Substrate monolith comprising reforming catalyst

Abstract

The invention relates to a catalyst body in the form of a substrate monolith, and to a device for reforming, in particular adiabatic reforming, hydrocarbons, in particular methane from natural gas. The catalyst body contains a noble metal and a support oxide for the noble metal. A method for producing the catalyst and the use of the catalyst for producing hydrogen are also claimed. The noble metal is selected from platinum, palladium and rhodium, and the molar ratio M1 / M2 at the inlet region of the substrate monolith is higher than the molar ratio M1 / M2 at the other end, where M1 is Pt and / or Pd, and M2 is Rh.

Description

[0001] Specification

[0002] The present invention relates to a catalyst body in the form of a substrate blank, and to a device for the reforming, in particular the adiabatic reforming, of hydrocarbons, in particular methane from natural gas. The reforming catalyst contains a noble metal and a support oxide for the noble metal. Also claimed are a method for producing the catalyst and the use of the catalyst for producing hydrogen.

[0003] Low-emission transport and low-emission power generation will play an increasingly important role in the future. One way to achieve low-emission transport and low-emission power generation is to use hydrogen as an energy carrier. There are many ways to do this. A problem in this context is the production and storage of hydrogen. Hydrogen is very volatile and, as the lightest chemical element, can only be liquefied or stored under extreme conditions.

[0004] Accordingly, there is an increasing search for solutions for generating hydrogen where it is needed. One way to generate hydrogen in situ is to convert hydrocarbons, such as natural gas, via a reforming catalyst at elevated temperatures. Hydrocarbons and natural gas are relatively easy to store and are available almost anywhere due to the existing infrastructure. The hydrogen can then be converted, for example, into an electric current in a fuel cell, which can be used for mobile or stationary applications.

[0005] The corresponding methods and catalysts for reforming are known to those skilled in the art (e.g. WO201103338A2, WO2003104143A1, US2013079217AA, US2009283419AA, US2008219918AA, EP2251080A1). WO2005056179A1 describes a catalyst for reforming hydrocarbons to produce hydrogen, which catalyst contains a noble metal and a support oxide. In particular, support oxides based on alumina, magnesia and ceria are proposed herein. The alumina is mixed into the support oxide in the form of a spinel containing magnesium. The composition of the support oxide is completed by further addition of alumina and addition of ceria.

[0006] Despite many proposals for the corresponding catalysts, the problem of providing further improved catalysts for reforming hydrocarbons remains. These reforming catalysts should have sufficient stability and activity so as to be able to produce hydrogen under the most efficient conditions possible. In addition, the corresponding catalysts should be highly robust and durable and as cost-effective as possible. In particular, the significant increase in the price of rhodium requires further optimization of such catalysts, especially in terms of their activity. Against this background, replacing rhodium with platinum may help, platinum being less active in, for example, the steam reforming of methane but having the advantage of being significantly lower in price and thus more advantageous to use.

[0007] These and other problems that are clearly present in the prior art are solved by a substrate blank comprising the features of claim 1 of the present invention. Claims 2 to 6 relate to preferred embodiments of the catalyst according to the present invention. Claim 7 relates to a device for power generation, and claim 8 relates to a method for producing the corresponding catalyst. Claims 9 to 12 relate to its suitable uses.

[0008] By specifying a substrate blank comprising a reforming catalyst for producing hydrogen from hydrocarbons, in particular methane, a very simple but equally surprising solution to the said problems can be found. The reforming catalyst comprises a noble metal and at least one support oxide on which the noble metal is deposited, wherein the noble metal is selected from the group consisting of Pt, Pd and Rh, and M1 / M2 at the inlet region of the substrate blank is greater than M1 / M2 at the other end, where M1 = Pt and / or Pd and M2 = Rh. Thus, M1 and M2 describe the molar amounts of Pt and / or Pd and Rh in the substrate blank. For example, they are measured as follows: once at the front of the inlet region (5 mm from the starting point of the substrate blank in the flow direction) and once at the outlet region (5 mm from the end of the substrate blank in the direction opposite to the flow direction). The inlet region of the substrate blank is the region that first comes into contact with the inflowing gas.

