CN111589464B - Boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst and preparation method and application thereof - Google Patents

Abstract

The invention provides a boron nitride loaded rhodium-gallium-tin liquid alloy catalyst, and a preparation method and application thereof, and belongs to the technical field of catalysts. The boron nitride loaded rhodium-gallium-tin liquid alloy catalyst provided by the invention comprises boron nitride and an active component loaded on the surface of the boron nitride; the active component includes a rhodium gallium tin liquid alloy. The invention takes rhodium, gallium and tin as active components, takes boron nitride as a carrier, and forms a liquid stable structure of three metals among rhodium atoms, gallium atoms and tin atoms, so that the rhodium, the gallium and the tin cannot be agglomerated and have good dispersibility; the bonding force of rhodium, gallium and tin with the boron nitride carrier is strong, and the stability of the catalyst is high; and compared with the catalyst loaded with noble metals (Pd, ag and Au), the cost of the catalyst is greatly reduced.

Description

A kind of boron nitride supported rhodium-gallium-tin liquid alloy catalyst and its preparation method and application

technical field

The invention relates to the technical field of catalysts, in particular to a boron nitride-supported rhodium-gallium-tin liquid alloy catalyst and a preparation method and application thereof.

Background technique

Petroleum cracking is a method commonly used in industry to prepare ethylene, but the obtained ethylene usually contains trace amounts of acetylene. The content of acetylene seriously affects the ethylene polymerization reaction, and the quality of polyethylene is significantly reduced. Therefore, it is urgent to remove acetylene in the industry to reduce its content to below 5ppm. This is a research hotspot in recent years.

At present, the commonly used methods for removing trace amounts of acetylene in ethylene are partial oxidation steam reforming and catalytic hydrogenation. Among them, the catalytic hydrogenation reaction is the main method for industrially removing trace amounts of acetylene due to its mild reaction conditions, low energy consumption and convenient operation. The choice of catalyst in the process of hydrogenation reaction is an important factor affecting the reaction result.

Because Pd has good adsorption to acetylene and can activate it to promote the conversion of acetylene, supported Pd catalysts are widely used in industry. However, Pd metal is expensive, and its activity and reaction selectivity to acetylene are still insufficient. In order to improve the catalytic performance of Pd catalysts, Pd is often mixed with other metals such as Ag or Au, or Pd is loaded on silica or alumina. etc. on the carrier. However, the catalytic activity of the above-mentioned supported Pd catalysts is low.

Contents of the invention

The object of the present invention is to provide a boron nitride-supported rhodium-gallium-tin liquid alloy catalyst and its preparation method and application. The boron nitride-supported rhodium-gallium-tin liquid alloy catalyst provided by the present invention has high catalytic activity and low cost.

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

The invention provides a boron nitride supported rhodium-gallium-tin liquid alloy catalyst, which comprises boron nitride and an active component supported on the surface of the boron nitride; the active component comprises a rhodium-gallium-tin liquid alloy.

Preferably, the content of active components in the boron nitride-supported rhodium-gallium-tin liquid alloy catalyst is 0.8-8.5wt%.

The present invention provides the preparation method of the boron nitride supported rhodium-gallium-tin liquid alloy catalyst described in the above technical scheme, comprising the following steps:

mixing a water-soluble rhodium source, a water-soluble gallium source, a water-soluble tin source and water, mixing the resulting mixed solution with boron nitride, standing and impregnating, and then drying to obtain a catalyst precursor;

The catalyst precursor is sequentially calcined and reduced to obtain a boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst.

Preferably, the quality of the water-soluble rhodium source, water-soluble gallium source and water-soluble tin source is based on the mass of rhodium, gallium and tin respectively, and the water-soluble rhodium source, water-soluble gallium source, water-soluble tin source and nitrogen The mass ratio of boron chloride is 0.002-0.015:0.003-0.04:0.003-0.04:1.

Preferably, the water-soluble rhodium source includes rhodium chloride, rhodium nitrate, ammonium chlororhodate, rhodium sulfate, potassium hexachlororhodate (III) or rhodium (III) triacetylacetonate.

