CN113209976B - A kind of catalyst for hydrogen production by methanol steam reforming, its preparation method and application, and methanol steam reforming hydrogen production reaction - Google Patents

Abstract

The invention belongs to the technical field of energy and chemical industry, and provides a catalyst for hydrogen production by methanol steam reforming, a preparation method and application thereof, and a reaction for hydrogen production by methanol steam reforming. The catalyst provided by the present invention comprises an oxide support and copper oxide and fullerene C ₆₀ supported on the oxide support. Fullerene C ₆₀ has excellent electron acceptor properties, can reversibly capture and release electrons, can effectively adjust the electrons on the copper surface, and control the equilibrium distribution and stability of copper valence states, thereby ensuring the stability of the catalyst. The catalyst provided by the invention, under the conditions that the temperature is 240 DEG C, the pressure is 0.1 MPa, the molar ratio of water and methanol is 1.2:1, and the mass space velocity of methanol is 4.5h- ¹ , the hydrogen production rate is 0.4mol/g/ h, the CO selectivity was lower than 0.3%, and the structure and properties remained stable after 200 h of continuous reaction without deactivation.

Description

A kind of catalyst for hydrogen production by methanol steam reforming and its preparation method and application, reaction for hydrogen production by methanol steam reforming

technical field

The present invention relates to energy chemical technology

The field, in particular, relates to a catalyst for hydrogen production by methanol steam reforming, a preparation method and application thereof, and a reaction for hydrogen production by methanol steam reforming.

Background technique

Hydrogen energy is regarded as the clean energy with the most development potential in this century, and it is an important research object of energy storage and conversion. The hydrogen production technology of methanol steam reforming has attracted widespread attention due to its advantages such as safe and easy availability of raw materials, low reaction temperature, and few by-products. The use of methanol and steam reforming can be used for on-site hydrogen production to provide hydrogen source for fuel cells, which not only solves the problem of difficult hydrogen transportation, but also has certain advantages in terms of safety and economy.

The key to hydrogen production technology from methanol steam reforming is focused on efficient and stable catalyst preparation and reactor design. Among them, catalysts for hydrogen production from methanol steam reforming need to take into account many factors such as raw material cost, reaction space velocity and temperature, methanol conversion rate, and by-product CO selectivity. At present, the catalysts used for hydrogen production from methanol steam reforming mainly include noble metal platinum-palladium-based and copper-based catalysts. Among them, although the platinum-palladium-based catalyst has good stability and high activity, the cost is too high; at the same time, the reforming temperature of the platinum-palladium-based catalyst can reach 300-500 °C to achieve better methanol activation and conversion. Although copper-based catalysts have obvious low-temperature activity, they often need to be reformed in the range of 260-300 °C. At the same time, the most fatal problem of copper-based catalysts is the poor stability, especially the rapid deactivation caused by the imbalance of the surface valence state; the valence state of Cu itself is changeable, and Cu (Cu ⁰ and Cu+) and synergistic effect can maintain the efficient and stable activation of the substrate; the production of CO and the high-temperature reducing atmosphere are not conducive to the stability of copper-based catalysts.

Therefore, most of the current research is on modified copper-based catalysts. Yang Shuqian et al. (Journal of Fuel Chemistry [J], 2018, 46, 179-188) studied the effect of rare earth (lanthanum, cerium, samarium and gadolinium, etc.) doping on the catalytic performance of copper-zinc-aluminum hydrotalcite-derived catalysts. The results show that: rare earth elements The introduction of copper can improve the dispersion, specific surface area and reducing properties of the active component copper, thereby improving the catalytic activity of the catalyst.

Although many modified copper-based catalysts have improved a lot compared to traditional copper-based catalysts, there is still a problem of poor stability.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a catalyst for hydrogen production by methanol steam reforming, a preparation method and application thereof, and a reaction for hydrogen production by methanol steam reforming. The catalyst provided by the present invention has excellent stability.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

The invention provides a catalyst for hydrogen production by methanol steam reforming, comprising an oxide carrier and an active component supported on the oxide carrier; the active component includes copper oxide and fullerene C ₆₀ ; the The oxide support includes one or more of zinc oxide, alumina, zirconia, ceria, and silica.

Preferably, in the catalyst for hydrogen production by methanol steam reforming, the mass percentage of the copper oxide is 10-60%; the mass percentage of fullerene C ₆₀ is 1-30%, and the balance for the oxide carrier.

The present invention also provides the preparation method of the catalyst for hydrogen production by methanol steam reforming described in the above technical solution, comprising the following steps:

First mixing the soluble copper salt, the water-soluble salt corresponding to the oxide carrier, the fullerene C ₆₀ and water to obtain a first mixed solution;

mixing the first mixed solution and the precipitant aqueous solution in parallel, and aging to obtain a coprecipitate;

The coprecipitate is calcined to obtain the catalyst for hydrogen production by methanol steam reforming.

