KR101468208B1 - Nano-sized Mesoporous Carbon Supported Catalyst by Dry-Gel Method for Aqueous Phase Reforming Reaction and Preparing Method Thereof - Google Patents

Abstract

The present invention relates to a nano-sized mesoporous carbon support catalyst for an aquatic reforming reaction prepared by a dry-gel method and a method for producing the same, and the catalyst of the present invention is characterized in that the shape of the carbon support is a three- And has an average particle size of 300 to 600 nm. When the catalyst is used as a catalyst for an aqueous modification reaction, the catalytic performance is improved as compared with a conventional micro-sized mesoporous carbon support, thereby improving hydrogen selectivity and hydrogen production The present invention also provides a method for preparing a catalyst for modification of water by using a conventional method for preparing a nanoscale mesoporous silica template for producing a carbon carrier by a template synthesis method, Since the dry-gel (DGC) method is applied instead of the conventional method, the environmental problems due to the use of conventional solvents, It is possible to solve the problem of irregularity of the foot and the particles, and thus it can be more usefully used as a method for producing a catalyst for an aqueous reforming reaction.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nano-sized mesoporous carbon support catalyst for a water-reforming reaction prepared by a dry-gel method, and a method for producing the same.

The present invention relates to a process for preparing a mesoporous carbon support having a nanometer size by using a silica template prepared by a dry gel method (DGM) A process for preparing the same, and a process for producing hydrogen from an oxygen hydrocarbon through an aquatic reforming reaction.

The water reforming reaction refers to a technique for selectively producing hydrogen from an oxygen-containing hydrocarbon such as glucose derived from biomass, a variety of polyol aqueous solutions such as sugar, methanol, glycerol, ethylene glycol, sorbitol, sugar alcohol and the like. This water reforming reaction was first proposed by Professor Dymejic of Wisconsin, USA, and the reforming reaction and the water-gas shift (WGS) reaction in one reactor were carried out at 300 ° C JW Shabaker, JA Dumesic, Science, 300 (27), (2003), 2075, JW (2003)), the concentration of carbon monoxide (CO) Shabaker, GW Huber, RR Davda, RD Cortright, JA Dumesic, Catal. In particular, this water reforming reaction has the advantage of using raw materials derived from biomass, which is an alternative to petroleum, in preparation for depletion of crude oil in the future.

The steam reforming reaction using naphtha or natural gas as a raw material, which is a typical method of producing hydrogen, has been attracting much attention. This conventional reaction has a problem that the reaction takes place at a high temperature of 900 ° C or higher, and the energy consumption cost is very high, and carbon monoxide (CO) equal to or more than hydrogen is generated at the same time. That is, in the steam reforming reaction, hydrogen and carbon monoxide are produced at a molar ratio of 3 to 5 mol, and therefore, there is a limitation that a separate water gas conversion reaction and a methanation reaction step are required to reduce the carbon monoxide to 100 ppm or less in order to produce hydrogen have.

On the other hand, the method of producing hydrogen by the water reforming reaction pursuant to the present invention is characterized in that only hydrogen is selectively produced, and by-products such as carbon monoxide and methane, which exhibit toxicity, hardly occur.

Therefore, studies on this aquatic reforming reaction are variously carried out for the purpose of selectively producing hydrogen from an oxygenated carbohydrate compound in aqueous solution induced by hydrolysis from biomass, which is a renewable energy resource in preparation for depletion of petroleum have. In other words, in order to produce various chemical products and clean fuel from biomass, it is necessary to remove oxygen-containing compounds contained in the biomass in each stage reaction, in which hydrogen must be used indispensably. In particular, biomass is mainly cultivated in a location where hydrogen supplied from existing petrochemical complexes can not be used. In order to produce such a variety of chemical products and clean fuel by directly producing such hydrogen in the cultivation area of biomass, It is a very suitable process.

