WO2007040097A1 - Steam reforming catalyst for hydrocarbon - Google Patents

Abstract

Disclosed is a steam reforming catalyst having high activity and long life, which is able to efficiently produce hydrogen by using hydrocarbon as the raw material. Specifically disclosed is a steam reforming catalyst obtained by loading an alumina carrier, which is caused to contain a rare earth metal, with at least one compound selected from ruthenium compounds and at least one compound selected from cobalt compounds. This steam reforming catalyst is characterized in that the rare earth metal is introduced into the alumina carrier by impregnation, and the amount of the rare earth metal is less than 8.5 μmol/m2 relative to the surface area of the alumina carrier. The steam reforming catalyst is further characterized in that the alumina carrier containing the rare earth metal is fired at 600-800 ˚C in the presence of oxygen before loading of the at least one compound selected from ruthenium compounds and the at least one compound selected from cobalt compounds.

Description

 Specification

 Hydrocarbon steam reforming catalyst

 Technical field

 [0001] The present invention relates to a steam reforming catalyst used for producing hydrogen from a hydrocarbon. More specifically, the present invention relates to a steam reforming catalyst that uses low-cost petroleum hydrocarbons such as LP gas, naphtha, gasoline, and kerosene that are widely distributed in the market as raw materials and steam reforms them to produce hydrogen. .

 Background art

 In recent years, with increasing environmental awareness, attention has been focused on energy using hydrogen, which has a low environmental impact. One of the energy technologies that use hydrogen is fuel cells that can extract electrical energy without the direct emission of carbon dioxide, which is said to cause ozone layer destruction and global warming, from the reaction between hydrogen and oxygen. Has been. Various raw materials such as natural gas, liquid fuel, and petroleum hydrocarbons have been studied as hydrogen sources for fuel cells. In particular, petroleum-based hydrocarbons such as LP gas, naphtha, gasoline, and kerosene are widely distributed and distributed, so they are considered promising as hydrogen sources.

[0003] As a method for producing hydrogen using petroleum hydrocarbons as a raw material, a partial oxidation method or a water vapor reforming method is known, but the latter is considered more economical to produce hydrogen. ing. A reforming catalyst is used for these hydrogen productions. As a steam reforming catalyst for hydrocarbons, Nikkenore catalysts with nickel supported on a support such as alumina are known. Power Nickel catalysts have a disadvantage that they cause a decrease in activity due to carbon deposition and have a low carbon number. When a large amount of hydrocarbon is used as a raw material, a large amount of steam is required to coexist, and the water vapor intensity increases the operating cost. Therefore, it is difficult to apply to petroleum-based hydrocarbons technically and economically. Is done. On the other hand, noble metal catalysts using noble metals such as ruthenium and rhodium have attracted attention in recent years as reforming catalysts for hydrocarbons because they have an effect of suppressing carbon deposition and reduce the amount of water vapor used. Examples include those in which ruthenium is supported on alumina (Non-patent Document 1), those in which ruthenium is supported on alumina or silica (Patent Document 1), and alumina containing alkaline earth metal aluminate and dinolecourea and ruthenium. Examples include those carrying components (Patent Document 2). However, ruthenium-based reforming catalysts are susceptible to catalyst poisoning due to sulfur contained in the raw material hydrocarbons (Non-Patent Document 2), and sulfur poisoning induces carbon deposition (Non-Patent Document 3). For this reason, it is difficult to make the carbon precipitation suppression effect function effectively. Therefore, when petroleum-based hydrocarbons are used as raw materials, the catalyst is required not only to have catalytic activity for reforming but also to suppress carbon deposition and suppress sulfur poisoning. In order to solve this problem, the conventional method has proposed the formation of a complex carrier or the addition of a third component. For example, a lanthanum oxide and cobalt supported as a cocatalyst on an alumina carrier supporting dinoleconia with zirconia sol as a precursor and containing ruthenium as an active ingredient (Patent Document 3), Ila, IIla and From the group consisting of oxides of lanthanoid metal oxides supported by a supported alumina composite containing norenium (Patent Document 4), Group 2 metals, Group 3 metals and Lanthanoid metal oxides A support obtained by calcining alumina containing 800 to 900 ° C containing 3 to 30% by weight of at least one selected catalyst based on catalyst supports 0.5 to 5% by weight of ruthenium, and 600 to 950 ° C. There have been proposed methods such as those obtained by reduction treatment (Patent Document 5) and those in which at least a ruthenium component, zirconium component and alkali metal component are supported on an alumina support (Patent Document 6). , Ru.

