A hydrogen catalyst for bio-ethanol reforming and a preparation method and application thereof

Abstract

The application provides a bio-ethanol reforming hydrogen catalyst, a preparation method and application thereof, and the bio-ethanol reforming hydrogen catalyst comprises a carrier and metal elements, wherein the metal elements comprise rhodium, lanthanum and cerium; in the bio-ethanol reforming hydrogen catalyst, the content of rhodium is 0.2-0.8 wt%, the content of lanthanum is 2-6 wt%, and the content of cerium is 5-12 wt%. The bio-ethanol reforming hydrogen catalyst has higher catalytic activity, catalytic stability and service life by mutual matching of element contents, and can be applied to large-scale bio-ethanol reforming hydrogen.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of renewable energy hydrogen production, and relates to a bio-ethanol reforming hydrogen production catalyst, a preparation method and application thereof. BACKGROUND

[0002] A large amount of pollutants and greenhouse gases such as carbon dioxide emitted in the process of energy production and use is one of the important sources of current environmental pollution. Therefore, it is necessary to find a clean and efficient energy to replace traditional energy. Hydrogen energy is a green renewable energy that can replace traditional energy, and the hydrogen production technology needs further research. Although bio-ethanol reforming hydrogen production can effectively produce hydrogen, it needs a catalyst with high activity and high selectivity to improve the efficiency of bio-ethanol reforming hydrogen production. Rhodium (Rh) is usually considered to be the most effective active component for bio-ethanol reforming hydrogen production due to its good C-C bond breaking ability.

[0003] For example, CN 102513105A discloses a cerium-based composite oxide supported noble metal catalyst for catalyzing alcohol and hydrocarbon low-temperature reforming to produce hydrogen. The cerium-lanthanum solid solution supported rhodium catalyst for hydrogen production comprises two parts: a noble metal and a carrier. The noble metal is one or a combination of two or more of rhodium, platinum, palladium, iridium, ruthenium and gold; and the carrier is a cerium-based composite oxide carrier represented by cerium-lanthanum solid solution. The catalyst can obtain good hydrogen production activity at a lower temperature. However, the catalyst is a powder catalyst and cannot be directly applied to large-scale industrial equipment.

[0004] For another example, CN 114160149A discloses a Cu-based catalyst for ethanol oxidative reforming to produce hydrogen, a preparation method and application thereof. The disclosed cerium-lanthanum solid solution supported copper catalyst also has good bio-ethanol reforming hydrogen production activity. In summary, the cerium-lanthanum solid solution has good active component dispersion ability, which is an important reason why the catalyst can obtain good reforming hydrogen production activity. However, after loading cerium-lanthanum mixed rare earth salt on the surface of alumina microspheres by impregnation, it is difficult to obtain a cerium-lanthanum solid solution with good uniformity as in homogeneous precipitation, but a cerium-lanthanum composite metal oxide. The core difference between the two is that the monolithic catalyst prepared by impregnation also presents a ceria fluorite cubic structure, but does not present obvious lattice expansion, and the lattice constant is not within the theoretical value range of cerium-lanthanum solid solution.

[0005] Therefore, most of the bio-ethanol reforming catalysts prepared in the prior art have poor stability and cannot truly adapt to the industrial application of bio-ethanol reforming hydrogen production. Moreover, the powder catalyst in the prior art is not sufficient to guide the development of monolithic catalysts, because the loading amount of cerium-lanthanum and other additives will significantly affect the specific surface area and acid-base properties of the catalyst, and there are more performance influencing factors compared with powder catalysts.

[0006] Based on the above research, it is necessary to provide a bio-ethanol reforming hydrogen catalyst, which has high catalytic activity, service life and stability, and can be applied to large-scale bio-ethanol reforming hydrogen production. SUMMARY

[0007] The purpose of the present application is to provide a bio-ethanol reforming hydrogen catalyst, its preparation method and application. The bio-ethanol reforming hydrogen catalyst is prepared by matching the elemental content, which controls the specific surface area and acid-base properties of the catalyst, so that the bio-ethanol reforming hydrogen catalyst has high catalytic activity, catalytic stability and service life, and can be applied to large-scale bio-ethanol reforming hydrogen production.