On the other hand, the chemical reaction of the aqueous reforming reaction is mainly an active metal component, a feedstock to be fed, a reaction condition, and a catalyst carrier. Therefore, in order to selectively produce hydrogen from deoxygenated hydrocarbons by the water reforming reaction, it is necessary to appropriately perform the mass transfer and the reaction on the surface of the catalytic metal, in which the reactant comprising the liquid phase reaches the reaction active site. The carbon-carbon cleavage reaction of the reactants should be maximized while the cleavage rate of the carbon-oxygen bonds of the reactants and the methanation / Fischer-Tropsch reaction should be suppressed. Therefore, it is necessary to select appropriate catalysts and control the reaction parameters.

Particularly, since the catalyst carrier having a porous structure greatly affects the water modification reaction in which the mass transfer of the liquid material must be performed, much research has been conducted on this. As a representative method of preparing a carrier, there are known a method using a metal oxide and a method using a carbon carrier. However, generally known Al ₂ O ₃ , ZrO ₂ , SiO ₂ , CeO ₂ , ZnO or TiO ₂ Is used as a support, the oxide is sintered at a temperature of about 200 - 300 ° C, which is a reaction condition under which aquatic modification usually occurs, and a high-pressure aqueous solution required for maintaining the liquid at this temperature, Phase transition occurs in a form that collapses or reduces the specific surface area of the carrier in a wide range of meta stable phases.

Therefore, in order to solve the problems of the method using the metal oxide, a porous carbon support excellent in hydrothermal stability has been attracting attention and various studies have been made. The porous carbon support is advantageous in that it can disperse active metal components to be impregnated and has a large surface area, suitable pore volume, and mechanical / chemical stability that can promote the reaction in a liquid phase.

Conventionally, Patent Documents 1 and 2 disclose an example in which a catalyst in which a VIIB group transition metal and a VIII group transition metal are impregnated with vulcan carbon as a carbon support is applied to an aqueous reforming reaction of an oxygen-containing hydrocarbon.

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.

Patent Document 3 discloses that CMK-3 and CMK-5 synthetic carbon having a mesopores of regular size and uniform size and a carbon skeleton of two-dimensional structure are treated with a water-modified Was used as the support of the reaction catalyst. As a result, the conversion efficiency and the hydrogen production rate of the hydrocarbons were significantly improved as compared with the case of using the known activated carbon. Particularly, since the regular mesoporous carbon support has various pore structures, the pore size can be controlled In addition, it has a high surface area and a mesopore volume, and can control the size and shape of the carrier variously, which is advantageous in catalytic activity compared to carbon nanotubes.

However, since the synthetic carbon carrier of the mesoporous CMK-3 and CMK-5 has a micro (μm) size of aggregated particles, the catalyst is prepared by impregnating the carrier with platinum, which is an active metal, , It is found that when the water modification reaction occurs in a high-pressure aqueous solution, the mass transfer and diffusion rate of the reactant and the product to the active site of the catalyst is low and thus there is a limit to increase the reaction activity when used in the water modification reaction Respectively.

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 tube-like shape and the particle size of the carbon support is limited to nano-size, it exhibits an improved catalytic performance as an aqueous reforming catalyst for producing hydrogen from oxygen- It is confirmed in Patent Application No. 10-2012-0143346.

However, the catalyst disclosed in the Korean Patent Application No. 10-2012-0143346 has a problem in that ammonia fluoride (NH ₄ F) is used as an additive to prepare nanoscale mesoporous silica molds for producing nanoscale mesoporous synthetic carbon In order to use n-alkane as a dispersant for making nano-sized particles, it is necessary to use a large amount of n-alkane solvent having 5 to 16 carbon atoms. Therefore, environmental problems due to solvent use, volatilization of solvent, It is pointed out that the size is irregular.

Thus, the present inventor has continued research on easily synthesizing a nano-sized mesoporous carbon support capable of improving hydrogen selectivity, hydrogen production amount and production rate in a water reforming reaction, and as a result, In the case of synthesizing a carbon carrier by a template synthesis method using a dry-gel (DGC) method instead of the conventional additives and dispersants for producing a silica template, A mesoporous carbon support having a relatively uniform size with an average particle size of 300 to 600 nm in an ellipse or a spherical shape can be prepared and the catalyst performance can be improved when a water reforming reaction is carried out using a catalyst impregnated with an active metal And the hydrogen selectivity, the hydrogen production rate and the production rate are improved, and the present invention has been completed.

