CN106955729A - Para-nitrotoluene hydrogenation ruthenium lanthanum bimetallic catalyst and preparation method thereof - Google Patents

Abstract

A ruthenium-lanthanum bimetallic catalyst for the hydrogenation of p-nitrotoluene and a preparation method thereof, the catalyst comprises an active component ruthenium, an auxiliary agent lanthanum and a carrier, and the catalyst composition is expressed as: x% Ru-y%La/carrier, where x% represents The mass percentage of Ru in the catalyst, y% represents the mass percentage of La in the catalyst, and the content of each component of the catalyst is Ru: 0.5%-5%, La: 0.2%-2%, and the rest are carriers. The catalyst precursor is prepared by an impregnation-precipitation method, and then the catalyst precursor is reduced in a hydrogen-containing atmosphere to obtain a ruthenium-lanthanum bimetallic catalyst for the hydrogenation of p-nitrotoluene, and hydrogenation of p-nitrotoluene to produce p-methylcyclohexane In the amine reaction, p-methylcyclohexylamine will be strongly adsorbed on the catalyst, thereby generating a large amount of tar and inhibiting the reaction; the addition of lanthanum has solved the problem of strong adsorption of the catalyst on p-methylcyclohexylamine, reducing the tar Generation volume.

Description

Ruthenium-lanthanum bimetallic catalyst for hydrogenation of p-nitrotoluene and preparation method thereof

technical field

The invention relates to a hydrogenation catalyst and a preparation method thereof, in particular to a hydrogenation catalyst for p-nitrotoluene.

Background technique

P-methylcyclohexylamine is mainly used in the fields of medicine, automobiles, papermaking and catalysis, such as for the synthesis of some drugs that improve human immunity. Secondly, as an intermediate, it is also an inhibitor of spermidine It can be used in the preparation of zeolite catalyst in the catalytic industry; as a good binder component, it can also be used in the retreading of automobile tires and the repair of factory conveyor belts; it can also be used in bleaching pulp and waste paper in the paper industry. In addition, p-methylcyclohexylamine is an intermediate for the production of a new generation of sulfonyl hypoglycemic drug glimepiride, and with widespread attention and attention at home and abroad, it will have broad prospects. At present, there are two main synthetic methods of p-methylcyclohexylamine, one is formed by reduction of p-methylaniline, and the other is formed by direct reduction of p-nitrotoluene. Since the direct hydrogenation of p-nitrotoluene can complete multi-step reactions in one step in the same equipment, it has the advantages of atom economy, high product yield, good quality, low cost, and environmental friendliness, and is increasingly favored by researchers at home and abroad. The difficulty of this hydrogenation reaction is that when the nitro group and the benzene ring are reduced at the same time, the catalyst not only requires high activity, but also has good shape-selective catalytic ability. Deamination leads to a polymerization reaction, which in turn generates macromolecular tar, reduces product purity, and leads to catalyst deactivation. Therefore, the key to research is how to reduce the amount of tar generated under the premise of ensuring high catalyst activity and low cost.

CN99104557.2 discloses a new process of catalytic hydrogenation reduction of substituted aromatic amines, using substituted nitrobenzene as raw material, in organic solvents such as methanol or ethanol, Raney nickel as catalyst, hydrogen as reducing agent, at a certain temperature, The reduction process is achieved under pressure conditions. From the content disclosed in this patent, the catalytic reaction temperature is relatively high, and a large amount of tar is produced when the nitro group is reduced during production.

CN1850330A discloses a kind of adopting conventional impregnation reduction method to prepare supported Ni-B amorphous alloy catalyst, which is used to catalyze the hydrogenation of nitrobenzene, due to the inhomogeneous distribution of the active component precursor in the carrier, and the difference with the carrier The interaction is weak. During the reduction process, the metal ions at the opening of the carrier pores are preferentially reduced, and the formed amorphous alloy will block the pores of the carrier. The excess reducing agent self-decomposes, thereby preventing the reduction of metal ions deposited in the deep pores of the carrier, resulting in a decrease in the content of active components and uneven radial distribution.