Preferably, the water-soluble gallium source includes gallium nitrate, gallium chloride, gallium ethoxide, gallium isopropoxide, gallium acetylacetonate or gallium triethylate.

Preferably, the water-soluble tin source includes stannous chloride dihydrate, tin tetrachloride, sodium stannate, tetraphenyltin, tin acetylacetonate chloride, stannous sulfate or tin ethoxide.

Preferably, the temperature of the calcination is 500-1000° C., and the time is 2-6 hours.

Preferably, the reducing gas used in the reduction reaction includes one or more of hydrogen, methane, hydrogen sulfide and ammonia;

The temperature of the reduction reaction is 200-600° C., and the time is 1-5 hours.

The present invention also provides the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst described in the above technical scheme or the present invention provides the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst prepared by the preparation method described in the above technical scheme. applications in acetylene.

The invention provides a boron nitride supported rhodium-gallium-tin liquid alloy catalyst, which comprises boron nitride and an active component supported on the surface of the boron nitride; the active component comprises a rhodium-gallium-tin liquid alloy. The present invention uses rhodium, gallium and tin as active components, forming strong metal bonds between rhodium atoms, gallium atoms and tin atoms, high stability, strong binding force with boron nitride carrier, and making rhodium, gallium and tin Tin will not be agglomerated, and can obtain a uniform active center, which can improve the catalytic activity of the catalyst; and the cost is greatly reduced compared with the cost of noble metals (Pd, Ag, Au). The invention uses boron nitride as a carrier, can improve the dispersion of rhodium, gallium and tin in the catalyst and the binding force with rhodium, gallium and tin, and is beneficial to increase the catalytic activity and stability of the catalyst. The boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst provided by the invention forms a self-protecting oxide layer liquid film in the process of catalytic hydrogenation to remove acetylene in ethylene, which can avoid secondary reactions of ethylene on the surface of the catalyst, thereby inhibiting the deep acceleration of acetylene. Hydrogen forms ethane by-product, which is highly catalytic for acetylene.

The invention provides a preparation method of the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst, which has simple operation, low raw material cost, no secondary pollution and is suitable for industrialized production.

Description of drawings

Fig. 1 is the TEM figure of the boron nitride loaded rhodium-gallium-tin liquid alloy catalyst prepared by embodiment 1;

Fig. 2 is the catalytic effect diagram of the boron nitride supported rhodium-gallium-tin liquid alloy catalyst prepared by embodiment 1 to the hydrogenation of acetylene;

Fig. 3 is the catalytic effect figure of the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst prepared by embodiment 2 to the hydrogenation of acetylene;

Fig. 4 is the catalytic effect diagram of the boron nitride supported rhodium-gallium-tin liquid alloy catalyst prepared by embodiment 3 to the hydrogenation of acetylene;

Fig. 5 is the catalytic effect diagram of the boron nitride supported rhodium-gallium-tin liquid alloy catalyst prepared by embodiment 4 to the hydrogenation of acetylene;

Fig. 6 is the catalytic effect diagram of the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst prepared in embodiment 5 to the hydrogenation of acetylene;

Fig. 7 is the catalytic effect diagram of the boron nitride supported rhodium gallium tin liquid alloy catalyst prepared by comparative example 1 to the hydrogenation of acetylene;

Fig. 8 is a diagram showing the catalytic effect of the boron nitride-supported rhodium-gallium-tin liquid alloy catalyst prepared in Comparative Example 2 on the hydrogenation of acetylene.

Detailed ways

The invention provides a boron nitride supported rhodium-gallium-tin liquid alloy catalyst, which comprises boron nitride and an active component supported on the surface of the boron nitride; the active component comprises a rhodium-gallium-tin liquid alloy.