[0008] To achieve the purpose of the present application, the following technical solutions are adopted:

[0009] In a first aspect, the present application provides a bio-ethanol reforming hydrogen catalyst, which comprises a carrier and metal elements, wherein the metal elements include rhodium, lanthanum and cerium.

[0010] In the bio-ethanol reforming hydrogen catalyst, the content of rhodium is 0.2-0.8wt%, the content of lanthanum is 2-6wt%, and the content of cerium is 5-12wt%.

[0011] The content of lanthanum and cerium in the catalyst affects the specific surface area and acid-base degree of the catalyst, and the content of rhodium affects the catalytic activity of the catalyst, thereby affecting the catalytic performance. Therefore, based on the overall bio-ethanol reforming hydrogen catalyst, the rhodium, lanthanum and cerium are in a specific range, so that the catalyst can be used for large-scale bio-ethanol reforming, has high catalytic activity and catalytic service life, and can be stably applied for more than 1000 hours.

[0012] In the bio-ethanol reforming hydrogen catalyst, the content of rhodium is 0.2-0.8wt%, for example, it can be 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt% or 0.8wt%, but not limited to the listed values, other values not listed in the value range are also applicable, preferably 0.2-0.5wt%, further preferably 0.3-0.45wt%.

[0013] In the bio-ethanol reforming hydrogen catalyst, the content of lanthanum is 2-6wt%, for example, it can be 2wt%, 3wt%, 4wt%, 5wt% or 6wt%, and the content of cerium is 5-12wt%, for example, it can be 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt% or 12wt%, but not limited to the listed values, other values not listed in the value range are also applicable.

[0014] Preferably, the average particle size of the bio-ethanol reforming hydrogen catalyst is 0.3-0.5mm, for example, it can be 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm, but is not limited to the listed values, other values not listed in the value range are also applicable, preferably 0.38-0.45mm.

[0015] Preferably, the specific surface area of the bio-ethanol reforming hydrogen catalyst is 120-190m 2 / g, for example, it can be 130m 2 / g, 140m 2 / g, 150m 2 / g, 160m 2 / g, 170m 2 / g or 180m 2 / g, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0016] Preferably, the total content of lanthanum and cerium in the bio-ethanol reforming hydrogen catalyst is 12-18wt%, for example, it can be 13wt%, 14wt%, 15wt% or 17wt%, but is not limited to the listed values, other values not listed in the value range are also applicable, preferably 12.5-15wt%.

[0017] Preferably, the sum of the content of lanthanum and cerium and the specific surface area of the bio-ethanol reforming hydrogen catalyst satisfy the following relationship: y = b - ax, wherein, y is the specific surface area of the bio-ethanol reforming hydrogen catalyst, x is the sum of the content of lanthanum and cerium, a and b are coefficients.

[0018] In the above relationship of the present application, a>0, preferably 3-3.2, for example, it can be 3.0, 3.1 or 3.2, b>0, preferably 205-209, for example, it can be 206, 207, 208 or 209, R 2 is 0.98-0.999, for example, it can be 0.98, 0.99, 0.995 or 0.999, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0019] The sum of the content of lanthanum and cerium of the present application will affect the specific surface area of the catalyst as a whole, when the sum of the content of lanthanum and cerium and the specific surface area of the catalyst as a whole satisfy the above relationship, the performance of the catalyst can be further improved.

[0020] Preferably, the surface of the carrier comprises a metal catalytic layer, wherein the metal catalytic layer comprises rhodium, lanthanum and cerium, or the surface of the carrier comprises a first catalytic layer and a second catalytic layer stacked in sequence, wherein the first catalytic layer comprises rhodium, and the second catalytic layer comprises rhodium, lanthanum and cerium.