CN101439285A discloses a kind of preparation method that is used for carrying out catalytic hydrogenation to nitro compound and prepares the catalyst of corresponding amino compound, the nickel/diatomite catalyst active component content that this method prepares is too high, although it has certain effect in reducing tar It is effective, but the active components are lost a lot and the stability is not high.

Sasson et al. studied the reduction of nitrobenzene and found that the aromatic ring can be reduced with formic acid and palladium-carbon system. Under the protection of nitrogen, the methanol solution of 2 mmol of p-nitrotoluene, Pd/C 50 mg and 0.5 ml of formic acid was at room temperature Stirring for 70 h, the obtained precipitate was extracted with ester, and the final product was separated by capillary column chromatography to obtain 48% p-methylcyclohexylamine, and the product yield was too low (Sasson, Tetrahedron lett, 1992, 49:7477).

Therefore, the research and development of p-nitrotoluene hydrogenation catalysts is the key to catalytic hydrogenation technology. In view of the problems existing in the catalytic hydrogenation process, the present invention prepares A highly active ruthenium-lanthanum bimetallic catalyst that catalyzes the hydrogenation of p-nitrotoluene. The by-product of this reaction is mainly tar, and p-methylcyclohexylamine is an intermediate for generating tar, which will be strongly adsorbed on the catalyst and inhibit the reaction; The added metal lanthanum can weaken the adsorption of the catalyst to the methylcyclohexylamine, reduce the generation of tar, and improve the stability of the catalyst.

Contents of the invention

The object of the present invention is to provide a kind of ruthenium-lanthanum bimetallic catalyst and preparation method thereof for the hydrogenation of p-nitrotoluene.

The present invention is a ruthenium-lanthanum bimetallic catalyst for the hydrogenation of p-nitrotoluene and a preparation method thereof. The ruthenium-lanthanum bimetallic catalyst for the hydrogenation of p-nitrotoluene is composed of ruthenium, lanthanum and a carrier, and the catalyst composition is expressed as: x % Ru- y % La/carrier, where x % represents the mass percentage of Ru in the catalyst, y % represents the mass percentage of La in the catalyst, and the content of each component of the catalyst is Ru: 0.5~5 % by mass percentage, La: 0.2 ~ 2%, the rest is the carrier.

The preparation method of p-nitrotoluene hydrogenation ruthenium-lanthanum double metal catalyst, its steps are:

(1) Prepare a solution with a concentration of 0.3-3.0 mol/L of the soluble compound of the active component Ru with distilled water, add a carrier to the prepared solution, and immerse under strong stirring for 1-5 h to obtain a solution;

(2) The soluble compound of auxiliary agent lanthanum is formulated into B solution with a concentration of 0.3~3.0 mol/L;

(3) Add the prepared B solution directly to the A solution to obtain the C mixed solution, and continue aging for 2-10 h after adding;

(4) The precipitating agent is made into D solution with a concentration of 0.5~3.0 mol/L;

(5) Add the prepared solution D to the mixed solution C dropwise. During the dropping process, the reaction temperature is kept at 40-80 °C, and the aging is continued for 5-20 h after the addition;

(6) Filter and wash the sample obtained in step (5), then dry it at 80-100 °C for 5-12 hours, and then dry it at 110-120 °C for 5-12 hours; grind the dried catalyst to 200 mesh;

(7) The catalyst obtained in step (6) needs to be activated under a hydrogen atmosphere. The specific conditions are: the pressure is 0.1~3 MPa, and the

Reduction at 300-600 °C for 1-10 h, after reduction, lower the temperature to 20-30 °C under the protection of high-purity nitrogen.

The advantages of the invention are: the catalyst has high catalytic activity, high selectivity and good stability. The synthesis method of the catalyst is simple and easy for industrialization.