 However, to date, few catalysts have been designed so far that the co-catalyst and composite alumina support are designed to function in an effective form and arrangement with respect to ruthenium and have excellent thermal stability.

Patent Document 1: Japanese Patent Application Laid-Open No. 57-4232

Patent Document 2: Japanese Patent Application Laid-Open No. 5-220397

Patent Document 3: JP-A-7-88376

Patent Document 4: JP-A-8-52355

Patent Document 5: Japanese Patent Laid-Open No. 9-10586

Patent Document 6: Japanese Patent Laid-Open No. 2001-276624

Non-patent document 1: “Journal of the Fuel Society” 59 卷 25 (1980)

Non-patent document 2: “Catalyst” 35 卷 224 (1993)

Non-Patent Document 3: "Journal of Fuel Association" 68 pp. 39 (1989) Disclosure of the invention

 Problems to be solved by the invention

[0005] In the present invention, the co-catalyst introduced into the catalyst and the composite alumina support function effectively, respectively, and can suppress carbon deposition and sulfur poisoning. Therefore, it is an object of the present invention to provide a steam reforming catalyst having excellent thermal stability that can maintain its catalytic function even when exposed to long-term use conditions in which high-temperature steam coexists.

 Means for solving the problem

 [0006] In order to solve the above-mentioned problems, the present inventors have conducted intensive research. As a result, the alumina support containing a rare earth metal is selected from at least one compound selected from a ruthenium compound and a cobalt-rich compound. In the steam reforming catalyst in which at least one compound is supported, a specific amount of rare earth metal is contained in the alumina support by the impregnation method, and 600 to 600 under an oxygen atmosphere before supporting the ruthenium compound and cobalt compound. By calcining at 800 ° C, the added co-catalyst and composite carrier function synergistically with ruthenium to increase catalytic activity, and also suppress carbon deposition and suppress sulfur poisoning. The present inventors have found a highly functional steam reforming catalyst that is not available in conventional catalysts, and have completed the present invention.

 That is, the present invention is as follows.

 [1] A steam reforming catalyst comprising an alumina support containing a rare earth metal and further supporting at least one compound selected from ruthenium compounds and at least one compound selected from cobalt compounds. The rare earth metal is introduced into the alumina support by the impregnation method, and the amount of the rare earth metal is less than 8.5 a mol / m 2 with respect to the surface area of the alumina support, and at least one compound selected from the ruthenium compound and the cover. A water vapor reforming catalyst obtained by calcining an alumina support containing the rare earth metal at 600 to 800 ° C. in the presence of oxygen before supporting at least one compound selected from the above-mentioned compounds.

[2] The steam reforming catalyst according to [1], wherein the specific surface area of the alumina support is 60 m ² / g or more.

[3] The steam reforming catalyst according to [1], wherein the rare earth metal includes lanthanum or cerium. [4] Rare earth metal is introduced into the alumina support by an impregnation method so that the surface area of the alumina support is less than 8.5 zmol / m ′, and the alumina support containing the rare earth metal is added in the presence of oxygen. A method for producing a steam reforming catalyst, comprising calcining at ˜800 ° C. and then supporting at least one compound selected from ruthenium compounds and at least one compound selected from cobalt compounds.

 The invention's effect

 [0008] According to the present invention, the co-catalyst and the composite alumina support for suppressing carbon deposition and suppressing sulfur poisoning each function synergistically in an effective form and suitable arrangement with respect to ruthenium. Thus, it is possible to provide a steam reforming catalyst having excellent thermal stability that can maintain the catalytic function even when exposed to long-term use conditions in which high-temperature steam coexists.

 Brief Description of Drawings

 FIG. 1 is a graph showing the results of Experiment 1 in which steam reforming was performed using the catalysts obtained in Examples 1-2 and Comparative Examples 1-4.

 FIG. 2 is a graph showing the result of steam reforming by the method shown in Experiment 2.

 BEST MODE FOR CARRYING OUT THE INVENTION

[0010] The steam reforming catalyst of the present invention is one in which at least one compound selected from a ruthenium compound and a cobalt compound is supported on an alumina support containing a rare earth metal. The impregnation method is used to contain the metal, the amount of the rare earth metal is less than 8.5 z mol / m ^{2 with} respect to the surface area of the alumina support, and the oxygen atmosphere is supported before loading the ruthenium compound and the cobalt compound. It is important to fire at 600-800 ° C.