The present invention also provides another method for preparing a catalyst for hydrogen production by methanol steam reforming as described in the above technical solution, comprising the following steps:

The soluble copper salt, oxide carrier, fullerene C ₆₀ and water are mixed for a second time to obtain a second mixed solution;

adding the precipitant aqueous solution to the second mixed solution, and performing aging to obtain a deposition precipitate;

The deposited precipitate is calcined to obtain the catalyst for hydrogen production by methanol steam reforming.

Preferably, the aqueous solution of the precipitating agent is ammonia water or an aqueous alkaline solution; the mass concentration of the aqueous ammonia is 26-28%; the alkaline substances in the aqueous alkaline solution are urea, sodium carbonate, potassium carbonate, and sodium hydroxide or potassium hydroxide.

Preferably, the aging temperature is 30-120° C., and the time is 6-24 h; the aging is performed under stirring conditions, and the stirring speed is 200-900 r/min.

Preferably, the calcining temperature is 250-350° C., and the time is 1-12 h; the calcining atmosphere is air.

The present invention also provides the catalyst for hydrogen production by methanol steam reforming described in the above technical solution or the catalyst for hydrogen production by methanol steam reforming obtained by the preparation method described in the above technical solution in the catalytic reaction of methanol steam reforming for hydrogen production applications in .

The present invention also provides a methanol steam reforming hydrogen production reaction, comprising the following steps:

reducing the catalyst for hydrogen production by methanol steam reforming described in the above technical solution or the catalyst for hydrogen production by methanol steam reforming obtained by the preparation method described in the above technical solution, to obtain a reduced catalyst;

Under the condition of a reduced catalyst, methanol and water undergo a hydrogen production reaction to obtain hydrogen;

The reducing atmosphere is hydrogen, the temperature is 250-350 DEG C, and the time is 1-12 h.

Preferably, the conditions for the hydrogen production reaction include: a temperature of 220 to 260° C., a pressure of 0.1 to 1.0 MPa, a molar ratio of water to methanol of 0.9 to 1.5:1, and a mass space velocity of methanol of 3 to 6 h ⁻¹ .

The invention provides a catalyst for hydrogen production by methanol steam reforming, comprising an oxide carrier and an active component supported on the oxide carrier; the active component includes copper oxide and fullerene C ₆₀ ; the The oxide support includes one or more of zinc oxide, alumina, zirconia, ceria, and silica. In the present invention, fullerene C ₆₀ , as a carbon element material with clear structure and unique properties, has excellent electron acceptor properties, can reversibly capture and release electrons, can effectively regulate copper surface electrons, and control copper valence states The equilibrium distribution and stability of the catalyst ensure the stability of the catalyst.

The present invention also provides the preparation method of the catalyst for hydrogen production by methanol steam reforming as described in the above technical solution, which is prepared by the co-precipitation method and the deposition precipitation method respectively; the preparation method provided by the present invention has wide source of raw materials, simple operation and low cost. lower.

The present invention also provides the catalyst for hydrogen production by methanol steam reforming described in the above technical solution or the catalyst for hydrogen production by methanol steam reforming obtained by the preparation method described in the above technical solution in the catalytic reaction of methanol steam reforming for hydrogen production When the catalyst of the present invention is used in the hydrogen production reaction of methanol steam reforming, the reaction temperature is low, the catalytic effect is good, the hydrogen production rate is high and the service life is long.

The data of the examples show that: when the catalyst provided by the present invention is used to catalyze the hydrogen production reaction of methanol steam reforming, the temperature is 240° C., the pressure is 0.1 MPa, the molar ratio of water and methanol is 1.2:1, and the mass space velocity of methanol is 1.2:1. Under the condition of 4.5h ^-1 , the hydrogen production rate is 0.4mol/g/h, and the CO selectivity is lower than 0.3%. The structure and performance remain stable after 200h of continuous reaction, and there is no deactivation phenomenon.

Description of drawings

Fig. 1 is the service life test diagram of the catalyst obtained in Example 1 of the present invention used in the reaction of methanol steam reforming for hydrogen production;

Fig. 2 is the X-ray powder diffraction pattern of the catalyst for hydrogen production by methanol steam reforming obtained in Example 1 of the present invention and Comparative Example 1;

3 is a transmission electron microscope photograph of the catalyst for hydrogen production by methanol steam reforming obtained in Example 1 of the present invention.

Detailed ways

The invention provides a catalyst for hydrogen production by methanol steam reforming, comprising an oxide carrier and an active component supported on the oxide carrier; the active component includes copper oxide and fullerene C ₆₀ ; the The oxide support includes one or more of zinc oxide, alumina, zirconia, ceria, and silica.

The catalyst for hydrogen production by methanol steam reforming provided by the present invention comprises an oxide carrier. In the present invention, the oxide support includes one or more of zinc oxide, aluminum oxide, zirconium oxide, ceria and silicon dioxide.

The catalyst for hydrogen production by methanol steam reforming provided by the present invention includes active components supported on the oxide carrier. In the present invention, the active ingredients include copper oxide and fullerene C ₆₀ . In the present invention, the copper oxide and fullerene C ₆₀ are supported on the oxide carrier in the form of nanoparticles and nanoclusters.