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 preparing the catalyst without the use of additional solvents.

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,

Characterized in that a catalytically active metal is carried on a regular mesoporous carbon carrier, the shape of the carbon carrier is a three-dimensional ellipsoidal or spherical shape, and an average particle size is 300 to 600 nm. The present invention provides a catalyst for an aqueous reforming reaction for producing hydrogen from hydrogen.

In addition,

Preparing a mesoporous silica mold having a three-dimensional elliptical or spherical shape with an average particle size of 300 to 600 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 mold of step 3 to produce a mesoporous carbon support (step 4); And

Impregnating the mesoporous carbon support of step 4 with 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,

In the method for producing a catalyst for an aqueous reforming reaction, the step of preparing a mesoporous silica mold having a three-dimensional elliptic or spherical shape with an average particle size of 300 to 600 nm in Step 1,

Preparing a structural derivative for a silica template from a mixed solution of a copolymerized organic solvent, hydrochloric acid and water (step a);

Adding a silica precursor to the mixed solution of step a) to form a structural derivative / silica complex (step b);

Drying the composite of step b), pulverizing and pulverizing (step c);

Hydrothermally synthesizing the powder of step c by contacting it with water vapor (step d); And

(D) removing the structural derivative by drying and then firing the hydrothermally synthesized solid of step d);

The present invention also provides a process for preparing an aqueous phase reforming catalyst.

The present invention also provides a catalyst for an aqueous reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon produced by the above production method.

Further, the present invention provides a process for preparing hydrogen from an oxygen-containing hydrocarbon through an aquatic reforming reaction, comprising the step of contacting the catalyst for a water-reforming reaction with an oxygen-containing hydrocarbon.

The catalyst for an aqueous reforming reaction for producing hydrogen from oxygen-containing hydrocarbons according to the present invention uses a mesoporous carbon (OMC) having a high surface area, regular pore structure and uniform mesopores as a catalyst support, When the carbon carrier is in the form of a three-dimensional ellipse or spherical shape and has an average particle size of 300 to 600 nm, when the catalyst is used as a catalyst for an aeration reforming reaction, catalytic performance The hydrogen selectivity and the hydrogen production amount can be improved.

The present invention also provides a method for preparing a catalyst for an aquatic reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon according to the present invention, which comprises the steps of: preparing a nanoscale mesoporous silica template for producing a carbon carrier by a template synthesis method; Since the dry-gel method is applied instead of using additives and dispersants, it is possible to solve the problems of environmental problems caused by the use of conventional solvents, volatilization of solvents and particle irregularities, Since the prepared carbon carrier has a three-dimensional ellipsoidal shape or spherical shape and has an average particle size of 300-600 nm and a relatively constant size, when the aqueous reforming reaction is carried out using a catalyst impregnated with an active metal, And the hydrogen selectivity and the hydrogen production rate are further improved.

FIG. 1 shows a method of preparing a nanoscale mesoporous SBA-15 silica mold by a dry-gel method according to an embodiment of the present invention.
2 is a field emission scanning electron microscope (FE_SEM) photograph of the catalyst carrier of Example 1 - and Comparative Example 1 - 2 according to the present invention:
(a) Comparative Example 1: Micro-sized CMK-3 catalyst
(b) Example 1: DGC-nano-CMK3 catalyst (using the dry-gel method).
3 is a graph showing the nitrogen adsorption isotherms of Example 1 (DGC-nano-CMK3) and Example 2 (DGC-nano-CMK5) catalysts according to the invention; The BET (Brunauer-Emmett-Teller) surface area, total pore volume and pore size are the results from nitrogen adsorption.
4 is a graph of X-ray diffraction analysis results of Example 1 (DGC-nano-CMK-3) and Example 2 (DGC-nano-CMK-5) according to the present invention; (a) Small Angle XRD, (b) Wide angle XRD.