[0011] In the steam reforming catalyst of the present invention, the alumina support is not particularly limited by the composition and structure, but the specific surface area is 60 m ² / g so that the supported ruthenium and cobalt can be sufficiently dispersed. As described above, preferably, it is 80 to 120 m ² / g, and the pore volume is 0.1 to 0.5 ml / g, preferably 0.2 to 0.5 ml / g. As an example, it is possible to use a material obtained by baking aluminum isopropoxide as a precursor and adding a pore-controlling organic material at 700 ° C or higher. Specific surface area and pore volume If it is smaller, the dispersibility of the supported ruthenium is deteriorated and the predetermined activity and catalyst life cannot be obtained. On the other hand, if it is larger than this, sufficient carrier strength cannot be obtained.

 [0012] Examples of the shape of the alumina carrier include a spherical shape, a cylindrical shape, a prismatic shape, a tableting shape, a needle shape, a membrane shape, and a honeycomb structure. For molding the carrier, for example, molding methods such as pressure molding, extrusion molding, rolling granulation molding, and press molding can be used. Any known method can be used without any particular limitation to limit the present invention.

 [0013] By using the rare earth metal, the catalytic activity is increased and the catalyst life is improved. For rare earth metals, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, ytterbium, etc. can be used. In particular, lanthanum and cerium should be used. Any of these rare earth metals may be used alone or in combination of two or more. These rare earth metals can be used as precursors of rare earth metal compounds such as chlorides, nitrates and acetates in addition to oxides.

 [0014] The alumina support containing the rare earth metal can be selectively distributed on the surface of the support by introducing the rare earth metal into the alumina support by an impregnation method. By selectively distributing the rare earth metal on the alumina surface, a large effect can be obtained with a small amount of additive, and the mechanical strength and heat resistance of the carrier are improved by coating the alumina surface with the rare earth metal. . In the physical mixing method and the kneading method, rare earth metal is distributed inside the alumina support, and the rare earth metal distributed inside the alumina carrier is wasted, so that an effective addition effect (hereinafter referred to as an effect of addition amount) cannot be obtained. Negative effects such as increase in raw material cost due to a large relative decrease in the amount of alumina, lowering the mechanical strength of the support, and the rare earth metal forming a complex oxide with alumina, which significantly impairs the specific surface area of the support Is not preferred because it tends to appear. In order to introduce the rare earth metal into the alumina support by the impregnation method, the alumina support may be immersed in a solution containing the rare earth metal compound. At this time, the solvent is preferably water. Moreover, when impregnating, the pore filling method is preferable.

[0015] In addition, when the rare earth metal is introduced into the alumina support by the impregnation method and distributed on the surface of the support, it is important to coat the surface of the alumina with the rare earth metal so that the active metal can be in direct contact with the alumina. . Rare earth metal covered the entire surface area of alumina support with a single layer In this state, the amount of the rare earth metal contained in the alumina support is 8.5 x molZm ² with respect to the surface area of the alumina support as its oxide. If the amount of rare earth metal exceeds 8.5 μmolZm ² , it cannot be distributed as a single layer on the surface of the alumina support, and the excess forms a multimolecular layer. When the rare earth metal covers the entire surface area of the alumina support with a single layer, or forms a multi-layer, the alumina support and the active metal cannot be in direct contact with each other. The weakening of the action is not preferable because the stability of the active metal on the catalyst surface and the activity are easily lowered. Therefore, the amount of rare earth metal should be less than 8.5 μmol / m ² with respect to the surface area of the alumina support so that the active metal can be in direct contact with the alumina. In addition, if the amount of rare earth metal is small, the effect of addition becomes low, which is not preferable. More preferably, it is 0 · 8 i mol / m ² or more and less than 8.5 · mol / m ² .

 The amount of the rare earth metal contained in the alumina support can be adjusted to the above range by adjusting the concentration of the rare earth metal compound in the solution impregnated in the alumina support.

 [0016] After the rare earth metal is incorporated into the alumina support by the impregnation method, it is 600 to 800 ° C, preferably 650 to 750 ° C, more preferably 700 in the presence of oxygen before the ruthenium compound and the cobalt compound are incorporated. Calcination at ~ 750 ° C to fix rare earth metal as oxide to alumina support. Firing in the presence of oxygen may be performed in the air. At this time, if the firing temperature is lower than 600 ° C, the introduced rare earth metal is not stabilized on the support surface, and the alumina support becomes susceptible to deterioration due to the thermal history under the conditions of the steam reaction, and the temperature exceeds 800 ° C. In other words, the introduced rare earth metal reacts with the alumina support to form a composite oxide (aluminate), and the specific surface area of the support is not only greatly impaired. The distributed active metal ruthenium is not preferable because it does not function effectively.