[0021] The metal elements of the present application are distributed on the surface of the carrier in two ways, one is that rhodium, lanthanum and cerium are all distributed on the surface of the carrier, and the other is that the carrier surface is first distributed with rhodium, and then rhodium, lanthanum and cerium are distributed. Among them, the layered distribution of metal elements can further improve the catalytic performance and play the synergistic effect of rhodium, lanthanum and cerium.

[0022] Preferably, in the first catalytic layer, the content of rhodium accounts for 20-40wt% of the total content of rhodium, for example, it can be 20wt%, 30wt% or 40wt%, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0023] Preferably, in the second catalytic layer, the content of rhodium accounts for 60-80wt% of the total content of rhodium, for example, it can be 60wt%, 70wt% or 80wt%, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0024] Preferably, the carrier comprises alumina.

[0025] Preferably, the metal elements exist in the form of oxides.

[0026] In a second aspect, the present application provides a preparation method of the biological ethanol reforming hydrogen catalyst as described in the first aspect, which comprises the following steps:

[0027] According to the formula amount, the rhodium source, the cerium source, the lanthanum source, the carrier and the solvent are mixed, the solvent is removed and calcined to obtain the biological ethanol reforming hydrogen catalyst.

[0028] Preferably, the mixing, removal of the solvent and calcination of the rhodium source, the cerium source, the lanthanum source, the carrier and the solvent comprises the following steps:

[0029] The rhodium salt, the cerium salt, the lanthanum salt and the solvent are mixed to obtain a mixed solution, the mixed solution is mixed with the carrier, and then the solvent is removed and calcined to obtain the biological ethanol reforming hydrogen catalyst.

[0030] The present application adopts the impregnation method to prepare a catalyst in which rhodium, cerium and lanthanum are uniformly distributed on the surface of the carrier. Metal salts that can be dissolved in solvent water are used. The rhodium salt, the cerium salt and the lanthanum salt are dissolved in water respectively, then mixed, the carrier is added after mixing, and finally steamed and calcined.

[0031] Preferably, the mixing, removal of the solvent and calcination of the rhodium source, the cerium source, the lanthanum source, the carrier and the solvent comprises the following steps:

[0032] (1) First, the rhodium oxide and the solvent are mixed to obtain a rhodium source slurry, then the rhodium source slurry is coated on the surface of the carrier, and then the solvent is removed and calcined to obtain a carrier loaded with a first catalytic layer;

[0033] (2) mixing rhodium oxide-containing, cerium oxide-containing, lanthanum oxide-containing and solvent to obtain mixed slurry, then coating the mixed slurry on the surface of the carrier with the first catalytic layer in step (1), and then removing the solvent and calcining to obtain the hydrogen catalyst for bio-ethanol reforming.

[0034] When the surface of the carrier of the catalyst of the present application comprises the first catalytic layer and the second catalytic layer which are stacked in sequence, the above preparation is used, and the slurry of the metal oxide and the solvent water is mixed with the carrier, so that the metal elements are distributed in different layers of the catalyst.

[0035] Preferably, the solid content of the rhodium source slurry in step (1) is 50-80wt%, for example, it can be 50wt%, 60wt%, 70wt% or 80wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0036] Preferably, the solid content of the mixed slurry in step (2) is 50-80wt%, for example, it can be 50wt%, 60wt%, 70wt% or 80wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0037] Preferably, the method for removing the solvent comprises evaporation to dryness.

[0038] Preferably, the temperature for evaporation to dryness is 80-100℃, for example, it can be 80℃, 90℃ or 100℃, and the time is 1-3h, for example, it can be 1h, 2h or 3h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0039] Preferably, the temperature for calcining is 500-700℃, for example, it can be 500℃, 600℃ or 700℃, and the time is 3-5h, for example, it can be 3h, 4h or 5h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0040] In a third aspect, the present application provides an application of the hydrogen catalyst for bio-ethanol reforming as described in the first aspect, and the application comprises large-scale hydrogen production from bio-ethanol reforming.