Description of drawings

Fig. 1 is the TEM figure of ruthenium catalyst,

Figure 2 is a TEM image of the ruthenium-lanthanum bimetallic catalyst.

detailed description

The present invention is a ruthenium-lanthanum bimetallic catalyst for the hydrogenation of p-nitrotoluene and a preparation method thereof. The ruthenium-lanthanum bimetallic catalyst for the hydrogenation of p-nitrotoluene is composed of ruthenium, lanthanum and a carrier, and the catalyst composition is expressed as: x % Ru- y % La/carrier, where x % represents the mass percentage of Ru in the catalyst, y % represents the mass percentage of La in the catalyst, and the content of each component of the catalyst is Ru: 0.5~5 % by mass percentage, La: 0.2 ~ 2%, the rest is carrier, the addition of metal lanthanum improves the problem of strong adsorption of the catalyst to methylcyclohexylamine, and significantly reduces the amount of tar generation.

In the above-mentioned ruthenium-lanthanum bimetallic catalyst for hydrogenation of p-nitrotoluene, the soluble compound of the active component Ru is selected from any one of ruthenium oxide, ruthenium chloride, ruthenium acetate, and ruthenium iodide.

In the above-mentioned ruthenium-lanthanum bimetallic catalyst for hydrogenation of p-nitrotoluene, the soluble compound of the auxiliary agent La is selected from any one of lanthanum oxide, lanthanum chloride, and lanthanum nitrate.

For the above-mentioned ruthenium-lanthanum bimetallic catalyst for hydrogenation of p-nitrotoluene, the carrier is USY molecular sieve, NaY molecular sieve, HY molecular sieve, ZSM-5 molecular sieve.

The preparation method of p-nitrotoluene hydrogenation ruthenium-lanthanum double metal catalyst, its steps are:

(1) Prepare a solution with a concentration of 0.3-3.0 mol/L of the soluble compound of the active component Ru with distilled water, add a carrier to the prepared solution, and immerse under strong stirring for 1-5 h to obtain a solution;

(2) The soluble compound of auxiliary agent lanthanum is formulated into B solution with a concentration of 0.3~3.0 mol/L;

(3) Add the prepared B solution directly to the A solution to obtain the C mixed solution, and continue aging for 2-10 h after adding;

(4) The precipitating agent is made into D solution with a concentration of 0.5~3.0 mol/L;

(5) Add the prepared solution D to the mixed solution C dropwise. During the dropping process, the reaction temperature is kept at 40-80 °C, and the aging is continued for 5-20 h after the addition;

(6) Filter and wash the sample obtained in step (5), then dry it at 80-100 °C for 5-12 hours, and then dry it at 110-120 °C for 5-12 hours; grind the dried catalyst to 200 mesh;

(7) The catalyst obtained in step (6) needs to be activated under a hydrogen atmosphere. The specific conditions are: the pressure is 0.1~3 MPa, and the

Reduction at 300-600 °C for 1-10 h, after reduction, lower the temperature to 20-30 °C under the protection of high-purity nitrogen.

In the preparation method of the above-mentioned ruthenium-lanthanum bimetallic catalyst for hydrogenation of p-nitrotoluene, the precipitating agent is selected from any one of urea, sodium carbonate, ammonium carbonate, urea, potassium carbonate, and ammonium bicarbonate.

In the above-mentioned preparation method of the ruthenium-lanthanum bimetallic catalyst for hydrogenation of p-nitrotoluene, the reduction pressure under the hydrogen atmosphere is 0.1-3 MPa.

In the above-mentioned preparation method of the ruthenium-lanthanum bimetallic catalyst for hydrogenation of p-nitrotoluene, the reduction temperature in a hydrogen atmosphere is 300-600°C.

Comparing Fig. 1 and Fig. 2, it can be seen that the surface of the ruthenium-lanthanum bimetallic catalyst prepared by the present invention has no obvious agglomeration phenomenon, but the agglomeration of the surface active components of the ruthenium catalyst is serious, thereby affecting the catalytic activity of the ruthenium catalyst.