[0009] Compared with examples of the prior art, the substrate blank according to the present invention comprising the reforming catalyst proposed herein shows extremely advantageous activity. The asymmetric distribution of the noble metals according to the present invention results in a catalyst that on the one hand shows good activity and on the other hand is optimized with respect to the use of expensive noble metals. In particular, the zoned construction allows for a simple design of the present invention in terms of the production technology regarding the noble metal distribution. Furthermore, the catalyst is very robust under changing environmental conditions and shows extraordinary long-term stability (see Table 2). This was unexpected as of the priority date.

[0010] The reforming catalyst according to the present invention is surprisingly simple in structure. The reforming catalyst advantageously consists of a noble metal deposited on a support oxide, in particular Pt and Rh or only Pt or Rh, optionally in corresponding zones or with a corresponding concentration gradient. It has been shown that it is advantageous for the noble metals, in particular Pt and Rh, to be deposited on the oxide together. In this case, co-deposition means that there is no differentiation with respect to the oxide to the extent that, for example, Rh is only deposited on cerium oxide and Pt is only deposited on alumina. During co-deposition, alloying of the noble metals, in particular by alloying Pt and Rh, can have a beneficial effect on the substantial production of hydrogen (CH4 + 2H2O -> 4H2 + CO2).

[0011] All materials familiar to those skilled in the art for this purpose, such as Al2O3, CeO2, ZrO2, TiO2, La2O3, BaO, SnO2, ZnO, MgO, HfO2 and MnO2, and their mixtures or mixed oxides, among others, can be considered as components of the support oxide in the context of the present invention. In this case, optionally doped mixed oxides (such as cerium-zirconium mixed oxides) can also be used. In this case, a physical mixture containing alumina, cerium dioxide and / or spinel (MgAl2O4; https: / / de.wikipedia.org / w / index.php?title=Spinell&oldid=224329096) is advantageously used. The composition of the support oxide can be variable. Alumina, cerium oxide and spinel preferably exist separately as the support oxide. Possible compositions can be obtained by physical mixtures as required, but preferably may include at least all three components. Further preferred mixtures are between 5MgAl2O4 + CeO2 + 1.7Al2O3 and 20MgAl2O4 + CeO2 + 6.9Al2O3. A particularly preferred composition is 8 to 9MgAl2O4 + CeO2 + 2 to 4Al2O3. Suitable support oxides can also be taken from the prior art mentioned at the beginning.

[0012] In the present context, particularly suitable aluminas are selected from the series consisting of alumina and doped aluminas. Doped aluminas are, for example, aluminas doped with lanthanum oxide, zirconium oxide, silicon oxide, cerium oxide, barium oxide and / or titanium oxide. Advantageously, alumina, La-doped alumina or Cer-doped alumina is used, in each case calculated as La2O3 and based on the weight of the stabilized alumina, the amount of lanthanum being specifically 1 wt% to 10 wt%, preferably 3 wt% to 6 wt%. Additionally, in the case of doping alumina with barium oxide, in each case calculated as BaO and based on the weight of the stabilized alumina, the proportion of barium oxide is specifically 1 wt% to 10 wt%, preferably 3 wt% to 6 wt%. Particularly suitable alumina is lanthanum-stabilized alumina, which is optionally additionally doped with cerium oxide, barium oxide and / or strontium oxide. The support oxide preferably contains at least one alumina or doped alumina. Particularly preferred herein is specifically γ-alumina or La-stabilized γ-alumina, which has a BET surface area of 30 m 2 / g to 250 m 2 / g, preferably 100 m 2 / g to 200 m 2 / g (determined according to the latest version of DIN 66132 as of the filing date). Such activated aluminas are widely described in the literature and, as mentioned above, are commercially available (for example from The company obtained). Most preferably, it is alumina or doped alumina with a particle size distribution d50 value < 100 μm, preferably < 70 μm, and most preferably < 50 μm (Q3 distribution, the latest version of ISO 13320-1 as of the filing date).

[0013] The support oxide preferably contains at least one high-surface-area and temperature-stable cerium oxide (such as EP1435338A1), which is also commercially available (such as from the company obtained). The amount of cerium oxide in the support oxide is from 1 wt% to 20 wt%, preferably from 8 wt% to 12 wt%.