[0017] A known impregnation method can be used as a method for supporting a ruthenium compound and a cobalt compound on the above-mentioned alumina support containing a rare earth metal. As the ruthenium compound, a compound such as trisalt ruthenium or ruthenium nitrate can be used as a precursor of the ruthenium active ingredient. Particularly preferred is trisalt ruthenium (anhydride or hydrate). The amount of ruthenium compound supported depends on the surface area of the support, but is generally a catalyst. The metal content is 0.3 to 5.0% by weight, preferably 0.5 to 3.0% by weight based on the weight. If the supported amount of ruthenium is less than this, the amount of ruthenium that functions as an active site decreases and sufficient catalytic activity cannot be obtained, and if the supported amount is too large, the dispersibility of ruthenium decreases and the ruthenium does not function effectively. Preferred les. The cobalt compound serving as a cocatalyst can be supported on the support after the rare-earth metal is fixed as an oxide on the alumina support before or after the ruthenium compound is supported, or simultaneously with the ruthenium compound. In particular, the cobalt compound is supported simultaneously with the noretenium compound, thereby enhancing the dispersibility of ruthenium and significantly improving the catalytic activity. Also, it acts as a wedge against ruthenium, which suppresses ruthenium crystallization, and suppresses agglomeration of ruthenium that progresses during the reforming reaction, thereby suppressing catalyst degradation. Therefore, it is preferable to simultaneously carry a cobalt compound and a ruthenium compound since these effects are more emphasized. As the cobalt compound, a compound such as cobalt nitrate, cobalt carbonate, cobalt acetate, cobalt hydroxide, cobalt chloride and the like can be used as a precursor of the cobalt promoter component. Particularly preferably, cobalt nitrate is used.

 [0018] The amount of cobalt in terms of an atomic molar ratio to ruthenium (hereinafter referred to as Co / Ru ratio) is 0 :! to 3, preferably ί or 0.1 to 1.0, and more preferably 0.25 to 0.2. 5. If the Co / Rui force is less than SO.1, the cocatalyst effect does not sufficiently appear, and if it is 3 or more, excess cobalt adversely affects the catalytic function of ruthenium, which is not preferable.

 [0019] The drying process and the baking process after supporting the ruthenium compound and the cobalt compound are not particularly defined for the conditions, but are performed, for example, in air at 100 ° C or higher. In addition, the obtained catalyst may be subjected to reduction treatment in a liquid phase for the purpose of reducing the load such as pretreatment reduction when using the reforming reaction or heat generation at the initial stage of the reaction. For the reduction treatment, for example, a 1-20% aqueous solution is prepared using a reducing agent such as formic acid, alkali metal salt of formic acid, honoremarin, hydrazine, sodium borohydride, etc., and the temperature is adjusted to room temperature to 60 ° C. After heating, add the catalyst.

[0020] The steam reforming catalyst obtained by the above method is preferably subjected to reduction treatment before the reforming reaction, but the reduction is performed as a result of contact with hydrogen in the reaction gas generated in the reforming reaction. Therefore, it is not always necessary. By controlling the reduction temperature, the catalyst performance is improved. When the reduction treatment is carried out, it is carried out at 700 ° C or lower, preferably 600 to 700 ° C under hydrogen gas flow. If it exceeds 700 ° C, the dispersibility of ruthenium is lowered before the steam reforming reaction, and as a result, the catalyst performance is impaired.

 The steam reforming catalyst of the present invention can be used in a process for producing hydrogen from hydrocarbons in the presence of steam. It can be applied to the production of hydrogen for hydrorefining at refineries, etc. where there are no particular restrictions on the application to the hydrogen production process, and the production of hydrogen for fuel cells in stationary distributed power sources. The hydrocarbon is not particularly limited, for example, saturated aliphatic hydrocarbon compounds having 1 or more carbon atoms, such as methane, ethane, propane, butane, pentane, hexane, heptane, and octane, cyclopropane, cyclobutane, cyclopentane, Examples thereof include saturated alicyclic hydrocarbon compounds having 3 or more carbon atoms typified by cyclohexane and the like, and aromatic hydrocarbon compounds typified by benzene, toluene, xylene and the like. Petroleum fractions represented by LP gas, naphtha, gasoline, kerosene, light oil, etc. obtained by petroleum refining, which may be a mixture containing one or more of these, are some of those fractions. There may be. The sulfur content in hydrocarbons is 0.2 ppm by weight or less, preferably 0.05 ppm by weight or less. If the sulfur content exceeds 0.2 ppm by weight, catalyst poisoning due to sulfur compounds becomes significant, and the catalyst activity decreases and the life of the catalyst tends to advance. Even for hydrocarbons with a sulfur content of more than 0.2 ppm by weight, pretreatment such as hydrodesulfurization or adsorptive desulfurization is performed before the reforming reaction, so that the sulfur content is less than 0.2 ppm by weight. The steam reforming catalyst of the present invention can be used by reducing it to a low level. The lower the sulfur content of hydrocarbons in this pretreatment, the more preferable it is because catalyst poisoning by sulfur can be reduced.