The analysis and evaluation method of each embodiment of the present invention and comparative example is:

1. The activity evaluation was determined by a 0.5 L high-pressure hydrogenation reactor produced by Shandong Weihai Company in China. The raw material p-nitrotoluene was purchased from Shanghai Jingchun Reagent Co., Ltd. Evaluation conditions: weigh 5 g of p-nitrotoluene, weigh 0.5 g of catalyst g. Take 300 mL of isopropanol as the solvent, fill it with hydrogen gas at 3.5 MPa, keep the reaction temperature at 150~160 °C, and rotate at 1000 r/min.

Example 1: Weigh 0.3 g of ruthenium chloride hexahydrate and dissolve it in 70 ml of distilled water. After it is completely dissolved, add 5.7 g of HY molecular sieves and soak it at 70°C for 1 h, then dissolve 0.01 g of lanthanum oxide in 15 ml of distilled water Add the above mixed solution to continue stirring and impregnating for 9 h, then add 0.05mol/L urea aqueous solution dropwise, continue aging for 14 h, filter and wash, then dry at 100 °C for 10 h, and then dry at 120 °C for 10 h Grind the dried catalyst to 200 mesh, and reductively activate the obtained catalyst. The conditions are: reduce with hydrogen (hydrogen pressure: 0.1-2.0 MPa) at 500 °C for 3 h, and then drop to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as 1# catalyst, and 0.5 g of catalyst 1# was taken for activity evaluation.

Example 2: Weigh 0.3 g of ruthenium oxide and dissolve it in 70 ml of distilled water. After it is completely dissolved, add 5.7 g of NaY molecular sieve, soak it at 60°C for 2 h, then dissolve 0.02 g of lanthanum chloride in 20 ml of distilled water, Add to the above mixed solution and continue to stir and impregnate for 5 h, then add dropwise 0.04 mol/L potassium carbonate aqueous solution, continue to age for 17 h, filter and wash, then dry at 95°C for 12 h, and then dry at 110°C for 12 h , the dried catalyst was ground to 200 mesh, and the obtained catalyst was reductively activated under the following conditions: reducing with hydrogen (hydrogen pressure: 0.1-2.0 MPa) at 480 °C for 3 h, and then cooling down to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as 2# catalyst, and 0.5 g of catalyst 2# was taken for activity evaluation.

Example 3: Weigh 0.3 g of ruthenium acetate and dissolve it in 80 ml of distilled water. After it is completely dissolved, add 5.7 g of USY molecular sieves and soak at 80°C for 5 h, then dissolve 0.03 g of lanthanum nitrate in 20 ml of distilled water, add Continue stirring and impregnating in the above mixed solution for 5 h, then add dropwise 0.035 mol/L ammonium carbonate aqueous solution, continue aging for 14 h, filter and wash, then dry at 85°C for 8 h, then dry at 120°C for 12 h; Grind the dried catalyst to 200 mesh, and reductively activate the obtained catalyst. The conditions are: first reduce with hydrogen at 350°C for 1.5 h, then adjust the temperature to 500°C and reduce with hydrogen (hydrogen pressure is 0.1~2.0 MPa) After 1.5h, it was lowered to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as 3# catalyst, and 0.5 g of catalyst 3# was taken for activity evaluation.

