KR20150111183A - Metal foam catalyst for fuel reforming and fuel reforming apparatus having microchannels - Google Patents

Abstract

The present invention provides a catalyst for reforming fuel, comprising: a metal foam; and a catalyst layer consisting of a composite of at least one precious metal formed on the metal foam, and selected from the group consisting of palladium (Pd), rhodium (Rh), and platinum (Pt), and at least one oxide selected from the group consisting of zirconium oxide (ZrO_2), aluminum oxide (Al_2O_3), and cerium oxide (CeO_2). Accordingly, the catalyst for reforming fuel, having specifically improved catalyst activity and stability for an SMR reaction is provided, thereby significantly improving efficiency of a fuel reforming reaction, and preventing decrease in catalyst activity by allowing the metal foam of the catalyst for reforming fuel to effectively support a precious metal-oxide catalyst layer. A fuel reformer having a microchannel structure, including the catalyst for reforming fuel, does not need to increase an S/C ratio of a flow of a hydrocarbon source gas-steam mixture to a level required in a conventional fuel reformer since a plasticity phenomenon of precious metal particles which are applied as an active material of a catalyst, and tendency that a solid carbon material generated in a process of reforming hydrocarbon source gas is deposited on a surface of a catalyst, and catalyst activity is deteriorated are specifically decreased.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a fuel reforming catalyst in the form of a metal foam, and a microchannel structure reforming apparatus having the catalyst,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst that can be used in a fuel reformer that reforms hydrocarbons to supply synthesis gas or hydrogen and a microchannel structure fuel reformer having the catalyst. More particularly, the present invention relates to a fuel reformer using a metal foam having a large surface area per unit volume The present invention relates to a fuel reforming catalyst that greatly increases the efficiency of fuel reforming and a microchannel structure fuel reformer provided with the catalyst.

Fuel cells are energy conversion devices that convert chemical energy of fuel directly into electrical energy by electrochemical reaction. In particular, solid oxide fuel cells (SOFCs) use solid oxides as electrolytes and operate at high temperatures. . As a fuel commonly used for fuel cells, there is hydrogen which is obtained by reacting a hydrocarbon raw material with an oxidizing agent or steam in a fuel reformer. The most commercially used hydrogen production method is to react methane (CH ₄ ) with water vapor in the presence of a catalyst Is steam-methane reforming (SMR) which converts hydrogen (H ₂ ), carbon monoxide (CO), and carbon dioxide (CO ₂ ).

[Reaction Scheme 1]

CH ₄ + H ₂ ? 3H ₂ + CO; ? H ^? = 206.1 kJ / mol

The conversion rate required in the SMR reaction can be obtained when the temperature reaches 1073 K in the reaction scheme 1. However, a catalyst having high activity and selectivity is required to obtain a conversion rate that meets commercial process standards at such high temperatures. However, the catalyst used in the SMR reaction has a problem in that the catalyst is inactivated by the deposition of the solid carbon material (coke) on the surface of the catalyst at such high temperature operating conditions.

Korean Patent Laid-Open Publication No. 10-2004-019273 discloses a catalyst comprising a metal support, a crystalline silicate and silica, an adhesive layer formed on the metal support, and a catalyst layer formed on the adhesive layer, Discloses a method for increasing adhesion by interposing an adhesive layer therebetween in order to increase the adhesion between them.

However, the above-described invention only increases the adhesion between the metal support and the catalyst layer, and does not disclose any control of the removal of carbon deposited on the catalyst surface and the formation of inactive metal oxides and undesired reactions with oxides.

On the other hand, the fuel reformer used in the solid oxide fuel cell generally has a heat exchange type catalytic combustion section configured to repeatedly cross the heat exchange section and the catalytic combustion section in layers. The waste heat of the solid oxide fuel cell and the heat of combustion And a steam generator for generating steam by using the steam generator. According to Korean Patent Laid-Open Publication No. 10-2006-0135378, a reforming reaction unit for reforming a hydrogen-containing fuel to generate hydrogen floating gas is provided. The reforming reaction unit effectively removes the CO gas without degrading the activity of the CO removal catalyst, The present invention has been made to solve the above-mentioned problems. However, the present invention has been made in view of the above-mentioned problems, and it is also an object of the present invention to provide a fuel cell system capable of supplying a catalytic activity to a fuel cell system by forming a catalyst layer composed of a complex of a metal and an oxide using a metal foam as a support, There is still a need for a catalyst for a fuel reformer that increases the activity of a catalyst layer formed on a metal foam and a microchannel structure fuel reformer for increasing hydrogen production using the same.

A catalyst for a fuel reformer having excellent activity and stability is prepared by supporting a catalyst layer containing a noble metal and an oxide on a metal foam having a large surface area per unit volume. The catalyst is inserted into an integrated reactor equipped with a microchannel, The present invention provides a fuel reformer having a microchannel structure capable of reforming a fuel cell.

The present invention relates to a metal foam; And is formed on the metal foam, palladium (Pd), rhodium (Rh) and platinum (Pt) group of one or more noble metal and the zirconium oxide selected from the consisting of (ZrO _2), aluminum oxide (Al ₂ O ₃₎ and cerium oxide a fuel reforming catalyst comprising a catalyst bed consisting of one or more oxides selected from the group consisting of (CeO _2).

Further, the catalyst layer may contain 1.00 to 3.00 wt% of noble metal and 97 to 99 wt% of oxide.

The noble metal may be mixed in a weight ratio of palladium: rhodium of 7: 1 to 3: 1 by weight.

The noble metal may be used as a combustion catalyst by mixing platinum: palladium in a weight ratio of 2: 1 to 1: 2 by weight.

The metal foam may be made of an alloy of iron (Fe), aluminum (Al), nickel (Ni), and chromium (Cr).

The metal foam may have a pore size of 400 to 450 탆.

According to another aspect of the present invention, there is provided a method of manufacturing a metal foam, Coating the metal foam with a binder; Washing coating the noble metal and the oxide on the coated metal foam; And a step of firing the washcoated metal foam to remove the binder. The present invention also provides a method for manufacturing a catalyst for reforming a fuel using a metal foam.

According to another aspect of the present invention, there is provided a gas reforming apparatus comprising: a gas reforming unit having a raw material gas inlet through which hydrocarbon raw material gas and water vapor (H ₂ O) are introduced into one side and a reformed gas discharge port through which the reformed gas is discharged to the other side; The stacked flue gas is combusted to form a flue gas outlet through which the stacked flue gas of the solid oxide fuel cell is introduced into one side and the combustion gas outlet is formed on the other side, A structural fuel reformer, comprising: a gas reforming unit having a strip-shaped catalyst for fuel reforming containing palladium and rhodium on the inside thereof, a reforming unit for reforming the reformed gas by introducing the raw material gas, And a combustion catalyst containing platinum and palladium on the inner side thereof is provided in the shape of a strip, the stacked flue gas is introduced and combusted by the combustion catalyst, the generated heat is transferred to the gas reforming unit, And a combustion section for exhausting the stacked flue gas.