[0022] The hydrocarbon reforming reaction performed using the steam reforming catalyst of the present invention has a steam / carbon ratio (hereinafter referred to as S / C ratio) of:! To 10, preferably 2 to 5. If the S / C ratio is less than 1, the decrease in the catalyst activity is remarkably accelerated, and if it is 10 or more, the steam unit supplied is excessive, resulting in an increase in cost. The reaction temperature depends on the type of hydrocarbon, but is usually 400 to 800 ° C, preferably 500 to 750 ° C. Even if the reaction temperature is less than 400 ° C, the steam reforming reaction proceeds, but the ratio of hydrogen generated thermodynamically decreases and the hydrogen yield decreases, which is preferable. If the temperature exceeds 800 ° C, the thermal degradation will accelerate and the catalyst life will be significant. It is not preferable because it decreases.

[0023] The reaction system using the steam reforming catalyst of the present invention is not particularly limited, such as a continuous flow system or a batch system, but is preferable because the former can efficiently perform the reforming reaction. Liquid hourly space velocity of hydrocarbons in this case (hereinafter, LHSV) is the force usually 10 hr ^{_ 1} below also depend on the type of hydrocarbon, preferably 5 hr ^_1 below. Possible reforming reaction even L HSV exceeds the 10 hr ^{_ 1} depending on the type of hydrocarbons, but economically preferable because it is necessary to plant capacity to supply a large amount of hydrocarbon and steam. The reaction pressure depends on the type of hydrocarbon and is usually 0 to 5 MPa, preferably 0 to 2 MPa. If the reaction pressure exceeds 5 MPa, equipment using expensive pressure-resistant materials is required, which is not economically preferable.

 [0024] The reaction mode using the steam reforming catalyst of the present invention is not particularly limited, such as a fixed bed type, a moving bed type, and a fluidized bed type. The reactor using the steam reforming catalyst of the present invention is not particularly limited. The steam reforming catalyst of the present invention can be used alone or in combination with other catalysts.

 Example

 [0025] Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

[0026] [Preparation of catalyst]

 Example 1 (Catalyst A)

After impregnating 150 ml of an aqueous solution in which 87.7 g of lanthanum nitrate hexahydrate is dissolved in 415 g of a ² mm diameter alumina support (specific surface area 120 m ² / g, pore volume 0.36 ml / g) by 110 ° Drying was performed at C for 16 hours, followed by baking at 650 ° C for 3 hours in the presence of oxygen. The obtained lanthanum-containing support was impregnated with 150 ml of an aqueous solution in which 23.3 g of ruthenium trichloride and 10.2 g of cobalt nitrate (II) hexahydrate were dissolved, and then dried at 150 ° C. for 16 hours. . The obtained catalyst was subjected to liquid phase reduction treatment at 40 ° C. using an aqueous hydrazine carbonate solution and dried at 150 ° C. for 10 hours to obtain Catalyst A.

[0027] Comparative Example 1 (Catalyst B)

A catalyst B was obtained in the same manner as in Example 1 except that cobalt nitrate was not used in the method of Example 1. [0028] Comparative Example 2 (Catalyst C)

 A catalyst C was obtained in the same manner as in Example 1 except that lanthanum nitrate was not used in the method of Example 1.

[0029] Comparative Example 3 (Catalyst D)

 In the method of Example 1, catalyst D was prepared by the same preparation method as in Example 1 except that the calcination treatment after supporting lanthanum nitrate was performed at 850 ° C. for 3 hours in the presence of oxygen. .

[0030] Example 2 (Catalyst E)

 A catalyst E was obtained in the same manner as in Example 1 except that 35.3 g of lanthanum nitrate hexahydrate was used in the method of Example 1.