[0014] The support oxide preferably has at least one MgAl2O4-type spinel as a third component. The spinel is particularly preferably used as the main component in the support oxide, and its amount is from 50 wt% to 90 wt%, preferably from 60 wt% to 80 wt%. This can be produced by oneself (such as DE1571299B2; https: / / de.wikipedia.org / w / index.php?title=Spinelle&oldid=225306698), and can also be commercially available. The remainder of the support oxide is preferably only the above-mentioned alumina.

[0015] Particularly advantageously, the reforming catalyst of the present invention contains only the components just mentioned. In particular, it does not require any additional transition metals or transition metal oxides. The catalyst of the present invention advantageously does not contain elements selected from the group consisting of zirconium, chromium, and nickel.

[0016] The reforming catalyst is generally present as a conventional coating on a substrate monolith. In this regard, embodiments in which the reforming catalyst according to the present invention contains an additional binder are therefore advantageous. For example, active temperature-stable metal oxides with little or no catalytic activity such as SiO2, Al2O3, and ZrO2 are suitable as binders. Those skilled in the art know the materials that can be used here. The proportion of such a binder in the reforming catalyst can reach, for example, at most 10 wt%, preferably at most 5 wt% of the total mass of the reforming catalyst. The binder is suitable for ensuring stronger adhesion of the coating to the support. For this purpose, a specific particle size of the metal oxide in the binder is advantageous. This can be adjusted accordingly by those skilled in the art according to individual requirements. For example, adding a sol of the above elements to the coating suspension has proven to be advantageous. In this context, aluminum sols such as or boehmite (https: / / de.wikipedia.org / w / index.php?title=B%C3%B6hmit&oldid=226104395).

[0017] The reforming catalyst comprises noble metals deposited on a support oxide, in particular Pt and Rh. Preferably only Pt and Rh are used. Thus, the molar ratio of Pt to Rh in the substrate monolith is preferably from 1:2 to 8:1, more preferably from 1:1 to 5:1, and most preferably from 2:1 to 3:1. In the corresponding zones, Pt may also be absent and only Rh present, or Pt present and Rh absent (e.g. Figure 1 c).

[0018] In this case, according to the invention, the ratio M1 / M2 varies along the length of the substrate monolith. Pt and / or Pd are present in any case at the front (5 mm from the inlet of the substrate monolith). The zone is particularly preferably located in the inlet region of the substrate monolith, which particularly contains Pt and has a higher M1 / M2 ratio than the zone located in the outlet region of the substrate monolith. Thus, the inlet region of the substrate monolith is the first to come into contact with the inflowing gas. The reforming reaction occurring throughout the substrate monolith is significantly endothermic. This results in a significantly lower temperature in the outlet region than in the inlet region. Thus, the substrate monolith must be able to withstand its typical large temperature gradient.

[0019] For this purpose, the following Table 1 gives the advantageous values of M1 / M2 for the front (5 mm from the inlet of the substrate monolith) and the rear (5 mm from the end of the substrate monolith):

[0020] Table 1 :

[0021] Value M1 / M2 Front part Rear part Preferably 1-∞ 1-0.01 More preferably 100-∞ 1-0.1 Most preferably ∞ 1-0.5

[0022] The present invention relates to a substrate monolith comprising a reforming catalyst. The reforming catalyst can be applied to the substrate monolith by coating steps familiar to those skilled in the art, preferably to a flow-through substrate (DE102019100099A1 and the documents cited therein). In this context, filter substrates such as wall-flow filters are also possible. Flow-through substrates are substrate monoliths commonly used in the prior art, which can be composed of metals (such as WO17153239A1, WO16057285A1, WO15121910A1 and the documents cited therein) or ceramic materials. "Corrugated substrates" can also be considered as flow-through substrates. These are known to those skilled in the art as carriers, which are made of corrugated sheets composed of inert materials. Suitable inert materials are, for example, fibrous materials having an average fiber diameter of 50 μm to 250 μm and an average fiber length of 2 mm to 30 mm. Fiber heat-resistant materials made of silica, especially glass fibers, are preferred. However, refractory ceramics such as cordierite, silicon carbide or aluminum titanate are preferably used as honeycomb carriers. The number of channels per surface area of these carriers is characterized by the pore density, and the pore density generally ranges between 300 cells per square inch (cpsi) and 900 cpsi. The wall thickness of the channel walls in the ceramic is between 0.5 mm and 0.05 mm.