The raw material gas and the stacked flue gas flow in opposite directions so that good heat exchange occurs between the flow of the raw material gas flowing into the gas reforming section and the flow of the stacked flue gas flowing into the combustion section and the gas reforming section and the combustion section are connected to each other They can be arranged in an intersecting manner.

Wherein the gas reforming section and the combustion section have microchannels of a narrow rectangular cross-section having a gap of 1.5 mm to 2.0 mm, wherein the reforming catalyst provided inside the gas reforming section and the combustion catalyst provided inside the combustion section are respectively opposed to each other Are inserted at opposite sides of the catalyst, and one end of these catalysts can be arranged so that they partially overlap each other in the longitudinal direction.

According to the catalyst for reforming fuel according to the present invention, the efficiency of the reforming reaction can be greatly increased by providing a catalyst for reforming fuel with improved activity and stability against SMR reaction, and the metal foam of the fuel reforming catalyst can support the noble metal catalyst layer Thereby preventing the reduction of the activity of the catalyst.

In the microchannel structure fuel reformer having the catalyst for reforming fuel, the noble metal particles used as the active material are sintered, or the solid carbon material (coke) generated in the course of modifying the hydrocarbon gas is deposited on the catalyst, There is an advantage that it is not necessary to maintain the high S / C ratio (steam to carbon ratio) required in conventional fuel reformers.

FIG. 1A is a schematic view showing a configuration of a tubular reaction device for measuring the efficiency of a fuel reforming catalyst according to an embodiment of the present invention. FIG.
1B is a schematic view showing a configuration of a microchannel structure fuel reformer according to an embodiment of the present invention.
2A is a graph showing the conversion of methane to methane according to the temperature of an SMR reaction at a GHSV of 8500 / h of a catalyst for reforming palladium-rhodium containing fuel according to an embodiment of the present invention.
FIG. 2B is a graph showing the conversion of methane to the raw material gas S / C ratio of the SMR reaction at a GHSV of 8500 / h of the catalyst for reforming palladium-rhodium containing fuel according to an embodiment of the present invention.
FIG. 2C is a graph showing the selectivity of hydrogen / carbon monoxide according to the raw material gas S / C ratio of the SMR reaction at a GHSV of 8500 / h of the palladium-rhodium-containing fuel reforming catalyst according to an embodiment of the present invention.
2d is a graph showing the selectivity of carbon monoxide / (carbon monoxide + carbon dioxide) according to the S / C ratio of the raw material gas in the SMR reaction at a GHSV of 8500 / h of the palladium-rhodium containing fuel reforming catalyst according to an embodiment of the present invention .
FIG. 3A is a graph of the catalyst stability as a trend of methane conversion rate with respect to the reaction time of the SMR reaction at GHSV 8500 / h of the catalyst for modifying palladium-rhodium containing fuel according to an embodiment of the present invention.
FIG. 3B is a graph of catalyst stability, which shows the selectivity trend of hydrogen / carbon monoxide according to the reaction time of the SMR reaction at GHSV 8500 / h of the catalyst for the modification of palladium-rhodium containing fuel according to an embodiment of the present invention.
FIG. 3C is a graph of catalyst stability as a selectivity trend of carbon monoxide / (carbon monoxide + carbon dioxide) with respect to the reaction time of the SMR reaction at a GHSV of 8500 / h of the palladium-rhodium containing fuel reforming catalyst according to an embodiment of the present invention.
FIG. 4A is a graph showing a conversion rate of methane according to the temperature of a palladium-rhodium-containing fuel reforming catalyst and a conventional reforming catalyst according to an embodiment of the present invention. FIG.
FIG. 4B is a graph showing the selectivity of hydrogen / carbon monoxide according to the temperature of the palladium-rhodium-containing fuel reforming catalyst and the commercial reforming catalyst according to an embodiment of the present invention.
FIG. 4c is a graph showing the selectivity of carbon monoxide / (carbon monoxide + carbon dioxide) according to the temperature of the palladium-rhodium-containing fuel reforming catalyst and the commercial reforming catalyst according to an embodiment of the present invention.
5A is a graph showing the conversion rate of methane according to reaction time of a catalyst for reforming palladium-rhodium containing fuel and a commercial reforming catalyst at 1023 K, GHSV 2000 / h according to an embodiment of the present invention.
FIG. 5B is a graph showing the selectivity of hydrogen / carbon monoxide depending on the reaction time of the palladium-rhodium-containing fuel reforming catalyst and the commercial reforming catalyst at 1023 K, GHSV 2000 / h according to an embodiment of the present invention.
5c is a graph showing the selectivity of carbon monoxide / (carbon monoxide + carbon dioxide) according to the reaction time of the catalyst for reforming palladium-rhodium containing fuel and the commercial reforming catalyst at 1023 K, GHSV 2000 / h according to an embodiment of the present invention .
FIG. 6 is a graph showing the composition of a reformed gas according to the temperature of the SMR reaction at a feed gas S / C ratio of 2.5 and a GHSV 2000 / h of a palladium-rhodium containing fuel reforming catalyst according to an embodiment of the present invention.
7A is a graph showing the conversion efficiency of SMR according to the temperature of a microchannel structure fuel reformer equipped with a catalyst for reforming palladium-rhodium containing fuel according to another embodiment of the present invention, in terms of conversion rate of methane.
FIG. 7B is a graph showing the combustion efficiency of the stacked flue gas of the solid oxide fuel cell according to the temperature of the microchannel-structured fuel reformer provided with the platinum-palladium-containing combustion catalyst according to another embodiment of the present invention, by the conversion rate of methane.
FIG. 8A is a graph illustrating a trend of a catalyst bed temperature in a microchannel-structured fuel reformer equipped with the fuel reforming catalysts according to another embodiment of the present invention. FIG.
FIG. 8B is a graph showing changes in the catalyst bed temperature trend with increasing GHSV in a microchannel structure fuel reformer equipped with the fuel reforming catalysts according to another embodiment of the present invention. FIG.
9 is an electron micrograph (SEM) image of a catalyst for reforming fuel according to an embodiment of the present invention.
10 is an electron transmission microscope (TEM) image of a fuel reforming catalyst according to an embodiment of the present invention.