Example 4: Weigh 0.3 g of ruthenium chloride hexahydrate and dissolve it in 60 ml of distilled water. After it is completely dissolved, add 5.7 g of NaY molecular sieve, soak it at 80°C for 1 hour, and then dissolve 0.02 g of lanthanum oxide in 20 ml of distilled water , added to the above mixed solution and continued to stir and impregnate for 4 h, then added dropwise 0.03 mol/L ammonium carbonate aqueous solution, continued to age for 19 h, filtered and washed, then dried at 95 °C for 12 h, and then dried at 110 °C for 12 h , grind the dried catalyst to 200 mesh, and reductively activate the obtained catalyst. The conditions are: first reduce with hydrogen at 350°C for 1.5 h, then adjust the temperature to 500°C and reduce with hydrogen (hydrogen pressure is 0.1~2.0 MPa) After 1.5 h, it was lowered to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as 4# catalyst, and 0.5 g of catalyst 4# was taken for activity evaluation. The TEM photo of the 4# catalyst is shown in Figure 1. Due to the addition of lanthanum, there is no large amount of agglomeration on the surface of the Ru catalyst, indicating that the introduction of lanthanum helps the active components to disperse on the surface of the NaY molecular sieve, thereby improving the activity of the catalyst. The evaluation of the hydrogenation reaction of p-nitrotoluene proves that the introduction of lanthanum can also weaken the adsorption of the catalyst to p-methylcyclohexylamine and reduce the generation of tar.

Example 5: Weigh 0.3 g of ruthenium iodide and dissolve it in 50 ml of distilled water. After it is completely dissolved, add 5.7 g of USY molecular sieves, soak at 70°C for 5 h, and then dissolve 0.02 g of lanthanum nitrate in 20 ml of distilled water. Add to the above mixed solution and continue to stir and impregnate for 3 h, then add dropwise 0.04 mol/L ammonium bicarbonate solution, then age for 16 h, filter and wash, then dry at 90 °C for 12 h, and then dry at 110 °C for 12 h. Grind the dried catalyst to 200 mesh, and reductively activate the obtained catalyst. The conditions are: first reduce with hydrogen at 350°C for 1.5 h, then adjust the temperature to 500°C and reduce with hydrogen (hydrogen pressure: 0.1~2.0 MPa) for 1.5 h , dropped to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as 5# catalyst, and 0.5 g of catalyst 5# was taken for activity evaluation.

Example 6: Weigh 0.3 g of ruthenium chloride hexahydrate and dissolve it in 55 ml of distilled water. After it is completely dissolved, add 5.7 g of HY molecular sieves, soak it at 65°C for 2 h, and then dissolve 0.03 g of lanthanum chloride in 20 ml Add distilled water to the above mixed solution and continue to stir and impregnate for 5 h, then add 0.04 mol/L ammonium bicarbonate solution dropwise, then age for 17 h, filter and wash, then dry at 100 °C for 12 h, and then place at 110 °C Dry for 12 hours; Grind the dried catalyst to 200 mesh, and reductively activate the obtained catalyst. The conditions are: reduce with hydrogen (hydrogen pressure: 0.1~2.0 MPa) at 550 ℃ for 3 hours, and drop to room temperature. The obtained catalyst sample was recorded as 6# catalyst, and 0.5 g of catalyst 6# was taken for activity evaluation.

Example 7: Weigh 0.3 g of ruthenium acetate and dissolve it in 80 ml of distilled water. After it is completely dissolved, add 5.7 g of ZSM-5 molecular sieve, soak it at 60°C for 1.5 h, then dissolve 0.03 g of lanthanum oxide in 20 ml of distilled water , added to the above mixed solution and continued to stir and impregnate for 8.5 h, then added dropwise 0.05 mol/L sodium carbonate aqueous solution, continued to age for 14 h, filtered and washed, then dried at 95 °C for 6 h, and then dried at 120 °C for 12 h , the dried catalyst was ground to 200 mesh, and the obtained catalyst was reductively activated under the following conditions: reducing with hydrogen (hydrogen pressure 0.1-2.0 MPa) at 550 °C for 3 hours, and then lowered to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as 7# catalyst, and 0.5 g of catalyst 7# was taken for activity evaluation.