[0023] The absolute length of the substrate monolith comprising the reforming catalyst according to the present invention can also be adjusted by those skilled in the art and adapted to individual needs. It has been proven that lengths of 5.0 cm to 16.0 cm, preferably 6.0 cm to 14.0 cm and most preferably 7.0 cm to 13.0 cm are advantageous for the intended use of the present invention.

[0024] The total amount of the coating in the substrate monolith is selected such that the catalyst according to the present invention is utilized as effectively as possible overall. In the case of a flow-through substrate, the total amount of the reforming catalyst in the coating (solid proportion) / carrier volume (total volume of the carrier) can be, for example, between 100 g / L and 300 g / L, especially between 120 g / L and 250 g / L. The total noble metal content of the substrate monolith is preferably 0.015 g / L to 5 g / L of the carrier volume, more preferably 1.0 g / L to 3.0 g / L of the carrier volume, and particularly preferably 1.6 g / L to 2.2 g / L of the carrier volume. If platinum or palladium is used, it should be in the range of 0.5 g / L to 2.5 g / L of the carrier volume in the coating, more preferably 1.3 g / L to 1.9 g / L of the carrier volume. Rhodium is present in the reforming catalyst in an amount of 0.1 g / L to 1.0 g / L, more preferably 0.3 g / L to 0.4 g / L of the carrier volume in the relevant components.

[0025] In another preferred embodiment, the substrate monolith discussed herein has a design that is particularly advantageous for the intended use of the present invention. In this case, a zoned design is particularly suitable. The zoned design is preferred, as shown by the examples in Figure 1 . It is particularly preferred to construct the substrate monolith in such a way that it has a coated zone containing Pt on a support oxide on the upstream side and a coated zone containing a metal mixture of Pt and Rh on a support oxide on the downstream side. It may also be advantageous if both zones contain Pt and Rh, with the former zone containing a higher concentration of Pt and the latter zone containing a higher concentration of Rh. In the context of the present invention, if Pt and Rh occur together in a zone or together in the entire substrate monolith (e.g., Figure 2 ), it is surprisingly advantageous to mix them before introducing them into the washcoat so that methane reforming can be carried out as effectively as possible. Those skilled in the art know how to do this in this regard. The zones can also be located on different flow-through substrates that are directly connected one after another. Upstream means that this zone first comes into contact with the medium to be converted, and then the other zone comes into contact with the medium. Downstream should be understood accordingly.

[0026] The corresponding coatings on the substrate monolith are used in an amount of 15 g / L to 200 g / L of the total support volume, particularly between 100 g / L and 200 g / L of the total support volume, and particularly preferably in the range of approximately 120 g / L to 180 g / L of the total support volume. In this case, the total noble metal content in the coating can be in the range of 0.01 g / L to 3.0 g / L of the total support volume, more preferably 1.65 g / L to 2.15 g / L of the total support volume. Rh is advantageously contained in the corresponding zone in an amount preferably of 0.07 g / L to 0.5 g / L, particularly 0.1 g / L to 0.35 g / L. The platinum content in the corresponding zone is also preferably 0.07 g / L to 2.0 g / L of the total support volume, more preferably 0.5 g / L to 1.3 g / L of the total support volume.

[0027] Depending on the gas composition and the temperature profile of the catalyst, in addition to Rh, Pt can be present in the downstream zone. The Pt / Rh zone preferably contains a Pt:Rh molar ratio of 1:1, but can also have other ratios from 3:1 to 1:2, depending on the gas composition and the temperature profile of the catalyst. It is also advantageous to use only rhodium as the noble metal in this zone.

[0028] As already pointed out, the preferred zones are located on the substrate blank. The preferred zones can also be located on two substrate blanks, which are then arranged directly one after the other. The zone length can be selected by a person skilled in the art. It has been shown to be advantageous that the upstream zone in the reforming catalyst according to the invention is shorter than the downstream zone due to a significant temperature drop in the catalyst. The ratio of the zone lengths is preferably between 50 / 50 and 30 / 70, and more preferably about 40 / 60 to 30 / 70.