The present inventors have been trying to increase the activity and stability of the catalyst for steam-methane fuel reforming. In the washcoat of a noble metal-oxide complex on a metal foam having a large surface area per unit volume, And it is confirmed that the activity and stability of the catalyst are maintained at a low operating temperature while the ratio of S / C (steam to carbon ratio) of the raw material gas is required to be low. Thus, the catalyst for fuel reforming of the present invention is completed.

In addition, the manufactured fuel reforming catalyst was mounted on a micro-channel fuel reformer to complete a microchannel structure fuel reformer having excellent fuel reforming efficiency of SMR (steam-methane reforming; SMR) reaction and excellent catalytic activity and stability .

Hereinafter, the present invention will be described in detail.

The catalyst for reforming fuel of the present invention comprises a metal foam and at least one noble metal selected from the group consisting of palladium (Pd), rhodium (Rh) and platinum (Pt), zirconium oxide (ZrO ₂ ) And a catalyst layer made of at least one oxide selected from the group consisting of aluminum oxide (Al ₂ O ₃ ) and cerium oxide (CeO ₂ ).

A major cause for lowering the stability of the catalyst in the SMR reaction is that the solid carbon material adsorbs on the surface of the catalyst to deactivate the catalyst. The catalyst is fired in the SMR reaction process and is inactivated by the formation of an inert metal compound or an unavoidable reaction with an oxide support.

Metal foams are usefully used as heat transfer media, such as catalyst supports, and are also used as non-catalytic filters to reduce emissions. The specific hydrodynamic and mechanical properties as well as the structural properties of the metal foams required as a catalyst support are the differentiated properties of metal foams that can be characterized in heterogeneous phase catalysis. The gas permeability of metal foams serves to allow the reaction gas to more readily adsorb to the active sites of the catalyst. In addition, the metal foam has a small heat capacity, excellent heat transfer ability, and can be molded into a desired shape. The interconnected cavities of the metal foams can be a useful pathway for gas phase flow and provide a catalyst having good metal dispersion, good surface area and pore volume, light weight and small density when the catalyst layer is wash coated on the metal foams Can be manufactured.

The catalyst layer is made of a noble metal and an oxide.

Precious metals can replace conventional nickel or ruthenium and exhibit excellent hydrogen selectivity and methane reforming capability at low temperatures and low S / C ratios.

The rhodium (Rh) was selected as the most active noble metal in the SMR reaction, and the surface of the catalyst was modified by adding palladium (Pd) as the second noble metal to increase the dispersion of the metal particles And the carbon deposition on the catalyst surface was reduced.

The catalyst layer may contain 1.00 to 3.00 wt% of noble metal and 97 to 99 wt% of oxide. When the weight percentage range of the noble metal is out of the above range, the catalyst production cost increases, and when the weight percentage range of the oxide is out of the above range, the optimum catalyst layer made of noble metal and oxide is not formed.

The noble metal may be mixed with palladium and rhodium at a weight ratio of 7: 1, and palladium and rhodium may be mixed at a weight ratio of 3: 1.

When palladium and rhodium are mixed in the catalyst layer, they are used in the SMR reaction. The oxide of the noble metal may be mixed with aluminum oxide: zirconium oxide in a weight ratio of 65:35.

In the case of the fuel reforming catalyst used in the SMR reaction, it is preferable to produce a composite in which the catalyst layer contains 1.31 wt% of noble metal and 98.69 wt% of oxide.

Also, platinum and palladium may be mixed in a catalyst layer at a weight ratio of 2: 1 and used as a combustion catalyst. In this case, it is preferable that the oxide is mixed with aluminum oxide: zirconium oxide in a weight ratio of 95: 5 to the noble metal, and the noble metal is contained in the catalyst layer in an amount of 1.31% by weight.

The catalyst is preferably prepared by wash coating a total of 76 grams of noble metal-oxide complex per liter of metal foam. The metal foam is an alloy of iron (Fe), aluminum (Al), nickel (Ni), and chromium (Cr), and may have a density of 1.2 to 1.6 g / cm < 3 >.

The metal foam may be coated with the binder solution before wash coating the noble metal-oxide composite.

The metal foam may have a pore size of 400 to 450 탆.

According to another aspect of the present invention, there is provided a method of manufacturing a metal foam, Coating the metal foam with a binder; Wash coating the noble metal-oxide composite on the coated metal foam; And calcining the washcoated metal foam to remove the binder. The present invention also provides a method for manufacturing a catalyst for a fuel reformer using the metal foam.

The metal foam may be pretreated with distilled water and acetone and may be dried at a temperature of 398 to 423 K for 1 to 2 hours before wash coating.

The step of calcining the washcoated metal foam may be performed at a temperature lower than 1200 K for 3 to 5 hours. If the condition is exceeded, the binder may not be removed from the metal foam but the washcoat may be damaged.

According to another aspect of the present invention, there is provided a gas reforming apparatus comprising: a gas reforming unit having a raw material gas inlet through which hydrocarbon raw material gas and water vapor (H ₂ O) are introduced into one side and a reformed gas discharge port through which the reformed gas is discharged to the other side; And a combustion section in which a combustion gas inlet is formed at one side of the solid oxide fuel cell and a waste gas outlet at which the stacked flue gas is combusted is formed at the other side, A channel structure fuel reformer, comprising: a gas reforming unit having a strip-shaped catalyst for fuel reforming containing palladium and rhodium on the inner side, reforming the reformed gas with a fuel reforming catalyst by introducing the raw gas; And a combustion catalyst containing platinum and palladium on the inner side is provided in a strip shape, and the stacked flue gas is combusted by a combustion catalyst, the generated heat is transferred to the gas reforming unit, and the combusted stack flue gas And a combustion section for exhausting the fuel.

The type of reactor used in the SMR reaction can affect the reaction efficiency, and in the SMR reaction for producing the fuel used in the small-scale solid oxide fuel cell, the microreactor or microchannel structure reactor is a tubular reactor, Can be configured to be much smaller.

The choice of reactor is determined by various conditions, such as mass transfer and heat transfer, pressure drop, space constraints, the use of a concentric tubular reactor integrated with a heat exchanger, and in the present invention the microchannel structure reactor can reduce the energy supply of the furnace have. When the microchannel structure is applied to a solid oxide fuel cell (SOFC) by applying to a fuel reformer, the fuel reformer can be miniaturized and the heat exchange function necessary for fuel reforming can be integrated. In the microchannel structure reactor, the endothermic and exothermic reaction zones are integrated to produce efficient reformed gas, and the catalyst may be provided in the form of a thin film into each microchannel in which the reforming reaction and the combustion reaction occur.