In the present invention, the content of active components in the boron nitride-supported rhodium-gallium-tin liquid alloy catalyst is preferably 0.8-8.5 wt%, more preferably 1-8 wt%, most preferably 2-7 wt%. In the present invention, in the boron nitride-supported rhodium-gallium-tin liquid alloy catalyst, the content of rhodium is preferably 0.2-1.5 wt%, more preferably 0.3-1.2 wt%, most preferably 0.5-1 wt%; the content of gallium Preferably 0.3-4wt%, more preferably 1-3wt%, most preferably 1.5-2.5wt%; tin content is preferably 0.3-4wt%, more preferably 1-3wt%, most preferably 1.5-2.5wt% . In the present invention, the rhodium atom in the rhodium element in the rhodium gallium tin liquid alloy, the gallium atom in the gallium element and the tin atom in the tin element form a stable structure of a three-metal liquid alloy, so that rhodium, gallium and Tin will not be agglomerated, has a strong binding effect with the boron nitride carrier, and can obtain a uniform active center, which can improve the catalytic activity of the catalyst; and the cost is greatly reduced compared with the cost of noble metals (Pd, Ag, Au).

The present invention provides the preparation method of the boron nitride supported rhodium-gallium-tin liquid alloy catalyst described in the above technical scheme, comprising the following steps:

Mixing a water-soluble rhodium source, a water-soluble gallium source, a water-soluble tin source and water, mixing the obtained mixed solution with boron nitride, performing static impregnation and drying to obtain a catalyst precursor;

The catalyst precursor is sequentially calcined and reduced to obtain a boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst.

In the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art.

The invention mixes a water-soluble rhodium source, a water-soluble gallium source, a water-soluble tin source and water, mixes the obtained mixed solution with boron nitride, performs static impregnation and then dries to obtain a catalyst precursor.

In the present invention, the water-soluble rhodium source preferably includes rhodium chloride, rhodium nitrate, ammonium chlororhodate, rhodium sulfate, potassium hexachlororhodium(III) or rhodium(III) triacetylacetonate, more preferably rhodium chloride rhodium. In the present invention, the water-soluble gallium source preferably includes gallium nitrate, gallium chloride, gallium ethoxide, gallium isopropoxide, gallium acetylacetonate or gallium triethylate, more preferably gallium chloride. In the present invention, the water-soluble tin source preferably includes stannous chloride dihydrate, tin tetrachloride, sodium stannate, tetraphenyl tin, acetylacetonate tin chloride, stannous sulfate or tin ethoxide, more preferably For stannous chloride dihydrate.

In the present invention, the quality of the water-soluble rhodium source, the water-soluble gallium source and the water-soluble tin source is based on the mass of rhodium, gallium and tin respectively, the water-soluble rhodium source, the water-soluble gallium source, the water-soluble tin source The mass ratio to boron nitride is preferably 0.002-0.015:0.003-0.04:0.003-0.04:1, more preferably 0.003-0.012:0.01-0.03:0.01-0.03:1, most preferably 0.005-0.01:0.015-0.025 :0.015～0.025:1.

In the present invention, mixing the water-soluble rhodium source, water-soluble gallium source, water-soluble tin source and water preferably includes mixing the water-soluble rhodium source and the first part of water first to obtain a rhodium source solution; mixing the water-soluble gallium source and The second part of water is mixed for the second time to obtain gallium source solution; the third part of water-soluble tin source is mixed with the third part of water to obtain tin source solution; the rhodium source solution, gallium source solution, tin source solution and remaining water are mixed for the fourth Mix to obtain a mixed solution. The present invention has no special limitation on the consumption of the first part of water, the second part of water and the third part of water, and it can ensure that the concentrations of the rhodium source solution, gallium source solution and tin source solution are independently 5 to 15 mg/mL, i.e. Yes, more preferably 8-12 mg/mL, more preferably 10 mg/mL. In the present invention, there is no special limitation on the amount of the remaining water, as long as the mass-to-volume ratio of boron nitride to the mixed solution is 1 g:20 mL. In the present invention, the methods of the first mixing, the second mixing, the third mixing and the fourth mixing are all preferably stirring and mixing, and the present invention has no special limitation on the speed of the stirring and mixing, as long as the raw materials can be mixed evenly . In the present invention, there is no special limitation on the time of the first mixing, the second mixing and the third mixing, as long as the water-soluble rhodium source, water-soluble gallium source or water-soluble tin source can be dissolved in water. In the present invention, the fourth mixing time is preferably 0.5-1 h.