In the present invention, in the catalyst for hydrogen production by methanol steam reforming, the mass percentage content of the copper oxide is preferably 10-60%, more preferably 20-50%. In the present invention, in the catalyst for hydrogen production by methanol steam reforming, the mass percentage content of the fullerene C ₆₀ is preferably 1% to 30%, more preferably 5 to 20%. In the present invention, the catalyst for hydrogen production by methanol steam reforming includes the balance of oxide supports.

In the present invention, fullerene C ₆₀ , as a carbon element material with clear structure and unique properties, has excellent electron acceptor properties, can reversibly capture and release electrons, can effectively regulate copper surface electrons, and control copper valence states The equilibrium distribution and stability of the catalyst ensure the stability of the catalyst.

The present invention also provides the preparation method of the catalyst for hydrogen production by methanol steam reforming described in the above technical solution, comprising the following steps:

Mixing the soluble copper salt, the water-soluble salt corresponding to the oxide carrier, the fullerene C ₆₀ and water to obtain a first mixed solution;

mixing the first mixed solution and the precipitant aqueous solution in parallel, and aging to obtain a coprecipitate;

The coprecipitate is calcined to obtain the catalyst for hydrogen production by methanol steam reforming.

In the present invention, unless otherwise specified, the raw materials used in the present invention are preferably commercially available products.

In the present invention, the soluble copper salt, the water-soluble salt corresponding to the oxide carrier, the fullerene C ₆₀ and water are mixed to obtain the first mixed solution.

In the present invention, the soluble copper salt is preferably one or more of copper nitrate, copper sulfate, copper acetate and copper chloride, more preferably copper nitrate or copper acetate, more preferably copper nitrate.

In the present invention, the water-soluble salt corresponding to the oxide carrier preferably includes: when the oxide carrier is zinc oxide, the water-soluble salt corresponding to zinc oxide preferably includes zinc sulfate, zinc chloride, zinc nitrate and zinc acetate one or more of aluminum oxide; when the oxide is aluminum oxide, the water-soluble salt corresponding to the aluminum oxide preferably includes one or more of aluminum chloride, aluminum sulfate, aluminum nitrate and aluminum acetate; the oxide When the carrier is zirconium oxide, the metal salt corresponding to the zirconium oxide preferably includes one or more of zirconium chloride, zirconium nitrate, zirconium sulfate and zirconium acetate; when the oxide carrier is cerium oxide, the cerium oxide The corresponding water-soluble salt preferably includes one or more of cerium chloride, cerium nitrate, cerium sulfate and cerium acetate; when the oxide carrier is silica, the water-soluble salt corresponding to the silica preferably includes One or more of silica sol, silicon tetrachloride, tetramethyl silicate and tetraethyl silicate.

In the present invention, the particle size of the fullerene C ₆₀ is preferably 0.7-20 nm; the purity of the fullerene C ₆₀ is preferably 95-99.99%, more preferably 98-99.99%, and most preferably 99-99%. 99.99%; the fullerene C ₆₀ contains trace amounts of C ₇₀ and other fullerenes. In the present invention, the fullerene C ₆₀ is a hollow spherical molecule composed of 60 carbon atoms, and is a black or brown powder, which is mainly prepared and purified by a combustion method and an arc method.

In the present invention, the water is preferably deionized water.

In the present invention, the order of the first mixing preferably includes:

Mixing the water-soluble copper salt, the water-soluble salt corresponding to the oxide carrier and water to obtain a salt solution;

The fullerene C ₆₀ and water are ultrasonically stirred and mixed to obtain a dispersion solution of C ₆₀ ;

The salt solution and the dispersed solution of C ₆₀ are mixed with ultrasonic stirring to obtain the first mixed solution.

In the present invention, in the salt solution, the concentration of the water-soluble copper salt is preferably 0.05-0.6 mol/L, more preferably 0.1-0.3 mol/L; the concentration of the water-soluble salt corresponding to the oxide carrier is preferably 0.1-2 mol /L, more preferably 0.2 to 1 mol/L.

In the present invention, the concentration of the C ₆₀ dispersion solution is preferably 10 to 15 mg/mL, and more preferably 12 mg/mL.

In the present invention, the volume ratio of the salt solution and the dispersion solution of C ₆₀ is preferably 4:1.

In the present invention, the power of the ultrasonic wave in the ultrasonic stirring is preferably 20-60W, more preferably 40W; the stirring speed in the ultrasonic stirring is preferably 200-900 r/min, more preferably 400-800 r/min. In the present invention, the ultrasonic stirring time is preferably 20-45 min, more preferably 30 min. The present invention has no special requirements on the equipment used for ultrasonic stirring, and equipment well known to those skilled in the art can be used. The method of ultrasonic stirring can ensure the uniform dispersion and close contact of each component in the solution.

After the first mixed solution is obtained, the present invention mixes the first mixed solution and the aqueous solution of the precipitant in a co-current flow, and performs aging to obtain a coprecipitate.