[0029] The invention also relates to a device for power generation, which comprises the substrate blank just outlined and a fuel cell in fluid contact therewith. Such devices and their design principles are known to a person skilled in the art in principle (e.g., JP2008007359(A), CN111029628). Via a fluid connection, the hydrogen produced on the substrate blank by the reforming catalyst according to the invention is brought into contact with the anode of the fuel cell. The hydrogen is then converted into hydrogen ions, which oxidize with oxygen in the atmosphere at the cathode to form H2O, which can be released into the ambient air.

[0030] The invention also relates to a method for producing the corresponding reforming catalyst substrate, in which the substrate blank is coated with a coating suspension containing the reforming catalyst components according to the invention in water, subsequently dried and calcined, and finally tempered at a temperature of 500 °C to 600 °C for at most 2 hours.

[0031] In the first step, a coating suspension is preferably produced from a support oxide component and an optional binder in water. The suspension is then mixed with a solution of a water-soluble noble metal compound, in particular an Rh compound and an optional Pt compound. Thus, the noble metals are preferably deposited together on the entire support oxide by mixing and subsequent injection. It is also possible to produce the oxides provided with noble metals separately and then mix them. Producing the corresponding suspension for coating the substrate is known to a person skilled in the art in the field of automotive exhaust catalysts (e.g., DE202016008848A1).

[0032] Subsequently, the suspension is applied to the substrate blank, in particular a flow-through substrate. These procedures are also familiar to a person skilled in the art, for example, a person skilled in the art from the field of automotive exhaust catalysts (e.g., WO2020141188A1 and the documents cited therein). These zones can be coated using methods familiar to a person skilled in the art (e.g., EP1273344A1, EP2533901A1). The coated substrate blank is then optionally dried and calcined. It has been shown to be advantageous that the coated substrate blank is finally tempered at a slightly higher temperature to completely remove the organic components of the coating, such as CO2 or NO x . This also makes it possible to establish an oxide-based mass balance.

[0033] Particularly advantageously, the coated substrate blank is dried at from 100°C to 150°C, preferably from 110°C to 130°C. The calcination temperature should not be too high. It is preferably between 300°C and a maximum of 500°C, preferably between 320°C and 400°C. Subsequently, the catalyst is tempered at a temperature of from 400°C to 600°C, preferably from 520°C to 580°C, for preferably at most 6 hours, more preferably at most 4 hours, particularly preferably at most 3 hours or 2 hours. Subsequently, the reforming catalyst on the substrate blank is ready to be inserted into the device according to the invention.

[0034] The invention also relates to the use of a substrate blank according to the invention comprising a reforming catalyst for producing hydrogen from hydrocarbons, in particular methane. Methane is the most stable hydrocarbon. It is relatively difficult to carry out the conversion using a catalyst. However, it is the main component of natural gas. The reforming catalyst according to the invention is capable of converting methane in a satisfactory manner. Therefore, the conversion is preferably carried out adiabatically at a temperature of from 300°C to 900°C, preferably from 650°C to 800°C, in an atmosphere preferably consisting of methane, steam and additionally CO, CO2 and H2 (by possible exhaust gas recirculation). A preferred use is the production of hydrogen from natural gas (CNG, LNG).

[0035] The substrate blank according to the invention is used for reforming hydrocarbons. When hydrocarbons, in particular methane, are converted at elevated temperatures, a surprisingly large amount of hydrogen is produced. Since the reactions taking place are endothermic in nature, it is advantageous to minimize the heat loss to the environment by means of as much thermal insulation as possible in order to maintain as low a heat dissipation as possible. Therefore, during use according to the invention, it is advantageous if this use is carried out under adiabatic conditions, i.e. with little or no heat exchange with the environment in both directions. The use should preferably be designed such that, based on the heat supplied in the form of heated reaction gas via the substrate blank, the heat exchange with the environment is between 0% and 15%, preferably less than 10%, most preferably less than 5%. A person skilled in the art knows how to isolate the substrate blank from the environment in order to achieve these values.

[0036] In another preferred use, the hydrogen thus produced is used for generating electricity in a fuel cell. Further preferred uses according to the invention can be found in the mobile sector (vehicles) and the stationary sector (industrial equipment).