The present invention relates to a method for producing a nanoscale mesoporous carbon support by using a silica mold produced by a dry gel method (DGM) The present invention relates to a catalyst for an aqueous reforming reaction for producing hydrogen from hydrogen peroxide, a process for preparing the same, and a process for producing hydrogen from an oxygen hydrocarbon through an aquatic reforming reaction.

Hereinafter, the present invention will be described in detail.

The present invention

Characterized in that a catalytically active metal is carried on a regular mesoporous carbon carrier, the shape of the carbon carrier is a three-dimensional ellipsoidal or spherical shape, and an average particle size is 300 to 600 nm. The present invention provides a catalyst for an aqueous reforming reaction for producing hydrogen from hydrogen.

Specifically, the catalyst for aqueous phase reforming according to the present invention comprises mesoporous carbon having a high surface area, regular pore structure and uniform mesopores as a support, and the shape of the carbon support is a three-dimensional ellipsoidal or spherical shape, The average particle size of the carbon support is characterized by a nanoscale size of 300-600 nm.

Furthermore, the catalyst according to the present invention can move the reactant and the product of the 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, And because it is structurally stable, not only has high hydrothermal stability when applied as a catalyst in a water reforming reaction, but also facilitates the dispersion of the active metal due to the wider surface area compared with conventional micro sized mesoporous carbon supports Therefore, there is an advantage that the performance of the catalyst such as the selectivity of hydrogen, the yield and the production rate of hydrogen can be remarkably improved.

Further, 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.

Specifically, 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 speed can be accelerated. And thus can be more effectively used in an aqueous reforming reaction.

In addition, the catalyst according to the present invention can be selected from any one of transition metals of Group VIIB and transition metals of Group VIII as the catalytically active metal. Particularly, platinum has high oxygen conversion and hydrogen selectivity in the aqueous reforming reaction, It is more preferable because it has an advantage of maximizing the generation speed.

Furthermore, the content of the catalytically active metal in the catalyst according to the present invention is preferably 1.0 to 10 parts by weight, more preferably 1.0 to 5.0 parts by weight based on 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 active metal supported is small and the utilization of the active metal as a catalyst for the aquatic reforming reaction is lowered. If the content of the active metal is more than 10 parts by weight, There is a problem that the catalytic activity is not higher than the amount of the expensive noble metal catalyst, and it is preferable to maintain the above range.

In addition, 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.

Further,

Preparing a mesoporous silica mold having a three-dimensional elliptical or spherical shape with an average particle size of 300 to 600 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 mold of step 3 to produce a mesoporous carbon support (step 4); And

Impregnating the mesoporous carbon support of step 4 with 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, a method for preparing a catalyst for an aquatic reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon according to the present invention will be described in more detail.

First, in the method for preparing a catalyst for an aqueous reforming reaction according to the present invention, Step 1 is a step of preparing a mesoporous silica mold having a three-dimensional elliptic or spherical shape with an average particle size of 300 to 600 nm.

Specifically, the step of preparing the mesoporous silica mold having the average particle size of 300 to 600 nm in the step 1 as the three-dimensional ellipsoidal or spherical mesoporous silica mold,

Preparing a structural derivative for a silica template from a mixed solution of a copolymerized organic solvent, hydrochloric acid and water (step a);

Adding a silica precursor to the mixed solution of step a) to form a structural derivative / silica complex (step b);

Drying the composite of step b), pulverizing and pulverizing (step c);

Hydrothermally synthesizing the powder of step c by contacting it with water vapor (step d); And

The step (e) of removing the structural derivative by drying and then firing the hydrothermally synthesized solid of step d); And the like.

The present inventors have proposed a method for preparing a catalyst for an aqueous reforming reaction in which a micro-sized mesoporous carbon support is impregnated with an active metal in Patent Document 3 (Korean Patent Publication No. 2011-0109624) Is that nano-sized silica molds are produced in order to prepare nano-sized catalysts for aqueous reforming reaction.