In the present invention, the aqueous solution of the precipitant is preferably aqueous ammonia or an aqueous alkaline solution; the mass concentration of the aqueous ammonia is preferably 26-28%. In the present invention, the concentration of the aqueous alkaline solution is preferably 0.1 to 3 mol/L, more preferably 0.2 to 1.5 mol/L. In the present invention, the alkaline substance in the alkaline substance aqueous solution is preferably urea, sodium carbonate, potassium carbonate, sodium hydroxide or potassium hydroxide, more preferably sodium carbonate or potassium carbonate, more preferably sodium carbonate.

In the present invention, the flow rate of the first mixed solution is preferably 3-12 mL/min, more preferably 6-8 mL/min; the flow rate of the precipitant aqueous solution is preferably 3-12 mL/min, more preferably 6-8 mL/min 8mL/min.

In the present invention, the aging temperature is preferably 30-120°C, more preferably 50-90°C, more preferably 60-70°C; the time is preferably 1-12h, more preferably 2-8h, more preferably 3 to 5 hours. In the present invention, the aging is preferably performed under stirring conditions, and the rotational speed of the stirring is preferably 200-900 r/min, more preferably 400-800 r/min.

After the aging, the present invention preferably further includes performing solid-liquid separation on the obtained aging system, and sequentially washing and drying the obtained solid.

In the present invention, the solid-liquid separation method is preferably filtration, and the present invention does not specifically limit the operation of the filtration, and a filtration means well-known to those skilled in the art may be used.

In the present invention, the temperature of the washing is preferably room temperature; the washing preferably includes washing with water and washing with ethanol in sequence. In the present invention, the number of times of the water washing is preferably 2 to 3 times. The present invention does not specifically limit the amount of the reagent for the water washing, as long as the solid can be washed with water. In the present invention, the number of times of the ethanol washing is preferably one time, and the present invention does not specifically limit the amount of the reagent for the ethanol washing, as long as it can be washed cleanly.

In the present invention, the drying temperature is preferably 80-120°C, more preferably 90-110°C, more preferably 100°C; the time is preferably 6-24h, more preferably 8-16h, more preferably 10- 14h. In the present invention, the drying is preferably performed in an air atmosphere. The present invention has no special requirements on the equipment used for the drying, and equipment well known to those skilled in the art may be used. In the embodiment of the present invention, the drying equipment is specifically a drying box.

After the coprecipitate is obtained, in the present invention, the coprecipitate is calcined to obtain the catalyst for hydrogen production by methanol steam reforming.

In the present invention, the calcination temperature is preferably 250-350°C, more preferably 300°C; the time is preferably 1-12h, more preferably 2-8h, more preferably 3-6h. In the present invention, the calcining atmosphere is preferably air. The present invention does not have special requirements on the equipment used for the calcination, and the equipment well known to those skilled in the art can be used. In the embodiment of the present invention, the calcination equipment is specifically a muffle furnace.

In the present invention, calcination can fully remove water and organic matter in the coprecipitate, so that the metal salt precursor can be decomposed to obtain metal oxide, and the interaction between active metal, fullerene and oxide carrier can be further enhanced.

The present invention also provides another method for preparing a catalyst for hydrogen production by methanol steam reforming, comprising the following steps:

The soluble copper salt, oxide carrier, fullerene C ₆₀ and water are mixed for a second time to obtain a second mixed solution;

adding the precipitant aqueous solution to the second mixed solution, and performing aging to obtain a deposition precipitate;

The deposited precipitate is calcined to obtain the catalyst for hydrogen production by methanol steam reforming.

In the present invention, the soluble copper salt, the oxide carrier, the fullerene C ₆₀ and water are mixed for a second time to obtain a second mixed solution.

In the present invention, the type of the soluble copper salt is preferably the same as the above-mentioned technical solution, which is not repeated here.

In the present invention, the oxide carrier includes one or more of zinc oxide, aluminum oxide, zirconium oxide, cerium oxide and silicon dioxide, more preferably zinc oxide, aluminum oxide, zirconium oxide, ceria and silicon dioxide One or both of the silicon oxides. In the present invention, the particle size of the oxide carrier is preferably 5-200 nm, more preferably 5-50 nm; the specific surface area is preferably 20-800 m ² /g, more preferably 100-800 m ² /g.

In the present invention, the purity and source of the fullerene C ₆₀ are preferably consistent with the above technical solutions, which will not be repeated here.

In the present invention, the sequence of the second mixing preferably includes:

Mixing the water-soluble copper salt and water to obtain a water-soluble copper salt solution;

The fullerene C ₆₀ water is ultrasonically stirred and mixed to obtain a C ₆₀ dispersed solution;

ultrasonically stirring and mixing the oxide carrier and water to obtain a dispersion solution of the oxide carrier;

The water-soluble copper salt solution, the C ₆₀ dispersion solution and the dispersion solution of the oxide carrier are ultrasonically stirred and mixed to obtain a second mixed solution.

In the present invention, the concentration of the water-soluble copper salt solution is preferably 0.05 to 0.6 mol/L, more preferably 0.1 to 0.3 mol/L.