Example 8: Weigh 0.3 g of ruthenium oxide and dissolve it in 75 ml of distilled water. After it is completely dissolved, add 5.7 g of ZSM-5 molecular sieve, soak it at 75°C for 4 h, then dissolve 0.02 g of lanthanum nitrate in 20 ml of distilled water , added to the above mixed solution and continued to stir and impregnate for 10 h, then added dropwise 0.04 mol/L ammonium carbonate solution, then aged for 10 h, filtered and washed, then dried at 85 °C for 12 h, and then dried at 115 °C for 12 h , grind the dried catalyst to 200 mesh, and reductively activate the obtained catalyst. The conditions are: first reduce with hydrogen at 350°C for 1.5 h, and then adjust the temperature to 500°C with hydrogen (hydrogen pressure is 0.1~2.0 MPa) After reduction for 1.5 h, it was lowered to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as 8# catalyst, and 0.5 g of catalyst 8# was taken for activity evaluation.

Comparative example 1: Weigh 0.3 g of ruthenium chloride hexahydrate and dissolve it in 60 ml of distilled water. After it is completely dissolved, add 5.7 g of HY molecular sieves, soak at 80°C for 5 h, then add dropwise 0.03 mol/L ammonium carbonate aqueous solution, Continue to age for 19 h, filter and wash, then dry at 95 °C for 12 h, then place at 110 °C for 12 h, grind the dried catalyst to 200 mesh, and reduce and activate the obtained catalyst. Reduction with hydrogen at 400°C for 2 h, then reduction with hydrogen at 500°C (hydrogen pressure: 0.1-2.0 MPa) for 2 h, and down to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as D1# catalyst, and 0.5 g of catalyst D1# was taken for activity evaluation.

Comparative example 2: Weigh 0.3 g of ruthenium acetate and dissolve it in 65 ml of distilled water. After it is completely dissolved, add 5.7 g of HY molecular sieves, soak at 80°C for 5 h, then add dropwise 0.05 mol/L potassium carbonate aqueous solution, and continue to age for 15 h, filter and wash, then dry at 95°C for 10 h, then dry at 110°C for 12 h, grind the dried catalyst to 200 mesh, and reductively activate the obtained catalyst. Use hydrogen to reduce for 1.5 h, then adjust the temperature to 500°C and use hydrogen to reduce for 1.5 h (hydrogen pressure is 0.1-2.0 MPa), and drop to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as D2# catalyst, and 0.5 g of catalyst D2# was taken for activity evaluation.

Comparative example 3: Weigh 0.3 g of ruthenium oxide and dissolve it in 70 ml of distilled water. After it is completely dissolved, add 5.7 g of HY molecular sieve, soak it at 80°C for 4 h, then add dropwise 0.03 mol/L ammonium bicarbonate aqueous solution, and continue aging After 20 h, filter and wash, then dry at 100 °C for 8 h, and then dry at 110 °C for 12 h, grind the dried catalyst to 200 mesh, and reductively activate the obtained catalyst, the condition is: use at 500 °C Hydrogen (hydrogen pressure is 0.1-2.0 MPa) reduction for 5 h, then dropped to room temperature under the protection of high-purity nitrogen. The obtained catalyst sample was recorded as D3# catalyst, and 0.5 g of catalyst D3# was taken for activity evaluation. The TEM photo of the D3# catalyst is shown in Figure 2. A large number of active components are agglomerated on the surface of the catalyst. The evaluation of the hydrogenation reaction of p-nitrotoluene shows that the catalyst has low activity, which may be due to the lack of introduction of lanthanum. The uneven dispersion of ruthenium particles on the surface of the carrier leads to low selectivity to methylcyclohexylamine due to the adsorption of methylcyclohexylamine by the Ru catalyst, resulting in a deamination reaction to generate a large amount of tar.

Comparative example 4: Weigh 0.3 g of ruthenium iodide and dissolve it in 60 ml of distilled water. After it is completely dissolved, add 5.7 g of HY molecular sieve, soak it at 80°C for 2 h, then add dropwise 0.04 mol/L sodium carbonate aqueous solution, and continue aging After 20 h, filter and wash, then dry at 85°C for 12 h, then dry at 120°C for 10 h, grind the dried catalyst to 200 mesh, and reductively activate the obtained catalyst. The conditions are: use Hydrogen (hydrogen pressure 0.1-2.0 MPa) reduction for 3 h, under the protection of high-purity nitrogen down to room temperature. The obtained catalyst sample was recorded as D4# catalyst, and 0.5 g of catalyst D4# was taken for activity evaluation.