The microchannel structure fuel reformer may include a reaction zone defined by a thin channel wall and a zone for inserting a catalyst for a fuel reformer in a strip form.

The microchannel structure fuel reformer has a thin channel wall and a thin catalyst strip, which have a high heat transfer ability in comparison with the shapes of conventional reactors and catalysts, thereby making the fuel reformer more compact.

The gas reforming section and the combustion section may be arranged so that good heat exchange occurs between the flow of the raw material gas flowing into the gas reforming section and the flow of the stacked flue gas of the solid oxide fuel cell flowing into the combustion section.

The gas reforming section and the combustion section are composed of microchannels having a narrow rectangular cross section having a gap of 1.5 to 2.0 mm. The fuel reforming catalyst strip and the combustion catalyst strip, each having a thickness of 1.1 to 1.5 mm, From opposite sides facing each other, and one end of these catalysts can be arranged so that they partially overlap each other in the longitudinal direction.

If the width of the microchannel and the thickness of the catalyst strip are different from each other, the reaction efficiency and thermal efficiency of the fuel reformer may be deteriorated.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

< Example  1> For fuel reforming  Catalyst preparation

A metal foam having a length of 300 mm, a width of 200 mm and a thickness of 1.1 mm was prepared for the preparation of a fuel reforming catalyst containing palladium-rhodium and a combustion catalyst containing platinum-palladium.

(Ni-Al ₂ O ₃ ) catalyst (BASF) was prepared in the form of a pellet having a diameter of 3 mm and a length of 3.3 mm in order to compare with the activity and stability of the reforming catalyst containing palladium- , And a ruthenium-aluminum oxide (Ru-Al ₂ O ₃ ) catalyst (Sud-Chemie) was prepared as spherical particles having a diameter of 3 mm. The fuel reforming catalyst containing palladium-rhodium and the nickel-aluminum oxide and ruthenium-aluminum oxide catalysts were reduced by hydrogen flow at 873 K for 2 hours before the start of the SMR reaction in the reactor, respectively.

A fuel reforming catalyst containing palladium - rhodium and a catalyst for combustion containing platinum - palladium were prepared by wash - coating a composite of noble metal and oxide on a metal foam. The reforming catalyst was prepared by mixing palladium and rhodium at a weight ratio of 7: 1 to prepare a noble metal mixture precursor. The combustion catalyst was prepared by mixing platinum and palladium in a weight ratio of 2: 1 to prepare a noble metal mixture precursor.

The metal foam used as the support was an alloy of iron, aluminum, nickel and chromium, and had a density of 1.4 g / cm 3. A composite composed of a noble metal mixture and an oxide was coated on the metal foam by wash coating and calcined at 1173 K for 4 hours to prepare a catalyst for a fuel reformer.

&Lt; Example 2 > Configuration of microchannel structure fuel reformer

The microchannel structure fuel reformer was constructed by mounting the catalyst for fuel reformer manufactured in Example 1 in a reactor having a microchannel structure.

A fuel reforming catalyst containing palladium and rhodium was used for the SMR reaction for the production of SOFC fuel, and the catalyst for the fuel reforming containing platinum and palladium was used for catalytic combustion of the SOFC stack flue gas as the combustion catalyst.

1B is a schematic view showing a configuration of a microchannel structure fuel reformer according to an embodiment of the present invention.

The microchannel structure fuel reformer was a prototype of a rectangular parallelepiped duct having a length of 292 mm, a width of 42 mm and a height of 38 mm, and the product of CATACEL of USA was used. Nine microchannels with a width of 1.6 mm were placed in the gas reforming section for SMR reaction between methane and water vapor, and correspondingly, nine microchannels with a width of 1.6 mm were used for the combustion reaction of the gas simulating the stack flue gas of the SOFC stack In the combustion zone.

Microchannel structure The structure of the fuel reformer was equipped with an electric furnace and a preheater programmed with temperature control, and a plurality of thermocouples were installed to measure the temperature of the gas reforming part and the combustion part.

The catalyst temperature in the fuel reformer was increased from room temperature to the reaction temperature at the rate of 5 K / min in the flow of the raw gas. The mixed gas flow of methane and water vapor was supplied from a manifold consisting of a gas cylinder, a mixer and a steam generator. The methane flow rate was controlled by a mass flow controller, and the water vapor flow rate was controlled by a micropump.

 Methane and water vapor were mixed and heated in the mixer and steam generator before being introduced into the microchannel structure fuel reformer. To maintain the required GHSV, a fuel reforming catalyst containing palladium-rhodium was prepared in nine strips having a thickness of 1.1 mm, inserted into the gas reforming section, and the corresponding catalyst for platinum-palladium containing combustion was placed in a 1.1 mm thick , And inserted into the combustion section.

In the gas reforming section and the combustion section, the reforming catalyst and the combustion catalyst flow in the direction of flow 124. In the gas reforming section and the combustion section, Mm. &Lt; / RTI &gt;

EXPERIMENTAL EXAMPLE 1 Properties of Catalyst for Fuel Reformer and Analysis of Modified Gas in SMR Reaction

In order to measure the activity and stability of the catalyst in the SMR reaction, SMR reaction was carried out by filling a tubular reactor with a catalyst for fuel reforming containing palladium - rhodium and its performance was compared with that of a commercial catalyst. Microchannel structure The exhaust gas of the fuel reformer was analyzed with a gas chromatograph (GC, DONAM system 6200) equipped with a TCD detector.

Table 1 shows the chemical composition of the catalysts according to an embodiment of the present invention.

[Table 1]

The composition of the metal foam catalyst was measured based on the mass of the catalyst layer after the catalyst layer was formed by wash coating with a composite of noble metal and oxide, and the composition shown in parentheses was the composition based on the total mass of the catalyst for reforming the fuel, it means.

The catalyst specific surface area before and after the reaction was measured by adsorption of nitrogen (N ₂ ) using a gas adsorption method (Quantachrome, ASIC.7; Micromeritics, Gemini 2375). The dispersion of noble metal particles in the catalyst layer was measured by chemical adsorption using a carbon monoxide pulse injected into the helium gas stream at 313 K using a powder sample scraped from the catalyst for fuel reformer (BEL, belcat-m). The pore size distribution and pore volume of the catalyst were determined by desorption of nitrogen (Quantachrome, ASIC.7).