In the present invention, the concentration of the C ₆₀ dispersion solution is preferably consistent with the above-mentioned technical solution, which is not repeated here.

In the present invention, the concentration of the dispersion solution of the oxide carrier is preferably 10 to 50 mg/mL.

In the present invention, the volume ratio of the water-soluble copper salt solution, the C ₆₀ dispersion solution and the dispersion solution of the oxide carrier is preferably 2:1:2.

In the present invention, the operation of the ultrasonic stirring is consistent with the above technical solution, and details are not repeated here.

After the second mixed solution is obtained, the present invention adds the precipitant aqueous solution to the second mixed solution, and performs aging to obtain a deposited precipitate.

In the present invention, the type and concentration of the aqueous solution of the precipitating agent are preferably consistent with the above technical solutions, which will not be repeated here.

In the present invention, the addition rate of the precipitant aqueous solution is preferably 3-12 mL/min, more preferably 6-8 mL/min.

In the present invention, the aging operation is consistent with the above technical solution, and details are not repeated here.

After the deposited precipitate is obtained, the present invention calcines the deposited precipitate to obtain the catalyst for hydrogen production by methanol steam reforming.

In the present invention, the calcining operation is consistent with the above technical solution, and will not be repeated here.

The present invention also provides the catalyst for hydrogen production by methanol steam reforming described in the above technical solution or the catalyst for hydrogen production by methanol steam reforming obtained by the preparation method described in the above technical solution in the catalytic reaction of methanol steam reforming for hydrogen production applications in .

The present invention also provides a methanol steam reforming hydrogen production reaction, comprising the following steps:

reducing the catalyst for hydrogen production by methanol steam reforming described in the above technical solution or the catalyst for hydrogen production by methanol steam reforming obtained by the preparation method described in the above technical solution, to obtain a reduced catalyst;

Under the condition of a reduced catalyst, methanol and water undergo a hydrogen production reaction to obtain hydrogen.

In the present invention, the catalyst for hydrogen production by methanol steam reforming described in the above technical solution or the catalyst for hydrogen production by methanol steam reforming obtained by the preparation method described in the above technical solution is reduced to obtain a reduced catalyst.

In the present invention, the particle size of the catalyst for hydrogen production by methanol steam reforming is preferably 20-40 meshes.

In the present invention, the reduction temperature is 250-350°C, preferably 300°C; the time is 1-12h, preferably 2-8h, more preferably 3-6h. In the present invention, the reducing atmosphere is hydrogen; the flow rate of the hydrogen is preferably 10-200 mL/min, more preferably 30-100 mL/min, and more preferably 40-50 mL/min. In the present invention, the reducing instrument is preferably a tube furnace, and the present invention has no special requirements on the equipment used in the tube furnace, and the equipment well known to those skilled in the art may be used.

In the present invention, the reduction can fully activate the catalyst, and reduce the copper oxide particles to one valence or zero valence, so that the reduced catalyst has a higher catalytic reaction activity.

After the reduced catalyst is obtained, in the present invention, under the condition of the reduced catalyst, methanol and water are subjected to hydrogen production reaction to obtain hydrogen.

In the present invention, the conditions for the hydrogen production reaction preferably include: the temperature is 220-260°C, more preferably 230-250°C; the pressure is 0.1-1.0MPa, more preferably 0.1-0.3MPa, more preferably 0.1MPa The molar ratio of water and methanol is 0.9-1.5:1, more preferably 1.0-1.3:1, more preferably 1.2:1; the mass space velocity of methanol is 3-6h ^-1 , more preferably 4.5h ^-1 .

In the present invention, the hydrogen production reaction is preferably carried out in a fixed-bed reactor. When the hydrogen production reaction is preferably carried out in a fixed-bed reactor, the hydrogen production process is preferably: passing the mixed solution of methanol and water through the feed The sample pump is fed into the catalytic reaction tube; the loading amount of the reduced catalyst is preferably 0.5-5 g, more preferably 1-3 g.

In the present invention, the reaction tail gas is analyzed by online chromatography, and the analysis conditions preferably include: the chromatographic column is TDX-01, the column temperature is 100°C, the carrier gas is argon, the flow rate is 30mL/min, and the current is 80mA. According to the ratio of each component in the reaction tail gas, the conversion rate of methanol and the selectivity of various products were calculated.