[0041] The catalyst of the present application can be applied to large-scale hydrogen production from bio-ethanol reforming, not only to small and medium-sized hydrogen production from bio-ethanol reforming, wherein the large-scale of the present application refers to hydrogen production of 200 standard cubic meters per hour.

[0042] Preferably, the method for the application comprises the following steps:

[0043] The hydrogen production from bio-ethanol reforming is loaded into a reactor, and vaporized ethanol, water and air are introduced, and then the temperature is raised for hydrogen production.

[0044] Preferably, the hydrogen production is the reducing agent.

[0045] The catalyst obtained by the application is simple to use and can be directly used, and the hydrogen generated by the reaction is used as the reducing agent.

[0046] Compared with the prior art, the application has the following beneficial effects:

[0047] The application is based on a whole bio-ethanol reforming hydrogen catalyst, and by allowing rhodium, lanthanum and cerium to be within a specific range, the catalyst can be used for large-scale bio-ethanol reforming, has high catalytic activity and catalytic life, and can make the life of the bio-ethanol reforming hydrogen catalyst reach more than 1000 hours. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 The figure shows the relationship between the Ce+La content and the specific surface area of the catalyst, the carrier and the carrier after calcination in the bio-ethanol reforming hydrogen catalyst.

[0049] Figure 2 The figure shows the relationship between the Rh content and the hydrogen yield under different mesh numbers in the bio-ethanol reforming hydrogen catalyst.

[0050] Figure 3 The figure shows the relationship between the Ce+La content and the hydrogen yield in the bio-ethanol reforming hydrogen catalyst. DETAILED DESCRIPTION

[0051] The technical solutions of the application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the application and should not be regarded as specific limitations on the application.

[0052] Embodiment 1

[0053] This embodiment provides a bio-ethanol reforming hydrogen catalyst, which comprises a carrier and a metal catalytic layer on the surface of the carrier, wherein the metal catalytic layer comprises rhodium, lanthanum and cerium, the carrier is Al2O3, and the rhodium, lanthanum and cerium exist in the form of oxides.

[0054] In the bio-ethanol reforming hydrogen catalyst, the content of rhodium is 0.4wt%, the content of lanthanum is 4wt%, the content of cerium is 9.5wt%, and the total content of lanthanum and cerium is 13.5wt%.

[0055] The average particle size of the bio-ethanol reforming hydrogen catalyst is 0.4mm, and the specific surface area is 165m 2 / g, the sum of the content of lanthanum and cerium and the specific surface area of the bio-ethanol reforming hydrogen catalyst satisfies the following relationship: y = 207-3.1x, y is the specific surface area of the bio-ethanol reforming hydrogen catalyst (m 2 / g), x is the sum of the content of lanthanum and cerium (wt.%), R 2 = 0.985.

[0056] The preparation method of the bio-ethanol reforming hydrogen catalyst comprises the following steps:

[0057] (1) 160 g (calculated as Rh) of rhodium nitrate solution, 2000 g of cerium nitrate and 1000 g of lanthanum nitrate are respectively dissolved to form a mixed solution of 4 L;

[0058] (2) 5000 g of Al2O3 microspheres and the mixed solution of step (1) are mixed, stirred uniformly, then dried in an oven at 90°C for 2 h, and then calcined at 600°C for 4 h to obtain the bio-ethanol reforming hydrogen catalyst.

[0059] Example 2

[0060] The present embodiment provides a bio-ethanol reforming hydrogen catalyst, which comprises a carrier and a metal catalytic layer on the surface of the carrier, wherein the metal catalytic layer comprises rhodium, lanthanum and cerium, the carrier is Al2O3, and the rhodium, lanthanum and cerium exist in the form of oxides;

[0061] In the bio-ethanol reforming hydrogen catalyst, the content of rhodium is 0.3 wt.%, the content of lanthanum is 3 wt.%, the content of cerium is 12 wt.%, and the total content of lanthanum and cerium is 15 wt.%.