[0031] Comparative Example 4 (Catalyst F)

 A catalyst F was obtained in the same manner as in Example 1, except that 147 g of lanthanum nitrate hexahydrate was used in the method of Example 1.

[0032] Table 1 shows the compositions measured by IPC mass spectrometry and the specific surface areas obtained by the nitrogen adsorption method for the catalysts A to F obtained by the above preparation.

[0033] [Table 1]

[Experiment 1]

1 Each catalyst 15cc sized to 3mmφ is uniformly diluted with 2mmφ inert alumina 35cc into a SUS cylindrical reaction tube with an inner diameter of 30mmφ, and the gas space velocity (GH SV) = 2000hr— ^After heating up at a rate of 10 ° C / min. Under a hydrogen flow of ¹ and performing reduction treatment at 600 ° C for 90 minutes, kerosene obtained by desulfurizing commercially available JIS1 kerosene to a sulfur concentration of 50ppb ( In the following, steam reforming reaction was performed using LHSV = 5. Ohr- ¹ , steam Z carbon ratio = 3.0, reaction pressure 0.10 MPa_G, 600 ° C using desulfurized kerosene) as the feedstock. Table 2 shows the properties of the desulfurized kerosene used as the feedstock.

 [Table 2]

[0036] The product obtained by the above steam reforming reaction was sampled in a gas state, and the product composition was analyzed by gas chromatography. The catalytic activity of the reforming catalyst obtained in each of the above examples was evaluated using the C1 conversion rate obtained by the following formula as an index.

 C1 conversion (%) = & ÷ 1) 100

 a: Mono number of C1 compounds (methane, carbon monoxide, carbon dioxide) contained in the product at the outlet of the reactor

 b: Total number of moles of carbon contained in the raw material hydrocarbon (desulfurized kerosene)

 Examples: FIG. 1 shows the results of the steam reforming reaction carried out under the above-mentioned conditions using the catalysts obtained in! -2 and Comparative Examples 1-4. Catalyst A and Catalyst E obtained according to the present invention have a higher C1 conversion rate and higher activity than when the catalysts of Comparative Examples 1 to 4 are used, and maintain a high conversion rate even after a lapse of time. It can be seen that the catalyst is less deteriorated.

[0037] [Experiment 2]

スチーム/カーボ ン比 = 3. 0、反応圧力 0. OOMPa— G (大気圧）、 600°Cで水蒸気改質反応を行つ た結果を図 2に示す。図 2から本発明の触媒は灯油の水蒸気改質反応において 400 0時間以上経過した後も CI転化率は 100%を維持しており、実用に応えうる高活性 かつ長寿命な触媒性能を有することを示す。 Using the catalyst A obtained in Example 1, Experiment 1 Similarly GHSV = 2000 hr ^{_ 1} under hydrogen stream 10 ° C / min. For 90 minutes at 600 ° C carried out heating at a rate reduction After the treatment, LHSV = 0.

Figure 2 shows the results of a steam reforming reaction at a steam / carbon ratio of 3.0, a reaction pressure of 0. OOMPa-G (atmospheric pressure), and 600 ° C. From FIG. 2, the catalyst of the present invention is used in the steam reforming reaction of kerosene. Even after 0 hours or more have passed, the CI conversion rate is maintained at 100%, which indicates that the catalyst performance has high activity and long life that can meet practical use.

Claims

The scope of the claims  [1] A steam reforming catalyst in which a rare earth metal is contained in an alumina support and at least one compound selected from ruthenium compounds and at least one compound selected from cobalt compounds are supported. The rare earth metal is introduced into the alumina support by an impregnation method, and the amount of the rare earth metal is less than 8.5 μmol / m3 with respect to the surface area of the alumina support, and is at least one compound selected from the ruthenium compounds. And a steam reforming catalyst characterized by calcining the alumina support containing the rare earth metal at 600 to 800 ° C. in the presence of oxygen before supporting at least one compound selected from the group consisting of cobalt compounds. [2] The steam reforming catalyst according to claim 1, wherein the specific surface area of the alumina support is 60 m ² / g or more.  [3] The steam reforming catalyst according to claim 1, wherein the rare earth metal contains lanthanum or cerium. [4] Rare earth metal is introduced into the alumina support by an impregnation method so that the surface area of the alumina support is less than 8.5 μmol / m ² , and the alumina support containing the rare earth metal is present in the presence of oxygen. A method for producing a steam reforming catalyst, comprising calcining at 600 to 800 ° C and then supporting at least one compound selected from ruthenium compounds and at least one compound selected from cobalt compounds.