The surface morphology of the fuel reforming catalyst was observed using an electron microscope (FE-SEM, Hitachi Ltd., S-4100, S-4200). The palladium-rhodium catalyst layer supported on the metal foam was observed using a transmission electron microscope (TEM, Hitachi Ltd., H-7600).

Methane conversion and product yields and selectivities were calculated using the molal and molar flows introduced by equations 1 through 4, respectively.

[Formula 1]

× 100Conversion rate (%) =

× 100

[Formula 2]

×100
Hydrogen / carbon monoxide selectivity (H ₂ / CO selectivity) =

× 100

[Formula 3]

× 100CO Selectivity =

× 100

[Formula 4]

× 100
The hydrogen yield per unit mole of incoming methane (H ₂ yield per unit mole CH ₄ input) =

× 100

1. Performance analysis of reforming catalyst by experimental data of tubular reactor

In order to confirm the performance of SMR reaction of a fuel reforming catalyst containing palladium-rhodium, a tubular reactor was filled with a fuel reforming catalyst to select the products according to various S / C ratios between steam and raw gas, The stability was measured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a schematic view showing the configuration of a tubular reactor apparatus used for measuring the performance of a fuel reforming catalyst according to an embodiment of the present invention; FIG.

Referring to the drawings, a tubular reactor (SUS 304, diameter 20 mm, length 330 mm) was equipped with a K-type thermocouple to measure the temperature of the electrically charged electric furnace and the catalyst charging area.

FIG. 2A is a graph showing a conversion rate of methane according to temperature in an SMR reaction at a GHSV of 8500 / h of a palladium-rhodium-containing reforming catalyst according to an embodiment of the present invention. FIG. FIG. 2C is a graph showing the conversion rate of methane according to the S / C ratio in the GHSV 8500 / h of the palladium-rhodium-containing reforming catalyst according to one embodiment of the present invention. FIG. 2 (d) is a graph showing the selectivity of hydrogen / carbon monoxide according to the S / C ratio according to the S / C ratio in the case of the palladium-rhodium containing reforming catalyst according to the embodiment of the present invention. As shown in Fig.

Referring to the drawings, the GHSV was fixed at 8500 / h, and the S / C ratio was changed from 2.5 to 3.5, and the conversion rate of methane was measured. The SMR reaction started near 600 K, when the methane call was almost complete, the temperature reached 1050 K.

2A and 2B, the conversion rate of methane was influenced by the S / C ratio at a temperature of 950 K or less, but it was independent of the S / C ratio when it exceeded 950 K.

In FIG. 2C, the hydrogen / carbon monoxide selectivity decreased with temperature, but increased with the S / C ratio. On the other hand, in FIG. 2d, the selectivity of carbon monoxide decreased with the temperature and decreased with the S / C ratio.

The methane conversion rate and the carbon monoxide selectivity of the reforming catalyst were significantly increased as compared with the conventional Rh-perovskite catalyst of 5 wt%, and the reforming catalyst used in the present invention was palladium Rhodium was contained only in the catalyst layer at only 1.31 wt%.

FIG. 3A is a graph showing the catalyst stability according to the SMR reaction time at a GHSV of 8500 / h of a palladium-rhodium-containing reforming catalyst according to an embodiment of the present invention, in terms of methane conversion rate, and FIG. FIG. 3C is a graph showing catalyst stability according to SMR reaction time at GHSV 8500 / h of the palladium-rhodium-containing reforming catalyst according to the embodiment of the present invention. FIG. 8500 / h showing the catalyst stability according to the SMR reaction time in terms of carbon monoxide selection.

When the SMR reaction was carried out at 1073 K for 48 hours at a GHSV of 8500 / h, the palladium-rhodium-containing reforming catalyst showed a high stability in the SMR reaction, and the S / C ratio was 2.5 To 3.5 showed no significant effect on the catalyst stability.

(Ni-Al ₂ O ₃ ) catalyst (BASF) and ruthenium-aluminum oxide (Ru-Al ₂ O ₃ ) catalyst (Sud-Chemie) prepared as described above were compared with each other Catalyst activity, product selectivity and catalyst stability were measured. The operation conditions of the tubular reactor filled with the catalyst were GHSV 8500 / h and S / C ratio was 2.5.

 FIG. 4A is a graph showing the conversion of methane to methanol according to the reaction temperature between the catalyst for reforming palladium-rhodium and the catalyst according to an embodiment of the present invention. FIG. FIG. 4C is a graph showing the selectivity of hydrogen / carbon monoxide according to the reaction temperature between the catalyst and the commercial catalyst, FIG. 4C is a graph showing the selectivity of carbon monoxide according to the reaction temperature of the palladium- Fig.

Referring to FIG. 4A, the methane conversion rate was measured for all the catalysts, increasing the reaction temperature from 923K to 1023K. The palladium-rhodium-containing reforming catalyst reached a conversion rate of almost plateau at 1023 K, but the catalysts of nickel-aluminum oxide (Ni-Al ₂ O ₃ ) and ruthenium-aluminum oxide (Ru-Al ₂ O ₃ ) The catalyst reached the same level of conversion as above at the higher temperature of 1073K.

As the reaction temperature increases, in the SMR reaction, CH ₄ + H ₂ O → 3H ₂ + CO reaction, CH ₄ + 2H ₂ O → equilibrium of 4H ₂ + CO ₂ and CH ₄ + CO ₂ → 2H ₂ + 2CO shifts to the right (toward product), resulting in increased production of hydrogen, carbon monoxide and methane conversion.

The catalysts for the reforming of palladium-rhodium-containing fuel showed higher conversion rates of methane from 923 K to 1073 K than nickel-aluminum oxide catalysts and ruthenium-aluminum oxide catalysts, 93.7%, and ruthenium-aluminum oxide catalyst was 94.9%, while that of palladium-rhodium-containing reforming catalyst was as high as 97.2%.

The high activity of the palladium-rhodium-containing fuel reforming catalyst is due to the small particle size of the washcoated catalyst layer and there is no restriction of pore diffusion.

In Figure 4b, the hydrogen / carbon monoxide selectivity of all catalysts tested in the temperature range of 923 K to 1023 K was found to decrease with increasing temperature. The nickel-aluminum oxide catalyst and the ruthenium-aluminum oxide catalyst have a tendency to decrease the selectivity even when the temperature exceeds 1023 K, while the catalyst for the palladium-rhodium-containing fuel reforming has a negligible decrease in the selectivity when the temperature exceeds 1023 K The selectivity tends to decrease continuously.

The hydrogen / carbon monoxide selectivity of the palladium-rhodium-containing reforming catalyst at 1023 K was 5.70, and the selectivities of the nickel-aluminum oxide catalyst and the ruthenium-aluminum oxide catalyst were 5.50 and 6.03, respectively.