In the present invention, when gallium chloride (GaCl ₃ ) is used as the water-soluble gallium source, the GaCl ₃ is preferably dissolved in a strong acid, and then mixed with the second part of water to obtain a chloropalladium acid solution; the strong acid Preferably include hydrochloric acid, nitric acid or sulfuric acid; the concentration of the strong acid is preferably 10-12mol/L, more preferably 12mol/L; the mass-volume ratio of the palladium chloride to the strong acid is preferably 1g:1-3mL, more preferably 1g : 3mL. In the present invention, GaCl ₃ is firstly dissolved in concentrated hydrochloric acid, so that trivalent gallium ions can exist in the form of Ga ^{3 +} .

In the present invention, when stannous chloride dihydrate is used as the water-soluble tin source, it is preferred to dissolve the stannous chloride dihydrate in a strong acid, and then mix it with a third part of water to obtain An acid solution of tin; the strong acid preferably includes hydrochloric acid, nitric acid or sulfuric acid; the concentration of the strong acid is 10 to 12mol/L, more preferably 12mol/L; the mass volume ratio of the stannous chloride to the strong acid is preferably 1g : 1-3mL, more preferably 1g: 3mL, which can avoid the decomposition of stannous chloride dihydrate in neutral aqueous solution to form precipitates.

In the present invention, the mixing method of the mixed solution and boron nitride is preferably stirring and mixing, and the speed of the stirring and mixing is not particularly limited in the present invention, as long as the raw materials can be mixed evenly. In the present invention, the mixing time is preferably 0.5-1 h.

In the present invention, the static impregnation is preferably carried out under static conditions, and the static time is preferably 6-12 hours, more preferably 8-10 hours. In the present invention, during the static impregnation process, the water-soluble rhodium source, the water-soluble gallium source and the water-soluble tin source are loaded on the surface of boron nitride.

In the present invention, the drying is preferably vacuum drying, and the vacuum drying temperature is preferably 70-100°C, more preferably 80°C; the vacuum drying time is preferably 6-15h, more preferably 8-12h .

After the catalyst precursor is obtained, in the present invention, the catalyst precursor is sequentially calcined and reduced to obtain a boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst.

In the present invention, the calcination temperature is preferably 500-1000° C., more preferably 600-800° C.; the calcination time is preferably 2-6 hours, more preferably 3-5 hours. In the present invention, the calcination is preferably carried out in a protective atmosphere, and the protective atmosphere is preferably nitrogen or argon. In the present invention, during the calcination process, the water-soluble rhodium source, water-soluble gallium source and water-soluble tin source are thermally decomposed in situ on the surface of boron nitride to obtain rhodium oxide, gallium oxide and tin oxide respectively.

In the present invention, the reducing gas used in the reduction reaction preferably includes one or more of hydrogen, methane, hydrogen sulfide and ammonia, more preferably includes hydrogen, methane, hydrogen sulfide or ammonia, most preferably hydrogen . When the present invention utilizes two or more reducing gases, the present invention has no special limitation on the usage ratio of different reducing gases, and any ratio is acceptable. In the present invention, the flow rate ratio of the calcined product to the reducing gas is preferably 0.5g: 30-50mL/min, more preferably 0.5g: 40mL/min.

In the present invention, the temperature of the reduction reaction is preferably 200-600° C., more preferably 300-500° C.; the time of the reduction reaction is preferably 1-5 hours, more preferably 2-4 hours. In the present invention, during the reduction reaction, rhodium oxide, gallium oxide and tin oxide are respectively reduced to simple rhodium, gallium and tin, while the active components rhodium, gallium and tin interact to form three The liquid stable structure of the metal prevents rhodium, gallium and tin from agglomerating, and has a strong binding effect with the boron nitride carrier, which is beneficial to increase the catalytic activity and stability of the catalyst.