[0037] A reforming catalyst substrate is produced by coating a flow-through substrate, for example composed of cordierite, with a coating medium containing Rh and containing Pt and / or Pd on a corresponding support oxide and subsequently subjecting it to a heat treatment, which produces hydrogen from hydrocarbons, in particular methane, in an oxygen-free reaction atmosphere containing a high water content and at elevated temperatures. Particularly effective in this case is an arrangement in which the noble metals are selected from the group consisting of Pt, Pd, and Rh, and M1 / M2 at the catalyst inlet is greater than M1 / M2 at the outlet, where M1 = Pt and / or Pd and M2 = Rh. This achieves an optimal balance between sufficient activity and the lowest possible noble metal price.

[0038] The reforming catalyst is long-term stable and still has sufficient activity to produce hydrogen even when continuous use is expected to exceed 50,000 hours and under very demanding conditions, even towards the end of its service life. Due to the endothermic reaction, there is a very strong temperature gradient within the reforming catalyst, which can be up to 200 °C under the expected application parameters. The reforming catalyst according to the invention manages to meet these requirements.

[0039] The drawings show:

[0040] Figure 1 : A preferred layout of the reforming catalyst according to the invention, which reforming catalyst comprises individual zones.

[0041] Figure 2 : Other conceivable embodiments of the reforming catalyst according to the invention: A mixture of Pt and Rh over the entire substrate monolith, where the M1 / M2 ratio varies according to the invention. Examples:

[0042] To produce the catalyst, a cordierite substrate from NGK (4.66" × 4.66" × 5.00", 4.3 / 300) was coated with a washcoat. Other flow-through substrates are also possible, in particular other flow-through substrates having different pore densities and wall thicknesses and also made of cordierite (e.g., 5.66" × 5.66" × 5.00", 4 / 400). Metal substrates can also be used. The catalytic activity is not substrate-dependent.

[0043] To produce the washcoat, first the support oxide (SCFa 110 from Sasol) and the AlO(OH) binder (Nyacol from Nyacol) AL20) Disperse them one by one in water. Subsequently, inject the precious metal solution. For the catalyst zone containing two precious metals, mix the platinum nitrate and rhodium nitrate solutions and dilute them with water before injection. After stirring for 30 minutes, adjust the pH value to >7, and grind the sizing primer in a circular form. The target particle size distribution has a d 50 value of 4.5 μm to 5.5 μm and a d 90 value of 10.6 μm to 14.8 μm.

[0044] Depending on the oxide-based solid content (which is ideally 33% to 36%), and according to the rheological properties of the sizing primer, nitric acid (HNO3), tetraethylammonium hydroxide (TEAH), or formic acid (HCOOH) can be used for adjustment to make it easier to coat.

[0045] Finally, clamp the substrate vertically in the holding device, and pump the sizing primer into the substrate from below to the required height, and then suck it out again. By weighing after the drying and calcination steps, determine any remaining mass and optionally recoat.

[0046] In an alternative coating method, apply the sizing primer to the vertically arranged substrate. By applying negative pressure, the sizing primer is then sucked through the substrate. By weighing after the drying and calcination steps, determine any remaining mass and recoat from the other side. In addition to this coating method, the required sizing primer can also be determined before coating, and corresponding to the optionally existing distinction, it can be divided into two halves and sucked into the substrate from both sides in two steps.

[0047] The last step is the heat treatment of the catalyst. After each coating step, dry at 100 °C to 120 °C and calcine at 350 °C for about 15 minutes, and then temper at 550 °C for 2 hours.

[0048] Prepare the following substrate blanks:

[0049] Example 1 - Inlet: 18.48 g / ft 3 Pt(1:0) Outlet: 18.52 g / ft 3 Pt, 9.77 g / ft 3 (1:1)

[0050] Example 2 - Inlet: 23.74 g / ft 3 Pt, 2.77 g / ft 3 Rh(4.52:1) Outlet: 13.26 g / ft 3 Pt, 7.0 g / ft 3 Rh(1:1)

[0051] Example 3 - Inlet: 2.0 g / ft3 Pt, 5.0 g / ft 3 Rh(0.21:1) Outlet: 35 g / ft 3 Pt, 4.77 g / ft 3 Rh(3.87:1)

[0052] Example 4 - Uniform Coating: 37 g / ft 3 Pt, 9.77 g / ft 3 Rh(2:1)

[0053] The examples for all zones are 30 / 70 zones.