[0062] The average particle size of the bio-ethanol reforming hydrogen catalyst is 0.38 mm, the specific surface area is 160 m 2 / g, the sum of the content of lanthanum and cerium and the specific surface area of the bio-ethanol reforming hydrogen catalyst satisfies the following relationship: y = 207-3.1x, y is the specific surface area of the bio-ethanol reforming hydrogen catalyst, x is the sum of the content of lanthanum and cerium, R 2 = 0.985.

[0063] The preparation method of the bio-ethanol reforming hydrogen catalyst comprises the following steps:

[0064] (1) rhodium nitrate solution, cerium nitrate and lanthanum nitrate are respectively dissolved to form a mixed solution;

[0065] (2) Al2O3 microspheres and the mixed solution of step (1) are mixed, stirred uniformly, then dried in an oven at 80°C for 3 h, and then calcined at 500°C for 5 h to obtain the bio-ethanol reforming hydrogen catalyst.

[0066] Embodiment 3

[0067] The embodiment provides a bio-ethanol reforming hydrogen catalyst, which comprises a carrier and a metal catalytic layer on the surface of the carrier, wherein the metal catalytic layer comprises rhodium, lanthanum and cerium, the carrier is Al2O3, and the rhodium, the lanthanum and the cerium are in the form of oxides;

[0068] In the bio-ethanol reforming hydrogen catalyst, the content of the rhodium is 0.45 wt%, the content of the lanthanum is 6 wt%, the content of the cerium is 6 wt%, and the total content of the lanthanum and the cerium is 12 wt%;

[0069] The average particle size of the bio-ethanol reforming hydrogen catalyst is 0.45 mm, the specific surface area is 170 m 2 / g, and the sum of the contents of the lanthanum and the cerium and the specific surface area of the bio-ethanol reforming hydrogen catalyst satisfy the following relationship: y = 207-3.1x, wherein y is the specific surface area of the bio-ethanol reforming hydrogen catalyst, x is the sum of the contents of the lanthanum and the cerium, and R 2 = 0.985;

[0070] The preparation method of the bio-ethanol reforming hydrogen catalyst comprises the following steps:

[0071] (1) rhodium nitrate solution, cerium nitrate and lanthanum nitrate are respectively dissolved, and the mixed solution is prepared;

[0072] (2) Al2O3 microspheres and the mixed solution in step (1) are mixed, uniformly stirred, dried in an oven at 100 DEG C for 1 h, and then calcined at 700 DEG C for 3 h to obtain the bio-ethanol reforming hydrogen catalyst.

[0073] Embodiment 4

[0074] The embodiment provides a bio-ethanol reforming hydrogen catalyst, which is the same as that in Embodiment 1 except that the distribution modes of rhodium, lanthanum and cerium are different from those in Embodiment 1;

[0075] Specifically, the catalyst in the embodiment comprises a carrier and a first catalytic layer and a second catalytic layer which are sequentially arranged on the surface of the carrier, wherein the first catalytic layer comprises rhodium, the second catalytic layer comprises rhodium, lanthanum and cerium, the content of the rhodium in the first catalytic layer accounts for 40 wt% of the total content of the rhodium, and the content of the rhodium in the second catalytic layer accounts for 60 wt% of the total content of the rhodium;

[0076] The preparation method of the bio-ethanol reforming hydrogen catalyst in the embodiment comprises the following steps:

[0077] (1) first mix rhodium oxide and water to obtain a rhodium source slurry with a solid content of 80wt%, then coat the rhodium source slurry on the surface of the carrier, then dry in an oven at 100℃ for 1h, then calcine at 700℃ for 3h to obtain the carrier loaded with the first catalytic layer;

[0078] (2) mix rhodium oxide, cerium oxide, lanthanum oxide and water to obtain a mixed slurry with a solid content of 50wt%, then coat the mixed slurry on the surface of the carrier loaded with the first catalytic layer in step (1), then dry in an oven at 100℃ for 3h, then calcine at 500℃ for 3h to obtain the bio-ethanol reforming hydrogen production catalyst.