That is, in the process for preparing a catalyst for an aqueous phase reforming reaction according to the present invention, in order to prepare a nano-sized mesoporous silica template, an additive agent and a spraying agent are not used but a dry-gel method is applied And has the advantage of solving the problems of environmental problems, volatilization of solvents and irregularity of particles when a solvent is used to manufacture a conventional nano-sized silica mold.

Specifically, in the preparation of a structural derivative for the preparation of a silica template from a trifunctional block copolymer as an organic solvent, as in step (a), hydrochloric acid (HCl) is added without using an additional additive (ammonia fluoride (NH ₄ F) (N-alkane having 5 to 16 carbon atoms) is not used in the preparation of the structural derivative / silica composite as in the step (b), and the step (c) The solid derivative / silica composite thus prepared is placed in an inner vessel in a high-pressure hydrothermal reactor as in step (d), distilled water of the outer vessel is evaporated, and the resultant is subjected to hydrothermal synthesis in contact with the internal solid component. There is a technical feature that nano-sized mesoporous silica molds are produced by firing to remove the structural derivatives.

The high-pressure hydrothermal reaction for preparing the silica mold of step d is preferably performed at 100 to 150 ° C. for 1 to 72 hours. If the reaction temperature is lower than 100 ° C, there is a problem that distilled water is not evaporated. If the reaction temperature is higher than 150 ° C, the triblock copolymer used as a template has a problem due to high temperature. When the reaction time is less than 1 hour, the high-pressure hydrothermal reaction does not proceed sufficiently, and when the reaction time exceeds 72 hours, the triple block copolymer used as a template decomposes.

Also, the organic sibling of step 1 may be a trifunctional block copolymer which is a surfactant. Examples thereof include 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 (EO is ethylene glycol, and PO is propylene glycol).

Further, the silica precursor of Step 1 is not particularly limited as long as it is a silica precursor used for preparing a silica template for synthesizing mesoporous carbon by a template synthesis method. For example, silicate may be used as a silica precursor, Tetraethyl orthosilicate (TEOS) can be selected and used.

In addition, the silica template prepared in Step 1 was mixed with AlCl 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 surface of the silica.

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, acetylene, furfuryl alcohol, and divinyl benzene may be used as the carbon polymer precursor in step 2, and an aqueous solution such as sucrose or xylose may be used as the carbohydrate aqueous solution. The acid may be sulfuric acid Etc. may be used. 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.

Next, in the method for producing the catalyst for water-reforming reaction according to the present invention, Step 3 is a step of pyrolyzing and carbonizing the 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 producing a catalyst for an aquatic reforming reaction according to the present invention, Step 4 is a step of preparing a mesoporous carbon support by removing the template of Step 3 above. Specifically, removal of the template may be performed by, for example, a method of etching silica with HF or NaOH aqueous solution.

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

Specifically, the catalytically active metal in Step 6 may be selected from Group VIIB transition metals and Group VIII transition metals. 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.

The impregnation of step 5 may be carried out by an impregnation method commonly used in the art, but the incipient wetness method is preferred because uniform dispersion is possible 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 for an aquatic reforming reaction produced by the production method according to the present invention has mesoporous carbon having a high surface area, regular pore structure and uniform mesopores as a support, and the shape of the carbon support particles is 3 Dimensional elliptical or spherical shape, and the average particle size of the carbon support is a relatively constant nano size in the range of 300-600 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. In order to produce hydrogen from oxygen hydrocarbons It can be used more advantageously in an aqueous 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 hydrogen conversion rate, yield and hydrogen production rate can be remarkably improved.

The present invention also provides a process for preparing a catalyst for an aquatic reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon according to the present invention, which comprises the steps of: preparing a mesoporous silica template of nano size for preparing a carbon- Since the dry-gel (DGC) method is applied instead of using an additive and a dispersant, it is possible to solve problems of environmental problems, solvent volatilization and particle irregularity due to the use of conventional solvents, Since the carbon carrier prepared therefrom has a three-dimensional ellipsoidal shape or spherical shape and has an average particle size of 300-600 nm and a relatively constant size, when the aqueous reforming reaction is carried out using a catalyst impregnated with an active metal, Is further improved and the hydrogen selectivity and the hydrogen production rate are further 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> Dry gel  By law Mesoporous DGC -Nano- CMK3 Carbon support  catalyst

Manufacturing example  One:

Dry gel  By method Nano-sized Mesoporous SBA -15 Preparation of silica mold

FIG. 1 shows a method of preparing a nanoscale mesoporous SBA-15 silica mold by a dry-gel method according to an embodiment of the present invention.