The preparation method provided by the invention has simple operation, low raw material cost, uses water as a solvent, has no secondary pollution, and is suitable for industrialized production.

The present invention also provides the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst described in the above technical scheme or the present invention provides the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst prepared by the preparation method described in the above technical scheme. applications in acetylene.

In the present invention, the boron nitride-supported rhodium-gallium-tin liquid alloy catalyst is preferably activated before application. In the present invention, the activation treatment preferably uses hydrogen to reduce and activate the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst; the ratio of the mass of the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst to the volume of hydrogen is preferably 1g: (200～6000)mL, more preferably 1g: (1000～3000)mL; the temperature of the activation treatment is preferably 100～300°C, preferably 150～250°C; the time of the activation treatment is preferably 0.5～2h , more preferably 1h.

In the present invention, the reaction conditions for the boron nitride-supported rhodium-gallium-tin liquid alloy catalyst for catalytic hydrogenation to remove acetylene in ethylene preferably include: the reaction gas is preferably a mixture of C ₂ H ₂ /H ₂ /C ₂ H ₄ Gas; the molar ratio of C ₂ H ₂ , H ₂ and C ₂ H ₄ in the reaction gas is preferably 1:2-10:60-100, more preferably 1:3-8:70-90, most preferably 1:4～6:70～80, the volume space velocity of the reaction gas is 1000～36000h ^-1 , more preferably 1100～10000h ^-1 , more preferably 1200～5000h ^-1 ; the boron nitride supports rhodium The ratio of gallium-tin liquid alloy catalyst quality and reaction gas pressure is preferably 0.2g: (0.05～0.2) MPa, more preferably 0.2g: (0.05～0.1) MPa; The temperature of reaction is preferably 30～210 ℃, more preferably 50-180°C, most preferably 80-120°C; the reaction time is preferably 30-60h, more preferably 40-50h.

In the present invention, the hydrogenation of acetylene to prepare ethylene is preferably carried out in a fixed bed reactor, more preferably a fixed bed microreactor; the inner diameter of the fixed bed cavity of the fixed bed microreactor is preferably 2 cm, which can be heated at a constant temperature The zone length is preferably 10 cm.

In an embodiment of the present invention, the catalytic effect of the boron nitride-supported rhodium-gallium-tin liquid alloy catalyst is preferably analyzed by a gas chromatograph with an FID detector, wherein the sampling interval is preferably 0.5h.

The boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst used in the present invention forms a self-protecting oxide layer liquid film in the process of catalyzing the hydrogenation of acetylene to prepare ethylene, which can avoid the secondary reaction of ethylene on the surface of the catalyst, thereby inhibiting the formation of deep hydrogenation of acetylene Ethane by-product, high selectivity to ethylene, high catalytic activity.

The technical solutions in the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

(1) Dissolve 1g of rhodium chloride in deionized water, transfer to a 100mL volumetric flask, add deionized water to the scale of the volumetric flask and shake up to obtain a rhodium chloride solution with a concentration of 10mg/mL;

Dissolve 1g of gallium chloride in 3mL of concentrated hydrochloric acid (12mol/L), transfer to a 100mL volumetric flask, add deionized water to the scale of the volumetric flask and shake well to obtain an acid solution of gallium chloride with a concentration of 10mg/mL ;

Dissolve 1g of stannous chloride dihydrate in 3mL of concentrated hydrochloric acid (12mol/L), transfer it to a 100mL volumetric flask, add deionized water to the scale of the volumetric flask, and shake well to obtain a chloride concentration of 10mg/mL. Acid solution of stannous;

Pipette 4.01mL of rhodium chloride solution, 2.52mL of gallium chloride solution and 1.46mL of stannous chloride solution with a 1mL pipette gun, add deionized water to a total volume of 20mL, stir and mix for 0.5h to obtain a mixed solution;

(2) Add the mixed solution into 1 g of boron nitride, stir and mix for 1 h, stand for impregnation for 6 h, then place in a vacuum drying oven and dry at 80° C. for 8 h to obtain a catalyst precursor.