[0054] For testing, 1"×3" cores were taken from the coated catalysts and their methane conversion was tested in an adiabatic quartz glass reactor.

[0055] The main reaction gas mixture for testing consisted of 5.9% CH4, 21.9% H2O, 1.8% CO, 12.9% CO2, 7.5% H2 and N2, balanced at a space velocity of 25,000 l / h. Measurements were started at a gas temperature of 150 °C. It was heated to a maximum of 700 °C at 10 K / min. When this maximum temperature was reached, the temperature was kept constant for another 30 minutes, after which the measurement ended. Finally, the mixture was cooled to 450 °C in the reaction gas atmosphere and then to room temperature in air.

[0056] Methane conversion is a measure of the catalyst activity and is calculated from the methane input concentration before conversion and the concentration at the highest reactor temperature.

[0057] In addition to testing the fresh catalyst, it was necessary to simulate catalyst aging in order to be able to evaluate the long-term stability and long-term activity. For this purpose, the produced catalyst cores were aged for about 50 hours at 850 °C in a permeation atmosphere of synthesis gas (3.3% H2, N2) and 44% H2O. The decrease in catalytic activity after aging is a measure of the long-term stability and long-term activity of the catalyst.

[0058] Measurement results (Table 2: Test catalyst with Pt:Rh = 2:1)

[0059]

[0060] *Front is 5 mm from the inlet of the substrate blank; rear is 5 mm from the end of the substrate blank; **Reference Example

[0061] As can be seen from the above table, according to Figure 1.The structure with a Pt:Rh ratio of 2:1 in a) produces the highest methane conversion before and after aging (Example 1). Generally, the methane conversion increases with the increase in the platinum content in the input region. At first glance, the methane conversion seems low because only small cores were tested instead of the full catalyst, but the amount of reaction gas is equivalent to about half of the gas amount that would pass through the full catalyst.

Claims

1. A substrate monolith comprising a reforming catalyst for producing hydrogen from hydrocarbons, in particular methane, said reforming catalyst comprising a noble metal and at least one support oxide on which the noble metal is deposited. It is characterized in that The noble metal is selected from the group consisting of Pt, Pd, and Rh, and M1 / M2 at the inlet region of the substrate monolith is greater than M1 / M2 at the other end, where M1 = Pt and / or Pd, and M2 = Rh.

2. The base stock according to claim 1, characterized in that, The support oxide comprises MgAl2O4 spinel, CeO2, and Al2O3.

3. The base stock according to claim 1 or claim 2, characterized in that, The substrate monolith does not contain any element selected from the group consisting of zirconium, chromium, and nickel.

4. The base stock according to claim 1, claim 2 or claim 3, characterized in that, The substrate monolith contains a binder.

5. The base stock according to any one of claims 1 to 4, characterized in that, The molar ratio of Pt to Rh is from 1:2 to 8:

1.

6. The base stock according to claim 5, characterized in that, The substrate monolith comprises at least two zones, and both zones contain Pt and Rh, and the front zone contains a higher concentration of Pt, while the rear zone contains a higher concentration of Rh.

7. A device for power generation, said device comprising the substrate monolith according to any one of claims 1 to 6 and a fuel cell in fluid contact therewith.

8. A method for preparing a substrate blank according to any one of claims 1 to 6, characterized in that, The substrate monolith is coated using a coating suspension comprising the components of the reforming catalyst in water, followed by drying and / or calcination, and finally tempered at a temperature of 400 °C to 600 °C for up to 6 hours.

9. Use of the substrate monolith according to any one of claims 1 to 6 for producing hydrogen from hydrocarbons.

10. The use according to claim 9, characterized in that, The use is carried out under adiabatic conditions.

11. Use of the catalyst according to claim 9 or claim 10, characterized in that, The hydrogen is produced from natural gas (CNG, LNG).

12. The use according to any one of claims 9 to 11, characterized in that, The hydrogen produced is used for power generation in a fuel cell.

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