As can be seen from the data in Table 1, the ruthenium-lanthanum bimetallic catalysts synthesized by the preparation methods of Examples 1-8 have higher activity than the supported ruthenium-based catalysts synthesized by the preparation methods of Comparative Examples 1-4. It shows that the introduction of metal lanthanum is beneficial to improve the catalytic activity, selectivity and stability of p-nitrotoluene hydrogenation catalyst.

Claims (8)

1. p-nitrotoluene hydrogenation ruthenium-lanthanum bimetallic catalyst is characterized in that catalyst is made up of ruthenium, lanthanum and carrier, and catalyst composition is expressed as: x % Ru-y % La/ carrier, and x % represents Ru in catalyst The mass percentage in , y% represents the mass percentage of La in the catalyst, and the content of each component of the catalyst is Ru: 0.5~5%, La: 0.2~2%, and the rest are carriers. 2. p-nitrotoluene hydrogenation ruthenium-lanthanum bimetallic catalyst according to claim 1, is characterized in that the soluble compound of active component Ru is selected from arbitrary in ruthenium oxide, ruthenium chloride, ruthenium acetate, ruthenium iodide A sort of. 3. p-nitrotoluene hydrogenation ruthenium-lanthanum bimetallic catalyst according to claim 1 is characterized in that the soluble compound of auxiliary agent La is selected from any one in lanthanum oxide, lanthanum chloride, lanthanum nitrate. 4. The ruthenium-lanthanum bimetallic catalyst for hydrogenation of p-nitrotoluene according to claim 1, characterized in that the carrier is USY molecular sieve, NaY molecular sieve, HY molecular sieve, ZSM-5 molecular sieve. 5. the preparation method of p-nitrotoluene hydrogenation ruthenium-lanthanum bimetallic catalyst is characterized in that, its steps are: (1) Prepare a solution with a concentration of 0.3-3.0 mol/L of the soluble compound of the active component Ru with distilled water, add a carrier to the prepared solution, and immerse under strong stirring for 1-5 h to obtain a solution; (2) The soluble compound of auxiliary agent lanthanum is formulated into B solution with a concentration of 0.3~3.0 mol/L; (3) Add the prepared B solution directly to the A solution to obtain the C mixed solution, and continue aging for 2-10 h after adding; (4) The precipitating agent is made into D solution with a concentration of 0.5~3.0 mol/L; (5) Add the prepared solution D to the mixed solution C dropwise. During the dropping process, the reaction temperature is kept at 40-80 °C, and the aging is continued for 5-20 h after the addition; (6) Filter and wash the sample obtained in step (5), then dry it at 80-100 °C for 5-12 hours, and then dry it at 110-120 °C for 5-12 hours; grind the dried catalyst to 200 mesh; (7) The catalyst obtained in step (6) needs to be activated under a hydrogen atmosphere. The specific conditions are: the pressure is 0.1~3 MPa, and the Reduction at 300-600 °C for 1-10 h, after reduction, lower the temperature to 20-30 °C under the protection of high-purity nitrogen. 6. the preparation method of p-nitrotoluene hydrogenation ruthenium-lanthanum bimetallic catalyst according to claim 5 is characterized in that, precipitation agent is selected from urea, sodium carbonate, ammonium carbonate, urea, salt of wormwood, ammonium bicarbonate any of the 7. the preparation method of p-nitrotoluene hydrogenation ruthenium-lanthanum bimetallic catalyst according to claim 5, is characterized in that, under hydrogen atmosphere, reduction pressure is 0.1～3 MPa. 8. The preparation method of the ruthenium-lanthanum bimetallic catalyst for hydrogenation of p-nitrotoluene according to claim 5, characterized in that the reduction temperature is 300-600 °C under a hydrogen atmosphere.