[0079] Example 5

[0080] The bio-ethanol reforming hydrogen production catalyst provided in the embodiment is the same as that in Example 1 except that the distribution modes of rhodium, lanthanum and cerium are different from those in Example 1.

[0081] Specifically, the catalyst in the embodiment comprises a carrier and a first catalytic layer and a second catalytic layer sequentially stacked on the surface of the carrier, wherein the first catalytic layer comprises rhodium, and the second catalytic layer comprises rhodium, lanthanum and cerium, the content of rhodium in the first catalytic layer accounts for 20wt% of the total content of rhodium, and the content of rhodium in the second catalytic layer accounts for 80wt% of the total content of rhodium.

[0082] The preparation method of the bio-ethanol reforming hydrogen production catalyst in the embodiment comprises the following steps:

[0083] (1) first mix rhodium oxide and water to obtain a rhodium source slurry with a solid content of 50wt%, then coat the rhodium source slurry on the surface of the carrier, then dry in an oven at 80℃ for 3h, then calcine at 500℃ for 5h to obtain the carrier loaded with the first catalytic layer;

[0084] (2) mix rhodium oxide, cerium oxide, lanthanum oxide and water to obtain a mixed slurry with a solid content of 80wt%, then coat the mixed slurry on the surface of the carrier loaded with the first catalytic layer in step (1), then dry in an oven at 100℃ for 1h, then calcine at 700℃ for 3h to obtain the bio-ethanol reforming hydrogen production catalyst.

[0085] Example 6

[0086] The bio-ethanol reforming hydrogen production catalyst provided in the embodiment is the same as that in Example 1 except that the content of rhodium is 0.2wt%.

[0087] Example 7

[0088] The present example provides a bio-ethanol reforming hydrogen catalyst, wherein the content of rhodium is 0.5 wt%, and the rest is the same as example 1.

[0089] Example 8

[0090] The present example provides a bio-ethanol reforming hydrogen catalyst, wherein the content of rhodium is 0.8 wt%, and the rest is the same as example 1.

[0091] Example 9

[0092] The present example provides a bio-ethanol reforming hydrogen catalyst, wherein the content of lanthanum is 2.5 wt%, the total content of lanthanum and cerium is 12 wt%, and the specific surface area of the catalyst is adaptively changed, and the rest is the same as example 1.

[0093] Example 10

[0094] The present example provides a bio-ethanol reforming hydrogen catalyst, wherein the content of lanthanum is 6 wt%, the content of cerium is 12 wt%, the total content of lanthanum and cerium is 18 wt%, and the specific surface area of the catalyst is adaptively changed, and the rest is the same as example 1.

[0095] Example 11

[0096] The present example provides a bio-ethanol reforming hydrogen catalyst, wherein the content of cerium is 6.5 wt%, the total content of lanthanum and cerium is 10.5 wt%, and the specific surface area of the catalyst is adaptively changed, and the rest is the same as example 1.

[0097] Example 12

[0098] The present example provides a bio-ethanol reforming hydrogen catalyst, wherein the content of lanthanum is 2 wt%, the content of cerium is 5 wt%, the total content of lanthanum and cerium is 7 wt%, and the specific surface area of the catalyst is adaptively changed, and the rest is the same as example 1.

[0099] Comparative Example 1

[0100] The present comparative example provides a bio-ethanol reforming hydrogen catalyst, wherein the content of rhodium is 0.1 wt%, and the rest is the same as example 1.

[0101] Comparative Example 2

[0102] The comparative example 2 provides a bio-ethanol reforming hydrogen catalyst, which is the same as the example 1 except that the content of rhodium is 1 wt% and the content of cerium is 4 wt% so that the total content of rhodium and cerium is 5 wt%.

[0103] Comparative example 3

[0104] The comparative example 4 provides a bio-ethanol reforming hydrogen catalyst, which is the same as the example 1 except that the content of lanthanum is 7 wt% and the content of cerium is 13 wt% so that the total content of lanthanum and cerium is 20 wt% and the specific surface area of the catalyst is changed adaptively.