(3) Calcining the catalyst precursor under argon protection at 500° C. for 4 hours, and then reducing it under hydrogen atmosphere at 200° C. for 2 hours to obtain a boron nitride-supported rhodium-gallium-tin liquid alloy catalyst.

The TEM figure of the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst prepared by the present embodiment is as shown in Figure 1, as can be seen from Figure 1, the rhodium-gallium-tin liquid alloy particles in the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst prepared by the present invention The uniform distribution shows that the boron nitride-supported rhodium-gallium-tin liquid alloy catalyst provided by the present invention has no metal agglomeration, and the catalyst has good dispersion.

Embodiment 2-5

The boron nitride-supported rhodium-gallium-tin liquid alloy catalyst was prepared according to the method of Example 1, and the preparation conditions of Examples 2-5 are shown in Table 1.

Comparative example 1～2

The catalyst was prepared according to the method of Example 1, and the preparation conditions of Comparative Examples 1-2 are shown in Table 1.

The consumption of each raw material in table 1 embodiment 1～5 and comparative example 1～2

Application example

The catalysts prepared in Examples 1-5 and Comparative Examples 1-2 are used as catalysts for hydrogenating acetylene to prepare ethylene, and are used for hydrogenating acetylene to prepare ethylene.

Among them, the reaction conditions for the hydrogenation of acetylene to prepare ethylene are as follows: 200 mg of catalyst is loaded on a fixed-bed microreactor, and the reaction gas is C ₂ H ₂ /H ₂ /C ₂ H ₄ mixed gas (C ₂ H ₂ , H ₂ and The molar ratio of C ₂ H ₄ =1:2:100), the volume space velocity of the reaction gas is 1200h ^-1 , the reaction pressure is 0.05MPa, the reaction temperature is 100°C, and the reaction time is 100h; the gas chromatography using the FID detector Instrument for analysis, the sampling interval is preferably 0.5h; the fixed bed chamber internal diameter of the fixed bed microreactor is preferably 2cm, and the length of the constant temperature heating zone is preferably 10cm.

The catalytic effects of the catalysts prepared in Examples 1 to 5 and Comparative Examples 1 to 2 in different reaction times are shown in Figures 2 to 8 and Table 2, wherein Figure 2 is Example 1, Figure 3 is Example 2, and Figure 4 It is embodiment 3, Fig. 5 is embodiment 4, Fig. 6 is embodiment 5, Fig. 7 is comparative example 1, Fig. 8 is comparative example 2.

The catalytic effect of the catalyst prepared by table 2 embodiment 1～5 and comparative example 1～2

Conversion rate of acetylene/% Ethylene selectivity/% Example 1 98.9 99.6 Example 2 97.4 94.3 Example 3 88.8 88.4 Example 4 95.4 92.2 Example 5 93.4 90.1 Comparative example 1 50.4 47.4 Comparative example 2 46.9 42.1

As can be seen from Figures 2 to 6, the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst prepared in Examples 1 to 5 of the present invention increases the conversion rate of acetylene in 0 to 5 hours as the prolongation of the reaction time increases, and in 5 to 90 hours, the conversion rate of acetylene increases. The conversion ratio of the catalyst is maintained at about 98.9%, 97.4%, 88.8%, 95.4%, 93.4% successively, and the activity of the catalyst begins to decline slightly after the reaction time exceeds 90h, indicating that the boron nitride supported rhodium-gallium-tin liquid alloy catalyst provided by the present invention long life. As can be seen from Table 2, the boron nitride supported rhodium-gallium-tin liquid alloy catalyst prepared in Examples 1 to 5 has a conversion rate of 88.8 to 98.9% to acetylene, and a selectivity to ethylene of 88.4 to 99.6%, showing that the catalyst provided by the present invention The conversion rate of acetylene is high, the selectivity to ethylene is high, and the catalytic effect is excellent.