The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

4.56 g of copper nitrate trihydrate, 3.83 g of zinc nitrate hexahydrate and 3.31 g of aluminum nitrate nonahydrate were dissolved in 100 mL of deionized water to obtain a salt solution. 0.3 g of fullerene C ₆₀ was ultrasonically stirred in 25 mL of deionized water to obtain a C ₆₀ dispersion solution. The above two solutions are then mixed and ultrasonically stirred to obtain a first mixed solution. The above-mentioned ultrasonic power was 40W, the stirring speed was 600r/min, and the ultrasonic stirring time was 30min. After configuring 125mL of 0.45mol/L sodium carbonate solution, the sodium carbonate solution (6mL/min) and the first mixed solution (6mL/min) were added to the reactor in co-current flow, stirring and aging at 600r/min under the heating condition of 60°C After 4h, the aging system was filtered at room temperature, and the solid obtained by filtration was washed, firstly washed twice with deionized water, then once with absolute ethanol, washed to neutrality, and dried at 100°C for 12h. A coprecipitate was obtained. Then, the coprecipitate was calcined in air at 300°C for 4 hours to obtain a catalyst for hydrogen production by methanol steam reforming, which was denoted as C ₆₀ -CuO/ZnO/Al ₂ O ₃ , wherein the theoretical mass percentage of copper oxide was is 45%; the theoretical mass percentage of fullerene C ₆₀ is 9.1%, and the balance is oxide carrier.

Example 2

4.56 g of copper nitrate trihydrate, 3.66 g of zirconium nitrate pentahydrate and 3.31 g of aluminum nitrate nonahydrate were dissolved in 100 mL of deionized water to obtain a salt solution. 0.3 g of fullerene C ₆₀ was ultrasonically stirred in 25 mL of deionized water to obtain a C ₆₀ dispersion solution. The above two solutions are then mixed and ultrasonically stirred to obtain a first mixed solution. The above-mentioned ultrasonic power was 40W, the stirring speed was 600r/min, and the ultrasonic stirring time was 30min. After configuring 125mL of 0.45mol/L sodium carbonate solution, the sodium carbonate solution (6mL/min) and the first mixed solution (6mL/min) were added to the reactor in co-current flow, stirring and aging at 600r/min under the heating condition of 60°C After 4h, the aging system was filtered at room temperature, and the solid obtained by filtration was washed, firstly washed twice with deionized water, then once with absolute ethanol, washed to neutrality, and dried at 100°C for 12h. A coprecipitate was obtained. Then the coprecipitate was calcined in air at 300°C for 4 hours to obtain a catalyst for hydrogen production by methanol steam reforming, which was denoted as C ₆₀ -CuO/ZrO ₂ /Al ₂ O ₃ , wherein the theoretical mass percentage of copper oxide was The content is 45%; the theoretical mass percentage of fullerene C ₆₀ is 9.1%, and the balance is oxide carrier.

Example 3

4.56 g of copper nitrate trihydrate, 3.66 g of zirconium nitrate pentahydrate and 0.85 g of cerium nitrate hexahydrate were dissolved in 100 mL of deionized water to obtain a salt solution. 0.3 g of fullerene C ₆₀ was ultrasonically stirred in 25 mL of deionized water to obtain a C ₆₀ dispersion solution. The above two solutions are then mixed and ultrasonically stirred to obtain a first mixed solution. The above-mentioned ultrasonic power was 40W, the stirring speed was 600r/min, and the ultrasonic stirring time was 30min. After configuring 125mL of 0.45mol/L sodium carbonate solution, the sodium carbonate solution (6mL/min) and the first mixed solution (6mL/min) were added to the reactor in co-current flow, stirring and aging at 600r/min under the heating condition of 60°C After 4h, the aging system was filtered at room temperature, and the solid obtained by filtration was washed, firstly washed twice with deionized water, then once with absolute ethanol, washed to neutrality, and dried at 100°C for 12h. A coprecipitate was obtained. Then, the coprecipitate was calcined in air at 300 °C for 4 h to obtain a catalyst for hydrogen production by methanol steam reforming, which was denoted as C ₆₀ -CuO/ZrO ₂ /CeO ₂ , wherein the theoretical mass percentage of copper oxide was 45%; the theoretical mass percentage of fullerene C ₆₀ is 9.1%, and the balance is oxide carrier.

Example 4

4.56 g of copper nitrate trihydrate was dissolved in 50 mL of deionized water to obtain a copper nitrate solution. 0.3 g of fullerene C ₆₀ was ultrasonically stirred in 25 mL of deionized water to obtain a C ₆₀ dispersion solution. Disperse 1.5 g of silica carrier in 50 mL of deionized water with ultrasonic stirring to obtain a silica carrier dispersion solution. The above three solutions are then mixed and ultrasonically stirred to obtain a second mixed solution. The above-mentioned ultrasonic power was 40W, the stirring speed was 600r/min, and the ultrasonic stirring time was 30min. After configuring 125mL of 0.3mol/L sodium carbonate solution, add the sodium carbonate solution to the second mixed solution at a dropping rate of 6mL/min, stir at 600r/min under 60℃ heating and age for 4h, then put the aging system at room temperature After filtration, the solid obtained by filtration was washed, firstly washed twice with deionized water, and then once with absolute ethanol. After washing to neutrality, it was dried at 100 °C for 12 h to deposit the precipitate; Air calcined at 300°C for 4 hours to obtain a catalyst for hydrogen production by methanol steam reforming, denoted as C ₆₀ -CuO/SiO ₂ , wherein the theoretical mass percentage of copper oxide is 45% _; The theoretical mass percentage is 9.1%, and the balance is oxide carrier.