[0105] Comparative example 4

[0106] The comparative example 4 provides a bio-ethanol reforming hydrogen catalyst, which is the same as the example 1 except that the content of lanthanum is 7 wt% and the content of cerium is 13 wt% so that the total content of lanthanum and cerium is 20 wt% and the specific surface area of the catalyst is changed adaptively.

[0107] The bio-ethanol reforming hydrogen catalysts obtained in the above examples and comparative examples are loaded into a tube reactor, and ethanol and water (flow rate of 230 kg / h) vaporized at 200°C and air (flow rate of 5 Nm 3 / h) are introduced into the tube reactor, the molar ratio of the ethanol and water is 1:7, the reaction temperature is increased to 600°C after being kept at 200°C for 2 h, and hydrogen production is carried out, the hydrogen purity in the produced reforming gas and the hydrogen yield are shown in Table 1, and the catalyst life of the above examples and comparative examples in large-scale bio-ethanol reforming hydrogen production is shown in Table 1.

[0108] Table 1

[0109]

[0110]

[0111] It can be seen from Table 1 that:

[0112] The present application can obtain a monolithic catalyst for large-scale bio-ethanol reforming hydrogen production with excellent catalytic performance by controlling the content of rhodium, cerium and lanthanum, and the catalyst life can reach more than 1000 h; as can be seen from the example 1 and examples 4-5, the catalytic effect can be further improved when the different metals are distributed in different catalytic layers; as can be seen from examples 6-11, the total content of rhodium, cerium and lanthanum in a specific range can further improve the catalytic performance.

[0113] Meanwhile, to investigate the relationship between lanthanum and cerium and the specific surface area of ​​the catalyst, this invention studies the change in specific surface area by varying the total Ce and La content in the catalyst. The relationship between Ce+La content and the specific surface area of ​​the catalyst, support, and the support after calcination is shown in the figure below. Figure 1 As shown, CLA# represents the Ce-La-Al support (where Ce-La-Al homogeneous oxide exists), and linear fitting yields y = 214 - 3.1x, R0 2 =0.981; Rh / CLA# refers to Rh loaded on the Ce-La-Al oxide surface, linear fitting yields y = 207 - 3.1x, R 2 =0.985; CLA* is the calcined CLA#, and linear fitting yields y = 181 - 2.9x, R0 2 =0.998, from Figure 1 It can be seen that increasing the total amount of cerium and lanthanum will lead to a decrease in the specific surface area of ​​the catalyst; the relationship between Rh content and hydrogen yield of the bioethanol reforming hydrogen production catalyst of this invention at different mesh sizes is shown in the figure below. Figure 2 As shown, CL (wt%) = 16 ± 1.6 refers to the total content of lanthanum and cerium, H / E = 6.4 refers to the water / ethanol ratio of 6.4, and O / E = 0.2 refers to the oxygen / ethanol ratio of 0.2. Figure 2 It is known that changes in Rh content affect hydrogen yield, and that a higher rhodium content does not necessarily lead to a higher hydrogen yield. The relationship between Ce+La content and hydrogen yield in the bioethanol reforming hydrogen production catalyst described in this invention is shown in the following graph. Figure 3 As shown, Rh (wt%) = 0.37 ± 0.3 refers to the Rh content, H / E = 6.4 refers to the water / ethanol ratio of 6.4, and O / E = 0.2 refers to the oxygen / ethanol ratio of 0.2. Figure 3 It can be seen that changes in the total content of lanthanum and cerium will affect the hydrogen yield.

[0114] In summary, this invention provides a bioethanol reforming hydrogen production catalyst, its preparation method, and its application. The bioethanol reforming hydrogen production catalyst, through the mutual matching of element contents, regulates the specific surface area and acidity / alkalinity of the catalyst, thereby enabling the bioethanol reforming hydrogen production catalyst to possess high catalytic activity, catalytic stability, and lifespan, and can be applied to large-scale bioethanol reforming hydrogen production.