First, 2.0 g of EO ₂₀ PO ₇₀ EO ₂₀ (trade name: Pluronic P ₁₂₃ , EO: ethylene glycol, PO: propylene glycol) as a triple block copolymer and 14.6 g of 37.2 wt% hydrochloric acid (HCl) were mixed in 60.2 g of water, For 1 hour. Next, when Pluronic P ₁₂₃ is completely dissolved, 4.5 g of silica, tetraethyl orthosilicate (TEOS) is added, and the mixture is stirred at the same temperature for 2 minutes. Next, when the mixed solution becomes an emulsion form, it is aged for about 2 hours and filtered.

Next, the preparation step is carried out by a dry-gel method. Specifically, the structural derivative / silica composite is placed in an oven and heated at 55 ° C for 3 hours to dry the water to maintain the solid state , Pulverized into powder form, and subjected to hydrothermal synthesis using a high-pressure hydrothermal reactor. That is, an internal vessel into which the above-described structural derivative / silica composite powder was injected was placed in a high-pressure reactor, distilled water corresponding to about 10 times the weight of the powder was injected into the high pressure reactor, and the lid of the high pressure reactor was closed and fixed. For 24 hours. That is, a drying gel is formed by a method in which water in the high-pressure hydrothermal reactor is evaporated and the hydrothermal synthesis is performed by contacting the solid content of the inner vessel. Subsequently, the reactor was disassembled to remove the internal wet solid components, followed by drying and firing to remove the structural derivative, thereby preparing a nano-sized SBA-15 silica mold.

Manufacturing example  2:

Nano-sized Mesoporous Aluminosilicate Al - SBA Manufacture of -15

Next, 0.111 g (Si / Al = 20) of AlCl ₃ per 1 g of the SBA-15 silica mold of Preparation Example 1 was added to ethanol (20 g) in order to make a nano-sized mesoporous Al- Was mixed and stirred well for about 30 minutes. Ethanol was evaporated off, dried, and then calcined at 550 ° C for 5 hours to prepare nano-sized mesoporous aluminosilicate Al-SBA-15.

Manufacturing example  3:

Nano-sized Mesoporous DGC -Nano- CMK3 Carbon support  Produce

Next, 8.5 g of furfuryl alcohol was impregnated stepwise in 10 g of Al-SBA-15 of Production Example 2, spread at 35 ° C for 1 hour, heated to 100 ° C and dried for 1 hour And then maintained at 350 DEG C for 3 hours to carry out initial carbonization. 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 a nano-sized DGC-nano-CMK3 carrier.

Manufacturing example  4:

Platinum bearing Nano-sized Mesoporous DGC -Nano- CMK3 Carbon support  Preparation of Catalyst

First, 0.185 g of Hexachloro platinic acid (H ₂ PtCl ₆ ) as a precursor of platinum was mixed with 3.0 ml of acetone to prepare a homogeneous solution. Then, using the initial wetting method, the prepared nanosized mesoporous The CMK3 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 / DGC-nano-CMK3.

< Example  2> Dry gel  By law Mesoporous DGC -Nano- CMK5 Carbon support  catalyst

Manufacturing example  One:

Dry gel  By method Nano-sized Mesoporous SBA -15 Preparation of silica mold

A mesoporous mesoporous SBA-15 silica template 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, a nano-sized mesoporous SBA-15 silica template was prepared in the same manner as in Preparation Example 2 of Example 1.

Manufacturing example  3: Nano-sized Mesoporous DGC -Nano- CMK5 Carbon support  Produce

Next, the same procedure as in Production Example 3 of Example 1 was carried out, except that the process of impregnating the mesoporous silica / carbon composite with furfuryl alcohol was not performed in Production Example 3 of Example 1, Mesoporous DGC-nano-CMK5 carbon support.