According to FIG. 4C, the selectivity of carbon monoxide was increased with temperature in the same temperature range as the hydrogen / carbon monoxide selectivity, and in the case of the catalyst for reforming palladium-rhodium containing fuel, the selectivity of carbon monoxide reached plateau at 1023 K Respectively. At 923 K and 973 K, the carbon monoxide conversion rate by the water gas conversion reaction was smaller than that of the nickel-aluminum oxide catalyst and the ruthenium-aluminum oxide catalyst when the palladium-rhodium-containing reforming catalyst was used. Carbon monoxide was CH ₄ + H ₂ O Which is produced from the reaction of 3H ₂ + CO and CH ₄ + CO ₂ → 2H ₂ + 2CO, while being converted to carbon dioxide at a relatively low temperature by water vapor. Also, at high temperature, it was converted from carbon dioxide to carbon monoxide by the reverse reaction of the water gas conversion reaction.

The selectivity of carbon monoxide at 1073 K was 0.66 for the nickel-aluminum oxide catalyst, 0.64 for the ruthenium-aluminum oxide catalyst, and 0.62 for the palladium-rhodium containing fuel reforming catalyst.

Therefore, the amount of hydrogen produced per mole of methane introduced at 1073 K was 3.16 for the palladium-rhodium-containing reforming catalyst, 2.72 for the nickel-aluminum oxide catalyst and 3.06 for the ruthenium-aluminum oxide catalyst, When the fuel reforming catalyst was used, it was confirmed that the hydrogen production was greatly increased as compared with the commercial catalysts.

 FIG. 5A is a graph showing the methane conversion rate of SMR reaction according to the reaction time of palladium-rhodium-containing reforming catalyst and commercial catalysts at 1023 K, S / C ratio of 2.5 and GHSV 2000 / h according to an embodiment of the present invention, FIG. 5B is a graph showing hydrogen / carbon monoxide selectivity according to the reaction time of a palladium-rhodium-containing reforming catalyst and a commercial catalyst under the reaction conditions according to an embodiment of the present invention. FIG. FIG. 2 is a graph showing carbon monoxide selectivity according to the reaction time of a palladium-rhodium-containing fuel reforming catalyst and a commercial catalyst under the above reaction conditions.

The stability of the tested catalysts was compared for 200 hours under reference conditions of 1023 K, S / C ratio of 2.5 and GHSV 2000 / h. Referring to FIG. 5a, the palladium- rhodium- , Which is higher than the methane conversion of 86.9% and 89.4% of the nickel-aluminum oxide catalyst and the ruthenium-aluminum oxide catalyst, respectively.

FIG. 5B is a graph showing a change in hydrogen / carbon monoxide selectivity with respect to the reaction time. As shown in FIG. 5B, the palladium-rhodium containing reforming catalyst and the nickel-aluminum oxide catalyst showed high values at the initial stage of the reaction, And the ruthenium-aluminum oxide catalyst maintained a steady state from the beginning of the test.

The stabilized hydrogen / carbon monoxide selectivity was 6.3 for the palladium-rhodium containing fuel reforming catalyst, 5.8 for the nickel-aluminum oxide catalyst, and 7.3 for the ruthenium-aluminum oxide catalyst.

According to FIG. 5c, the nickel-aluminum oxide catalyst exhibited transientness at the initial stage of the test for carbon monoxide selectivity. The low selectivity at the beginning of the test was elevated and stabilized after 24 hours. On the other hand, the palladium-rhodium-containing fuel reforming catalyst and the ruthenium-aluminum oxide catalyst showed steady-state carbon monoxide selectivity over the duration of the test.

The selectivity for carbon monoxide stabilization was 0.59 for the palladium-rhodium containing fuel reforming catalyst and 0.52 and 0.62 for the ruthenium-aluminum oxide catalyst and the nickel-aluminum oxide catalyst, respectively.

FIG. 6 is a graph showing the composition of a reformed gas according to an SMR reaction of a palladium-rhodium-containing fuel reforming catalyst according to an embodiment of the present invention, according to a reaction temperature.

The composition of the reformed gas is shown from 923 K to 1023 K on a dry basis under the conditions of GHSV 2000 / h and S / C ratio of 2.5. The composition of methane decreases with increasing temperature, The composition of carbon monoxide increased. At the same temperature range, the composition of CO ₂ was not noticeably changed.

[Reaction Scheme 2]

CH ₄ ↔ C + 2H ₂

The formation of the solid carbon material from the SMR reaction is more favorable under high temperature reaction conditions where the overall conversion of methane is high since Scheme 2 is an endothermic reaction and the formation of solid carbon material due to the dehydrogenation of methane It is known.

[Reaction Scheme 3]

2CO ↔ C + 2CO ₂

CO + H ₂ ↔ C + H ₂ O

CH ₄ + 2CO ↔ 3C + 2H ₂ O

CO ₂ + 2H ₂ ↔ C + 2H ₂ O

Scheme 3 shows the production of a solid carbon material by an exothermic reaction that consumes carbon monoxide or hydrogen and the reaction is known to exhibit a more favorable tendency at low temperature reaction conditions where the overall conversion of methane is low.

As the temperature increases, the equilibrium constant of Equation (2) increases and the equilibrium constant of Equation (3) decreases, so that the overall extent of solid carbon material is determined by the Gibbs free energy change as a function of temperature Lt; / RTI &gt; is determined by the sum of the individual contributions of the reactions corresponding to Scheme 2 and Scheme 3. At low temperatures, solid carbon materials are produced by various reaction paths, whereas at high temperatures, the formation of solid carbon materials by Scheme 2 is prominent and the production of solid carbon materials by Scheme 3 becomes weak.

GHSV 2000 / h, and S / C ratio of 2.5, the total solid carbon material production was estimated at four reaction temperatures. As a result, it was found that the use of palladium-rhodium- The proportions of solid carbon material resulting from the reaction were 6.22%, 16.07%, 12.88% and 7.34% of the methane influx at 923 K, 973 K, 1023 K and 1073 K, respectively.

At 923 K, which is a relatively low methane conversion rate, the formation of solid carbon material according to the reaction formula 2 and the reaction formula 3 was weak. As the reaction temperature increased, the methane conversion rate increased and the reaction of the reaction formula 2 became more advantageous than the reaction of the reaction formula 3 The production of solid carbon material showed a maximum at around 973K to 1023K. At a temperature above 1023 K at which the formation of solid carbon material has exceeded the maximum value, even if Reaction Scheme 2 is advantageous, the amount of methane that can be allocated to such a reaction path is relatively small, and the production of solid carbon material is rather reduced.