Comparative Example 1

4.56 g of copper nitrate trihydrate, 4.6 g of zinc nitrate hexahydrate and 3.97 g of aluminum nitrate nonahydrate were dissolved in 100 mL of deionized water to obtain a salt solution. After configuring 125mL of 0.45mol/L sodium carbonate solution, add sodium carbonate solution (6mL/min) and salt solution (6mL/min) to the reactor in parallel, stir at 600r/min under 60℃ heating and age for 4h , filter the aging system at room temperature, wash the solid obtained by filtration, first wash twice with deionized water, then once with absolute ethanol, after washing to neutrality, dry at 100 ° C for 12 h to obtain a total of Then, the coprecipitate was calcined in air at 300 °C for 4 h to obtain a catalyst for hydrogen production by methanol steam reforming, which was recorded as CuO/ZnO/Al ₂ O ₃ , wherein the theoretical mass percentage of copper oxide was The content is 45%, and the balance is oxide carrier.

Comparative Example 2

4.56 g of copper nitrate trihydrate was dissolved in 50 mL of deionized water to obtain a copper nitrate solution. Disperse 1.5 g of silica carrier in 50 mL of deionized water with ultrasonic stirring to obtain a silica carrier dispersion solution. The above two solutions are then mixed and ultrasonically stirred to obtain a second mixed solution. The above-mentioned ultrasonic power was 40W, the stirring speed was 600r/min, and the ultrasonic stirring time was 30min. After configuring 125mL of 0.3mol/L sodium carbonate solution, add the sodium carbonate solution to the above second mixed solution at a dropping rate of 6mL/min, stir at 600r/min at 60°C and age for 4h, then put the aging system in Filter at room temperature, wash the solid obtained by filtration, first wash twice with deionized water, then once with absolute ethanol, after washing to neutrality, dry at 100 ° C for 12 hours to obtain the sediment; then, The deposited precipitate was calcined in air at 300 °C for 4 h to obtain a catalyst for hydrogen production by methanol steam reforming, which was recorded as CuO/SiO ₂ , wherein the theoretical mass percentage of copper oxide was 45%, and the balance was oxidation material carrier.

Application examples 1 to 6

The catalysts for hydrogen production by methanol steam reforming prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were pressed into tablets and then screened to obtain catalyst particles of 20 to 40 meshes; the catalyst particles were further placed in a 50 mL/min hydrogen stream. , under the condition of 300 ℃ for 4h reduction treatment to obtain the reduced catalyst.

The reduced catalysts prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were placed in a fixed-bed continuous reactor with methanol-water mixed raw materials, respectively, and the reaction was carried out. The loading of the methanol-steam reforming catalyst for hydrogen production was 1.5 g , the temperature is 240°C, the pressure is 0.1MPa, the molar ratio of water and methanol is 1.2:1, and the mass space velocity of methanol is 4.5h ^-1 .

The components of the reaction products obtained in application examples 1 to 6 were measured, and the results obtained are shown in Table 1; among which: the conversion rate of methanol (MeOH), the selectivity distribution of product carbon dioxide (CO ₂ ), carbon monoxide (CO) and hydrogen production rate.

Table 1 Catalytic performance of catalysts obtained in Examples 1-4 and Comparative Examples 1-2 for methanol steam reforming for hydrogen production

As can be seen from Table 1: the catalyst for hydrogen production by methanol reforming prepared by the present invention adopts fullerene C ₆₀ to promote copper for activating methanol and water vapor, can efficiently produce hydrogen at lower temperature and inhibit the by-product CO formed, showing excellent catalytic effect. Among them, the Cu/ZnO/Al ₂ O ₃ promoted by the fullerene C ₆₀ obtained in Example 1 achieved the highest hydrogen production rate, which was higher than that of the Cu/ZnO/Al ₂ O ₃ catalyst without fullerene addition. a 40% boost. In Examples 2 and 3, by adjusting the composition of the catalyst oxide carrier, a very good effect of low temperature methanol steam reforming for hydrogen production was also obtained. In addition, although the hydrogen production rate of the Cu/SiO ₂ series catalyst in Comparative Example 2 is low, there is no by-product CO generated. By introducing fullerene C ₆₀ , it is found that C ₆₀ -Cu/SiO ₂ in Example 4 achieves nearly double the hydrogen production rate improvement effect, and there is still no CO generation.

The catalyst for hydrogen production by methanol steam reforming prepared in Example 1 was pressed into tablets and then screened to obtain catalyst particles of 20 to 40 meshes; the catalyst particles were further subjected to reduction treatment at 300°C in a 50mL/min hydrogen stream. 4h, the reduced catalyst was obtained; the catalyst life was tested on the fixed bed reaction system. During the test, the pressure of the reforming hydrogen production reaction was controlled to be 0.1 MPa, the temperature was 240 °C, and the molar ratio of raw water to methanol was 1.2:1. The mass space velocity of methanol was 4.5h- ¹ , and samples were taken online every 4h to analyze the reaction results. The obtained results are shown in Figure 1. It can be seen from Figure 1 that the conversion rate of methanol, the selectivity of CO and the hydrogen production rate of the raw material remain stable, and after the continuous reaction for 200h, there is no deactivation phenomenon, indicating that the methanol steam reforming prepared in Example 1 produces hydrogen The structure and performance of the catalyst are very stable.