Manufacturing example  4:

Platinum bearing Nano-sized Mesoporous DGC -Nano- CMK5 Carbon support  Preparation of Catalyst

Next, a catalyst impregnated with platinum in a nano-sized mesoporous CMK5 carbon support was prepared in the same manner as in Preparation Example 4 of Example 1, and the catalyst thus prepared was replaced with 7 wt% Pt / DGC-nano-CMK5 Respectively.

< Comparative Example  1> Mesoporous  Micro- CMK3 Carbon support  catalyst

The same procedure as in Example 1 was carried out except that the drying gel preparation step was not carried out in Production Example 1 of Example 1 and drying (100 ° C, 24 hours) and firing (550 ° C, 5 hours) A micro-sized CMK3 carbon support catalyst was prepared and the prepared catalyst was named 7 wt% Pt / Micro-CMK3.

< Comparative Example  2> Mesoporous  Micro- CMK5 Carbon support  catalyst

A method similar to that of Example 2 was carried out except that the drying gel preparation step was not carried out in Production Example 1 of Example 2 and the drying was immediately carried out (100 ° C., 24 hours) and firing (550 ° C., 5 hours) A microparticle size CMK5 carbon support catalyst was prepared and the catalyst was named 7 wt% Pt / Micro-CMK5.

< Experimental Example  1> catalyst Carrier  Property evaluation

The nanoparticle sized mesoporous DGC-nano-CMK3 and DGC-nano-CMK5 carbon supports prepared by the dry gel method of Example 1-2 of the present invention and the micro sized mesoporous micro- In order to evaluate the physical properties of the CMK3 and micro-CMK5 carbon carriers, field emission scanning electron microscope (SEM) photographs of the carbon carriers are shown in Fig. 2, nitrogen adsorption / desorption isotherms are shown in Fig. 4, XRD diffraction results Respectively. 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 Average particle size
(탆) 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-CMK3 3.0 1124 1.10 3.8 Comparative Example 2:
Micro-CMK5 3.0 1630 1.49 3.2, 4.4 Nano SBA-15 - 412 0.90 10.9 Example 1:
DGC-Nano-CMK3 0.5 1,064 1.10 3.7 Example 2:
DGC-Nano-CMK5 0.5 1,857 1.80 3.0, 4.1

As a result, referring to the field emission scanning electron microscope photograph of FIG. 1, the average particle size of the nano-sized mesoporous CMK3 and CMK5 carbon supports of Example 1 - 2 according to the present invention was 300 to 600 nm, Can be confirmed to have a three-dimensional elliptical or spherical shape.

Further, the pore volume and pore size of the nano-sized mesoporous DGC-nano-CMK3 and DGC-nano-CMK5 carbon supports according to the embodiments of the present invention are determined by micro-size micro-CMK3 and micro- CMK5 carbon support was higher than that of CMK5.

In the comparative example not subjected to the drying gel process, the micro-CMK5 had double pores having a size of 3.2 and 4.4 nn, whereas in the case of the dried gel process, DGC-nano-CMK5 had double pores having sizes of 3.0 and 4.1 nm .

This is because the furfuryl alcohol used as the carbon precursor has a property of being coated on the hydrophilic silica wall during the polymerization at a low temperature, and the water, carbon dioxide, and oxygen generated in the polymerization and carbonization process during the carbonization under vacuum, The carbon skeleton is made into a tubular type because by-products such as carbon monoxide, methane and saturated carbons having a low carbon number are effectively removed from the center of the silica pores. Therefore, after the hydrofluoric acid treatment, the carbon pores have pores between the tube and the tube and pores of the tube itself, so that mesoporous carbon having two mesopores is obtained. On the other hand, in the case of CMK3, a carbon precursor is polymerized and carbonized once to about 350 ° C., and then a carbon precursor is added once more to fill the exiting portion. Thus, a rod-shaped carbon skeleton is formed, After the treatment, the carbon pores show only one pore between the bars.