Table 2 below shows the specific surface area of the fuel reforming catalyst before and after the SMR reaction. The values in parentheses correspond to the specific surface area of the catalyst layer made of noble metal-oxide complex.

[Table 2]

Samples of palladium-rhodium-containing fuel reforming catalyst, nickel-aluminum oxide catalyst and ruthenium-aluminum oxide catalyst were tested for SMR reaction for 200 hours at 1023 K, S / C ratio of 2.5 and GHSV 2000 / It was used for analysis. The specific surface area of the catalyst after the reaction was reduced by 71% for the nickel-aluminum oxide catalyst and by 30% for the ruthenium-aluminum oxide catalyst compared to the pre-reaction condition, while the catalyst for the palladium- .

The specific surface area measurement data show that the palladium-rhodium-containing catalyst layer supported on the metal foam is more stable than the commercial SMR catalyst due to the influence of zirconium dioxide (ZrO ₂ ), which is a noble metal-oxide composite component in a hydrothermal reaction environment. Furthermore, even if the SMR reaction was continued for 200 hours under the reaction conditions, the activity of the palladium-rhodium-containing fuel reforming catalyst did not decrease at all.

9 is an SEM image of the catalyst for reforming the fuel used in the SMR reaction test according to an embodiment of the present invention. 9 (a) and 9 (b), the nickel-aluminum oxide catalyst clearly showed that the surface was calcined to form partially agglomerated particles. (c) and (d), the firing was confirmed also on the surface of the ruthenium-aluminum oxide catalyst. The change in surface morphology is consistent with the specific surface area reduction of these catalysts.

(e) and (f), the size of the open cavity of the catalyst for the modification of the palladium-rhodium-containing fuel was 400 to 450 탆 before the reaction, and no substantial change in its size was detected after the reaction. (g), (h) and (i), the surface structure of the palladium-rhodium-containing fuel reforming catalyst did not notice any change even after the reaction for the catalyst stability test was carried out. However, as shown in (h), deposition of a solid carbon material such as a spider web was found on the surface corresponding to about 5% of the reforming catalyst after the reaction.

(g) shows the surface before the reaction of the palladium-rhodium-containing reforming catalyst, and (h) shows that about 25% of the catalyst surface after the reaction is covered with the solid carbon material. (i) indicates that solid carbon material is not deposited on the surface of the catalyst after about 75% of the catalyst surface.

The solid carbon material immersed in the surface of the fuel reforming catalyst can be easily removed by exchanging the reactant gas streams flowing through the gas reforming section and the combustion section of the microchannel structure reactor, so that the catalyst for reforming palladium- It is very convenient to apply to.

10 is a TEM image of a catalyst for reforming palladium-rhodium containing fuel according to an embodiment of the present invention. In order to confirm the crystallinity of noble metal particles and the shape of oxides on the metal foam with noble metal and oxide composite formed by wash coating, the surface state was observed using transmission electron microscope.

10, no appreciable change in surface morphology occurred after the reaction for the catalyst stability test. As a result of observation of the degree of dispersion of the noble metal particles, the catalyst for reforming containing palladium-rhodium was dispersed in 38.5% of particles having an average size of 2.6 nm before the reaction, and the dispersion degree was reduced to 30% after 200 hours of the stability evaluation test.

Table 3 below shows the pore size and volume change before and after the reaction of the fuel reforming catalyst used in the evaluation of the catalyst stability. The values in parentheses represent the pore volume per unit mass of the catalyst layer supported on the metal foam.

[Table 3]

In the reaction for the evaluation of the catalyst stability, the average pore size was increased and the average pore volume was reduced, which is consistent with the results of the measurement of the specific surface area and surface morphology.

Compared with the nickel and ruthenium catalyst supported by the aluminum oxide body, the palladium-rhodium-containing fuel reforming catalyst supported on the metal foam had a relatively small pore size and volume change due to the SMR reaction, and the zirconium oxide And contributes to the catalyst stability.

2. Microchannel structure reactor Based on experimental data For fuel reforming  Performance analysis of catalyst

Table 4 shows the composition and flow rates of the simulated gases used for the SMR reaction and the combustion reaction, respectively. The values in parentheses are percentages of the components that make up each simulated gas stream.

[Table 4]

The simulated gases of the SMR reaction were classified into Gas-1a to Gas-2c according to the composition and flow rate of the incoming flow, and the simulated gases of the combustion reaction were classified into Gas-3a, 3b and 3c.

Table 5 below compares the flow rate and composition of the reformed gas stream generated by the SMR reaction by mounting the palladium-rhodium-containing fuel reforming catalyst in a microchannel structure fuel reformer (HEP) and a tubular reactor, respectively. Gas-2c was introduced as a raw material gas, and the SMR reaction was tested under the conditions of GHSV 1200 / h and 983 K, respectively.

[Table 5]

In the case of the HEP reactor, the nitrogen gas was introduced into the combustion section while the SMR reaction occurred in the gas reforming section. Methane conversion rate was 81.5% in the HEP reactor and 82% in the tubular reactor at the reaction temperature. The composition was slightly different. Compared with the results of the tubular reactors, the reformed gas produced in the HEP reactor had a slightly lower fraction of hydrogen and carbon monoxide, and a slightly higher fraction of carbon dioxide. The hydrogen molar amount of the reforming gas produced per unit mole of methane introduced into the reactor was 2.83 in the HEP reactor and the hydrogen yield was higher than 2.66 in the tubular reactor.

In order to integrate the reforming reaction of the hydrocarbon feed gas and the combustion reaction of the stacked flue gas in the HEP reactor, a plurality of 1.1 mm thick palladium-rhodium-containing fuel reforming catalyst strips were inserted into the gas reforming section where the SMR reaction takes place, Platinum-palladium-containing fuel reforming catalysts having a predetermined thickness were inserted into the combustion zone where the combustion reaction takes place as the combustion catalyst strips.

FIG. 7A is a graph showing the methane conversion rate of the SMR reaction according to the HEP reactor temperature according to another embodiment of the present invention. The raw gas of the SMR reaction is introduced into the gas reforming unit and the nitrogen gas is introduced into the combustion unit. The activity of the reforming catalyst according to the SMR reaction temperature was very similar to the experimental data in the tubular reactor.