[0115] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A catalyst for hydrogen production by reforming bioethanol, characterized by, The bio-ethanol reforming hydrogen catalyst comprises a carrier and metal elements, and the metal elements comprise rhodium, lanthanum and cerium; In the bio-ethanol reforming hydrogen catalyst, the content of rhodium is 0.4-0.45wt%, the content of lanthanum is 2-6wt%, the content of cerium is 5-12wt%, and the total content of lanthanum and cerium is 12.5-14wt%. The surface of the carrier comprises a first catalytic layer and a second catalytic layer which are stacked in sequence, wherein the first catalytic layer comprises rhodium, and the second catalytic layer comprises rhodium, lanthanum and cerium; In the first catalytic layer, the content of rhodium accounts for 20-40wt% of the total content of rhodium. In the second catalytic layer, the content of rhodium accounts for 60-80wt% of the total content of rhodium.

2. The bio-ethanol reforming hydrogen catalyst according to claim 1, wherein, The average particle size of the bio-ethanol reforming hydrogen catalyst is 0.3-0.5mm.

3. The bio-ethanol reforming hydrogen catalyst according to claim 2, wherein, The average particle size of the bio-ethanol reforming hydrogen catalyst is 0.38-0.45mm.

4. The bio-ethanol reforming hydrogen catalyst according to claim 1, wherein, The specific surface area of the bio-ethanol reforming hydrogen catalyst is 120-190 m 2 / g.

5. The bio-ethanol reforming catalyst for hydrogen production according to claim 1, wherein The sum of the contents of lanthanum and cerium and the specific surface area of the bio-ethanol reforming hydrogen catalyst satisfy the following relationship: y=b-ax, wherein y is the specific surface area of the bio-ethanol reforming hydrogen catalyst, x is the sum of the contents of lanthanum and cerium, and a and b are coefficients.

6. The bio-ethanol reforming catalyst for hydrogen production according to claim 1, wherein The carrier comprises alumina.

7. The bio-ethanol reforming hydrogen catalyst according to claim 1, wherein, The metal elements exist in the form of oxides.

8. A method for preparing a catalyst for hydrogen production by reforming bioethanol according to any one of claims 1 to 7, characterized in that, The preparation method comprises the following steps: According to the formula, the rhodium source, the cerium source, the lanthanum source, the carrier and the solvent are mixed, the solvent is removed, and the bio-ethanol reforming hydrogen catalyst is obtained by calcination, which comprises the following steps: (1) First, the rhodium oxide-containing and the solvent are mixed to obtain a rhodium source slurry, then the rhodium source slurry is coated on the surface of the carrier, and then the solvent is removed and calcined to obtain a carrier loaded with a first catalytic layer; (2) The rhodium oxide-containing, the cerium oxide-containing, the lanthanum oxide-containing and the solvent are mixed to obtain a mixed slurry, then the mixed slurry is coated on the surface of the carrier loaded with the first catalytic layer in step (1), and then the solvent is removed and calcined to obtain the bio-ethanol reforming hydrogen catalyst.

9. The preparation method according to claim 8, characterized in that, The solid content of the rhodium source slurry in step (1) is 50-80wt%.

10. The preparation method according to claim 8, characterized in that, The solid content of the mixed slurry in step (2) is 50-80wt%.

11. The preparation method according to claim 8, characterized in that, The method for removing the solvent comprises evaporation to dryness.

12. The method of claim 11, wherein, The temperature for evaporation to dryness is 80-100℃, and the time is 1-3h.

13. The preparation method according to claim 8, characterized in that, The calcination temperature is 500-700℃, and the time is 3-5h.

14. Use of a catalyst for the reforming of bioethanol to produce hydrogen according to any one of claims 1 to 7, wherein the catalyst is used in a process for the production of hydrogen from bioethanol. The application comprises large-scale bio-ethanol reforming hydrogen production.

15. Use according to claim 14, characterized in that, The method for application comprises the following steps: The bio-ethanol reforming hydrogen is loaded into a reactor, vaporized ethanol, water and air are introduced, and then the temperature is raised for hydrogen production.

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