From Figures 7 to 8, it can be seen that the conversion rate of acetylene in the catalysts prepared in Comparative Examples 1 to 2 increases with the prolongation of the reaction time within 0 to 5 hours, and the conversion rate of acetylene in 5 to 90 hours is maintained at about 50.4% and 46.9% in sequence. %, the activity of the catalyst began to decrease slightly after the reaction time exceeded 90 h. As can be seen from Table 2, the conversion of the catalysts prepared in Comparative Examples 1 to 2 to acetylene is only 46.9 to 50.4%, and the selectivity to ethylene is only 42.1 to 47.4%. The conversion rate of acetylene is low, the selectivity to ethylene is low, and the catalytic effect is poor.

By comparing the catalytic effects of the catalysts prepared in Example 1 and Comparative Examples 1 to 2, it can be seen that compared with the state alloy catalysts of two metals in rhodium, gallium, and tin loaded on the surface of boron nitride, the present invention passes through boron nitride The catalyst obtained by loading the three metals of rhodium, gallium and tin has excellent catalytic effect on catalytic hydrogenation to remove acetylene in ethylene.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. A boron nitride supported rhodium-gallium-tin liquid alloy catalyst comprises boron nitride and an active component supported on the surface of the boron nitride; the active component comprises a rhodium-gallium-tin liquid alloy; the boron nitride In the rhodium-gallium-tin liquid alloy catalyst, the gallium content is 0.3-2.5 wt%, and the tin content is 0.3-2.5 wt%. 2. The boron nitride-supported rhodium-gallium-tin liquid alloy catalyst according to claim 1, characterized in that, the content of active components in the boron nitride-supported rhodium-gallium-tin liquid alloy catalyst is 0.8-8.5wt%. 3. the preparation method of boron nitride supported rhodium-gallium-tin liquid alloy catalyst described in claim 1 or 2, is characterized in that, comprises the following steps: mixing a water-soluble rhodium source, a water-soluble gallium source, a water-soluble tin source and water, mixing the resulting mixed solution with boron nitride, standing and impregnating, and then drying to obtain a catalyst precursor; The catalyst precursor is sequentially calcined and reduced to obtain a boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst. 4. preparation method according to claim 3, is characterized in that, the quality of described water-soluble rhodium source, water-soluble gallium source and water-soluble tin source is in the mass meter of rhodium, gallium and tin respectively, and described water-soluble rhodium The mass ratio of the gallium source, the water-soluble gallium source, the water-soluble tin source and the boron nitride is 0.002-0.015:0.003-0.04:0.003-0.04:1. 5. according to the described preparation method of claim 3 or 4, it is characterized in that, described water-soluble rhodium source comprises rhodium chloride, rhodium nitrate, ammonium chlororhodate, rhodium sulfate, hexachlororhodium (III) potassium or three Rhodium(III) acetylacetonate. 6. The preparation method according to claim 3 or 4, wherein the water-soluble gallium source comprises gallium nitrate, gallium chloride, gallium ethoxide, gallium isopropoxide, gallium acetylacetonate or gallium triethylate. 7. according to the described preparation method of claim 3 or 4, it is characterized in that, described water-soluble tin source comprises tin protochloride dihydrate, tin tetrachloride, sodium stannate, tetraphenyltin, acetylacetonate chloride tin oxide, stannous sulfate, or tin ethoxide. 8 . The preparation method according to claim 3 , characterized in that, the temperature of the calcination is 500-1000° C. and the time is 2-6 hours. 9. The preparation method according to claim 3, wherein the reducing gas utilized in the reduction reaction comprises one or more of hydrogen, methane, hydrogen sulfide and ammonia; The temperature of the reduction reaction is 200-600° C., and the time is 1-5 hours. 10. The boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst described in any one of claims 1 to 2 or the boron nitride-loaded rhodium-gallium-tin liquid alloy catalyst prepared by the preparation method described in any one of claims 3 to 9 is catalytically added Application of hydrogen to remove acetylene from ethylene.

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