqueous modification reaction according to claim 1, wherein the mesoporous carbon support is CMK-3 or CMK-5 (CMK: Carbon Mesostructured by KAIST) having an average particle size of 50 nm or more and less than 1000 nm.
The catalyst for an aquatic reforming reaction according to claim 1, wherein the mesoporous carbon support has an average pore size of 2 - 10 nm.
The catalyst for an aqueous reforming reaction according to claim 1, wherein the mesoporous carbon support has an average pore volume of 1.0 - 2.5 cm ³ / g.
The catalyst for an aquatic reforming reaction according to claim 1, wherein the content of platinum as the catalytically active metal is 1 to 10 parts by weight based on 100 parts by weight of the carrier.
The catalyst for an aqueous reforming reaction according to claim 1, wherein the oxygen-containing hydrocarbon is at least one selected from the group consisting of ethylene glycol, glycerol, propylene glycol, sorbitol, sucrose, sugar, sugar alcohol and xylitol.
Preparing a two-dimensional cylindrical mesoporous silica mold having an average particle size of 50 nm or more and less than 1000 nm (step 1);
(Step 2) of adsorbing a mixture of an aqueous carbohydrate solution and an acid or a carbon polymer precursor in the pores of the mold of step 1 and performing drying and polymerization reaction;
Pyrolyzing and carbonizing the carbon compound polymerized in the pores of the mold of step 2 (step 3);
Removing the template in step 3 to prepare a mesoporous carbon support having an average particle size of 50 nm or more and less than 1000 nm (step 4); And
Impregnating the regular mesoporous carbon support of step 4 with platinum as a catalytically active metal (step 5);
Wherein the hydrogen-containing hydrocarbon is a hydrogen-containing hydrocarbon.
8. The method of claim 7, wherein the step of preparing a two-dimensional cylindrical mesoporous silica mold having an average particle size of 50 nm or more and less than 1000 nm,
EO ₂₀ PO ₇₀ EO ₂₀ , EO ₂₇ PO ₆₁ EO ₂₇ , EO ₁₇ PO ₈₅ EO ₁₇ , EO ₂₀ PO ₃₀ EO ₂₀ , EO ₂₆ PO ₃₉ EO ₂₆ , EO ₁₃ PO ₇₀ EO ₁₃ and EO ₁₉ PO ₃₃ EO ₁₉ Preparing a structural derivative for a silica template from a mixed solution of one triblock copolymer, hydrochloric acid, water and ammonium fluoride (step a);
Adding a silicate and heptane to the mixed solution of step a to form a complex of a structural derivative and a silicate (step b); And
Firing the composite of step b) to remove the structural derivative (step c);
Wherein the catalyst is prepared by a method comprising the steps of:
(EO is ethylene glyglycol and PO is propylene glycol).
A catalyst for an aqueous reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon produced by the process of claim 7.
A process for the production of hydrogen via an aquatic reforming reaction from an oxygen-containing hydrocarbon comprising contacting the catalyst of claim 1 or 9 with an oxygen-containing hydrocarbon.

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