< 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 GC-TCD equipped with a carboxen 1000 packed column and a GS-GASPRO capillary column using nitrogen as an internal standard and 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 / DGC-nano-CMK3 84.3 76.4 52.4 Example 2 7 wt% Pt / DGC-nano-CMK5 82.0 83.1 53.3 Comparative Example 1 7 wt% Pt / micro-CMK3 70.4 72.6 45.1 Comparative Example 2 7 wt% Pt / micro-CMK5 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 / DGC-nano-CMK3 62.2 55.4 42.1 Example 2 7 wt% Pt / DGC-nano-CMK5 68.5 52.1 46.7 Comparative Example 1 7 wt% Pt / micro-CMK3 47.8 38.1 27.1 Comparative Example 2 7 wt% Pt / micro-CMK5 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, in the case of the nano-sized mesoporous DGC-nano-CMK3 and DGC-nano-CMK5 carbon support catalysts of Examples 1 and 2 according to the present invention, a comparative micro-sized carbon- And Comparative Example 2, the conversion rate of hydrogen gas, the yield of hydrogen, and the production rate of hydrogen are 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.

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.

The present invention also provides a process for preparing a catalyst for an aquatic reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon according to the present invention, in order to prepare a nanoscale mesoporous silica template for producing a carbon carrier by a template synthesis method, Since the dry-gel (DGC) method is applied instead of using an additive and a dispersant, problems of environmental problems, solvent volatilization and particle irregularity due to the use of conventional solvents can be solved, Can be more usefully used as a method for producing a catalyst for reaction.

Claims (10)

Characterized in that a catalytically active metal is carried on a regular mesoporous carbon carrier, the shape of the carbon carrier is a three-dimensional ellipsoidal or spherical shape, and an average particle size is 300 to 600 nm. For producing hydrogen from hydrogen.
The method according to claim 1,
Wherein the mesoporous carbon support has an average pore size of 2 - 10 nm.
The method according to claim 1,
Wherein the mesoporous carbon support has an average pore volume of 1.0 - 2.5 cm &lt; ³ &gt; / g.
The method according to claim 1,
Wherein the content of the catalytically active metal is 1 to 10 parts by weight based on 100 parts by weight of the carbon support.
The method according to claim 1,
Wherein the catalytically active metal is one selected from the group consisting of a transition metal of group VIIB and a transition metal of group VIII and the oxygen-containing hydrocarbon is selected from the group consisting of ethylene glycol, glycerol, propylene glycol, sorbitol, sucrose, sugar, sugar alcohol and xylitol Lt; RTI ID = 0.0 &gt; 1, &lt; / RTI &gt;
Preparing a mesoporous silica mold having a three-dimensional elliptical or spherical shape with an average particle size of 300 to 600 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 mold of step 3 to produce a mesoporous carbon support (step 4); And
Impregnating the mesoporous carbon support of step 4 with a catalytically active metal (step 5)
The step of preparing the mesoporous silica mold of the three-dimensional elliptic or spherical shape having the average particle size of 300 to 600 nm in the step 1,
Preparing a structural derivative for a silica template from a mixed solution of a copolymerized organic solvent, hydrochloric acid and water (step a);
Adding a silica precursor to the mixed solution of step a) to form a structural derivative / silica complex (step b);
Drying the composite of step b), pulverizing and pulverizing (step c);
Hydrothermally synthesizing the powder of step c by contacting it with water vapor (step d); And
(D) drying and then firing the hydrothermally synthesized solid component of step (d) to remove the structural derivative (step d).
delete [7] The method of claim 6, wherein the hydrothermal synthesis of step d) is performed at a temperature of 100 to 150 ° C for 1 to 72 hours.
A catalyst for an aqueous reforming reaction for producing hydrogen from an oxygen-containing hydrocarbon produced by the production method of claim 6.
A process for the production of hydrogen via an aquatic reforming reaction from an oxygen-containing hydrocarbon comprising the step of contacting the catalyst for aqueous phase reforming according to claim 1 or 9 with an oxygen-containing hydrocarbon.

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