The catalysts for hydrogen production by methanol steam reforming obtained in Example 1 and Comparative Example 1 were tested by X-ray powder diffraction, and the obtained results are shown in FIG. 2 . It can be seen that the fullerene C ₆₀ is well dispersed in the catalyst, and the introduction does not have a great influence on the catalyst structure.

The catalyst for hydrogen production by steam reforming of methanol obtained in Example 1 was characterized by transmission electron microscopy, and the obtained results are shown in FIG. 3 . The left picture in Fig. 3 is the TEM photo after magnification of 10 ⁵ times, and the right picture is the TEM photo after magnification of 10 ⁶ times. It can be seen from Figure 3 that the size of the zinc oxide and aluminum oxide supports is between 5 and 30 nm, the size of copper oxide is between 2 and 15 nm, and the relative molecular weight of fullerene C ₆₀ is lighter and better dispersed. No apparent agglomeration was found.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. A catalyst for hydrogen production by methanol steam reforming is characterized by comprising an oxide carrier and an active component loaded on the oxide carrier; the active ingredients comprise copper oxide and fullerene C₆₀(ii) a The oxide carrier comprises one or more of zinc oxide, aluminum oxide, zirconium oxide, cerium oxide and silicon dioxide;

the preparation method of the catalyst for hydrogen production by methanol steam reforming comprises the following steps:

dissolving soluble copper salt, water-soluble salt corresponding to oxide carrier, and fullerene C₆₀Carrying out first mixing with water to obtain a first mixed solution;

the first mixed solution and the precipitant aqueous solution are mixed in a parallel flow mode and aged to obtain a coprecipitate;

calcining the coprecipitate to obtain the catalyst for hydrogen production by methanol steam reforming;

in the catalyst for hydrogen production by methanol steam reforming, the mass percentage of the copper oxide is 10-60%.

2. The catalyst for hydrogen production by methanol steam reforming as claimed in claim 1, wherein the catalyst for hydrogen production by methanol steam reforming contains 1 to 30% by mass of fullerene C60, and the balance is an oxide carrier.

3. The method for producing a catalyst for hydrogen production by methanol steam reforming according to claim 1 or 2, comprising the steps of:

carrying out first mixing on a soluble copper salt, a water-soluble salt corresponding to an oxide carrier, fullerene C60 and water to obtain a first mixed solution;

the first mixed solution and the precipitant aqueous solution are mixed in a parallel flow mode and aged to obtain a coprecipitate;

and calcining the coprecipitate to obtain the catalyst for hydrogen production by methanol steam reforming.

4. The method for producing a catalyst for hydrogen production by methanol steam reforming according to claim 1 or 2, comprising the steps of:

carrying out second mixing on soluble copper salt, an oxide carrier, fullerene C60 and water to obtain a second mixed solution;

adding a precipitant aqueous solution into the second mixed solution, and aging to obtain a precipitate;

and calcining the deposition precipitate to obtain the catalyst for hydrogen production by methanol steam reforming.

5. The production method according to claim 3 or 4, wherein the aqueous precipitant solution is an aqueous ammonia solution or an aqueous alkali solution; the mass concentration of the ammonia water is 26-28%; the alkaline matter in the alkaline water solution is urea, sodium carbonate, potassium carbonate, sodium hydroxide or potassium hydroxide.

6. The preparation method according to claim 3 or 4, wherein the aging temperature is 30-120 ℃ and the aging time is 6-24 h; the aging is carried out under the condition of stirring, and the rotating speed of the stirring is 200-900 r/min.

7. The preparation method according to claim 3 or 4, wherein the calcining temperature is 250-350 ℃ and the calcining time is 1-12 h; the atmosphere of the calcination is air.

8. Use of the catalyst for hydrogen production by methanol steam reforming according to claim 1 or 2 or the catalyst for hydrogen production by methanol steam reforming obtained by the production method according to any one of claims 3 to 7 in catalyzing a reaction for hydrogen production by methanol steam reforming.

9. A methanol steam reforming hydrogen production reaction comprises the following steps:

reducing the catalyst for hydrogen production by methanol steam reforming according to claim 1 or 2 or the catalyst for hydrogen production by methanol steam reforming obtained by the production method according to any one of claims 3 to 7 to obtain a reduced catalyst;

under the condition of a reduction catalyst, methanol and water carry out hydrogen production reaction to obtain hydrogen;

the reducing atmosphere is hydrogen, the temperature is 250-350 ℃, and the time is 1-12 h.

10. The methanol steam reforming hydrogen production reaction of claim 9, wherein the hydrogen production reaction conditions include: the temperature is 220-260 ℃, the pressure is 0.1-1.0 MPa, the molar ratio of water to methanol is 0.9-1.5: 1, and the mass space velocity of methanol is 3-6 h^-1。

Images