7B is a graph showing the combustion efficiency of the stacked flue gas of the solid oxide fuel cell according to another embodiment of the present invention as a methane oxidation rate according to the HEP reactor temperature. The stacked flue gas flows into the combustion unit, Nitrogen gas was introduced. Since the hydrogen and carbon monoxide components of the stacked flue gas were completely burned at room temperature and below 373 K, the activity of the combustion catalyst inserted into the combustion zone was represented by the conversion rate of the methane component according to the combustion temperature. As shown in FIG. 7B, the combustion reaction of the methane component started at 500 K and was completed at 850 K to 873 K.

Palladium catalysts tend to be easily fired and lose activity at temperatures above 1073 K, while palladium-rhodium-containing fuel reforming catalysts exhibit fairly good activity against SMR reactions below 1000 K, The operating temperature was set at 983 K. At this temperature, the SOFC stack flue gas was completely combusted by the platinum-palladium-containing combustion catalyst in the combustion zone, and Gas-2c was reformed in the gas reforming zone at the S / C ratio of 2.5 and GHSV 1200 / When the catalyst was reacted, the conversion rate of methane by SMR reaction was 81.5%.

The performance of the fuel reforming catalyst and the combustion catalyst did not show any tendency to decrease or decline while the SMR reaction coincided with the combustion reaction of the SOFC stack flue gas under the above reaction conditions and proceeded for 200 hours in the HEP reactor.

FIG. 8A is a graph showing a temperature profile of a gas reforming section and a combustion section in a HEP reactor according to another embodiment of the present invention, and FIG. 8B is a graph showing the temperature profile of a gas reforming section and a combustion section in a HEP reactor according to another embodiment of the present invention. 8 is a graph showing the temperature history when the GHSV is doubled as compared with the case of FIG. 8A.

Referring to FIG. 8A, the reaction heat generated by the complete combustion of Gas-3b flowing into the combustion section at GHSV 1280 / h was transferred to the SMR reaction of Gas-2b flowing into the gas reforming section at GHSV 600 / h. According to FIG. 8B, even when the GHSV in the HEP reactor was doubled to perform the reaction, the same temperature history as in FIG. 8A was obtained. Under these two test conditions, the maximum temperature of the gas reformer was 983 K in common, and the composition of the reformed gas produced was the same.

In the HEP reactor, the reforming catalyst containing palladium-rhodium and the catalyst for platinum-palladium-containing combustion were partially overlapped with each other in the lengthwise direction in which the one end thereof was inserted. The temperature of the combustion part was higher than the temperature of the gas reforming part , And the maximum temperature of the combustion zone was 1005K.

Table 6 below analyzes the energy balance including the heat of reaction in the combustion part and the gas reforming part in the HEP reactor and the heat transfer to each other.

[Table 6]

The heat generated by the complete combustion of the SOFC stack flue gas in the combustion section of the HEP reactor is transferred to the gas reforming section where the energy delivered is more than the heat required for the SMR reaction in the gas reforming section.

In the actual SOFC system, when the SMR reaction and the combustion reaction of the SOFC stack flue gas are integrated in the HEP reactor, the energy saving degree is expected to be larger than that shown in Table 6, because the stacked flue gas Is higher than that shown in Table 6 and the energy lost to the surrounding space can be minimized.

Therefore, it has been confirmed that the total amount of energy required by the endothermic SMR reaction occurring in the gas reforming section of the microchannel structure fuel reformer can be provided by heat transfer from the reaction heat of the exothermic combustion reaction occurring in the combustion section, It is proved that the thermal efficiency of the SOFC process can be improved by operating the fuel reformer.

As described above, according to the embodiment of the present invention, the palladium-rhodium-containing reforming catalyst showed excellent activity and stability in the SMR reaction as a hydrothermal reaction. Also, when the S / C ratio of the feed gas was 2.5, the methane conversion rate and hydrogen productivity were better than 983 K. The embodiment of the microchannel structure fuel reformer can be applied to the SOFC fuel reforming process owing to the excellent performance of the catalyst and the heat transfer ability inside the reactor.

While the invention has been described with reference to a limited number of embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (9)

Metal foam; And
The metal foam is formed on the palladium (Pd), rhodium (Rh) and platinum group at least one noble metal and zirconium oxide, selected from the consisting of (Pt) (ZrO _2), aluminum oxide (Al ₂ O ₃₎ and cerium oxide ( CeO2). &Lt; / _RTI &gt; The fuel reforming catalyst according to claim 1, wherein the catalyst layer contains 1.00 to 3.00 wt% of noble metal and 97 to 99 wt% of oxide. The fuel reforming catalyst according to claim 1, wherein the noble metal is mixed with palladium: rhodium at a weight ratio of 7: 1 to 3: 1. The fuel reforming catalyst according to claim 1, wherein the noble metal is mixed with platinum: palladium in a weight ratio of 2: 1 to 1: 2 and used as a combustion catalyst. The fuel reforming catalyst according to claim 1, wherein the metal foam is made of an alloy of iron (Fe), aluminum (Al), nickel (Ni) and chromium (Cr). Preparing the metal foam by pre-treating, drying and preparing the metal foam;
Coating the metal foam with a binder;
Wash coating the noble metal-oxide composite on the coated metal foam; And
And calcining the wash-coated metal foam to remove the binder. A gas reforming part formed with a raw material gas inlet through which hydrocarbon raw material gas and water vapor (H ₂ O) are introduced into one side and a reformed gas discharge port through which the reformed gas is discharged to the other side; A micro-channel structure in the form of an elongated duct including a flue gas inlet through which the stacked flue gas of the solid oxide fuel cell is formed and a flue gas outlet through which the stacked flue gas is discharged after being burned to the other side In a fuel reformer,
A gas reforming unit having a palladium-rhodium-containing reforming catalyst in the form of a thin strip and introducing the hydrocarbon feed gas and the steam to reform and discharge the hydrocarbon reforming gas using a catalyst for reforming the fuel; And
Wherein a catalyst for platinum-palladium combustion is provided in the form of a thin strip, and the stacked flue gas is introduced and combusted using a combustion catalyst, and the generated heat is transferred to the gas reforming unit, And a combustion section for exhausting gas. The gas reforming apparatus according to claim 7, wherein the gas reforming unit and the combustion unit are arranged so as to be alternately arranged so that good heat exchange occurs between the mixed flow of the raw material gas and the steam entering the gas reforming unit and the flow of the stacked flue gas flowing into the combustion unit Characterized by a microchannel structure fuel reformer. The fuel reformer according to claim 7, wherein the gas reforming section and the combustion section each have a microchannel with a narrow rectangular cross section having a gap of 1.5 mm to 2.0 mm, Wherein one end of the catalyst for the fuel reformer is disposed so as to partially overlap with the combustion catalyst in the longitudinal direction.

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