阅读说明：本技术 一种负载贵金属催化剂的分子筛的制备及应用 (Preparation and application of noble metal catalyst-loaded molecular sieve ) 是由 刘飞 于 2019-12-10 设计创作，主要内容包括：本发明涉及一种负载贵金属催化剂的分子筛的制备及应用。该负载贵金属催化剂的分子筛的制备,配置四丙基溴化铵溶液、HMDA溶液、NaOH溶液各一份,按质量比1：1：1混合搅拌,并加入硼酸；将上述溶液加入至晶化釜中晶化,并对晶体进行抽滤、洗涤以及干燥；将上述步骤得到的固体置于300-700℃下焙烧,焙烧完成后收集；配置贵金属酸溶液或盐溶液,将上述的固体物置于溶液内,搅拌；将上述稠状物烘干后焙烧；冷却后得到负载贵金属催化剂的干燥物；该分子筛应用,包括需要先将分子筛活化,再将其通入甲醇溶液中,并通入惰性气体后气化甲醇溶液,最后将气体通入反应器进行反应得到分子筛,该分子筛活性高,负载量大,分子筛面积相对大,便于人们的使用。(The invention relates to a preparation method and application of a molecular sieve loaded with a noble metal catalyst. The preparation method of the noble metal catalyst-loaded molecular sieve comprises the steps of preparing tetrapropylammonium bromide solution, HMDA solution and NaOH solution in parts by mass ratio of 1: 1: 1, mixing and stirring, and adding boric acid; adding the solution into a crystallization kettle for crystallization, and performing suction filtration, washing and drying on crystals; roasting the solid obtained in the step at the temperature of 300-700 ℃, and collecting the roasted solid; preparing a noble metal acid solution or a salt solution, putting the solid into the solution, and stirring; drying the thick substance and then roasting; cooling to obtain a dried substance carrying the noble metal catalyst; the molecular sieve is applied by activating the molecular sieve, introducing the molecular sieve into a methanol solution, introducing inert gas, gasifying the methanol solution, and introducing the gas into a reactor for reaction to obtain the molecular sieve.)

1. The preparation method of the molecular sieve loaded with the noble metal catalyst is characterized by comprising the following steps:

s1: preparing tetrapropylammonium bromide solution, HMDA solution and NaOH solution, and mixing the four solutions according to the mass ratio of 1: 1: 1, mixing and stirring, and adding boric acid;

s2: adding the solution into a crystallization kettle for crystallization, and performing suction filtration, washing and drying on crystals;

s3: roasting the solid obtained in the step at the temperature of 300-700 ℃, and collecting the roasted solid;

s4: preparing a noble metal acid solution or a salt solution, putting the solid into the solution, and stirring;

s5: drying the thick substance and then roasting;

s6: and cooling to obtain a dried product carrying the noble metal catalyst.

2. The preparation method of the noble metal catalyst-supported molecular sieve according to claim 1, wherein: s1: the temperature of the stirring condition is controlled to be 60-90 ℃.

3. The preparation method of the noble metal catalyst-supported molecular sieve according to claim 1, wherein: s2: the crystallization temperature in the step 2 is 140-170 ℃, and the crystallization time is 48-96 h.

4. The preparation method of the noble metal catalyst-supporting molecular sieve according to claim 3, wherein: s2; and the drying mode in the step 2 is air cooling.

5. The preparation method of the noble metal catalyst-supported molecular sieve according to claim 1, wherein: s3: the temperature for roasting the solid particles is controlled at 600 ℃.

6. The preparation method of the noble metal catalyst-supported molecular sieve according to claim 1, wherein: s5: the drying temperature is 90-110 ℃, and the drying time is 5 h.

7. The method for preparing the noble metal catalyst-supported molecular sieve according to claim 6, wherein: s5: the roasting time is 5h, and the roasting temperature is 500-600 ℃.

8. The preparation method of the noble metal catalyst-supported molecular sieve according to claim 1, wherein: s4: when preparing acid solution or salt solution, adding active assistant.

9. The preparation method of the noble metal catalyst-supported molecular sieve according to claim 1, wherein: s7: and introducing hydrogen into the dried substance obtained in the S6 at the temperature of between 250 and 600 ℃ for reduction for 8 hours.

10. The use of the noble metal catalyst-supporting molecular sieve of claim 1, wherein: firstly, activating the molecular sieve at 500 ℃ for 3h, then introducing the molecular sieve into a methanol solution, introducing inert gas, gasifying the methanol solution, and finally introducing the gas into a reactor for reaction to obtain the molecular sieve.

Technical Field

The invention belongs to the technical field of catalysts, and particularly relates to preparation and application of a noble metal catalyst-loaded molecular sieve.

Background

The studied catalysts for preparing the molecular sieve by methanol dehydrogenation comprise a metal catalyst, a metal oxide catalyst, an alkali metal insoluble salt catalyst and a molecular sieve catalyst, but all of the catalysts have certain defects, so that the industrial application of the catalysts is limited.

Disclosure of Invention

The invention aims to solve the problems and provide a preparation method and application of a molecular sieve which has higher activity and is reasonably designed and used for supporting a noble metal catalyst.

The invention realizes the purpose through the following technical scheme:

the preparation method of the noble metal catalyst supported molecular sieve comprises the following steps:

s1: preparing tetrapropylammonium bromide solution, HMDA solution and NaOH solution, and mixing the four solutions according to the mass ratio of 1: 1: 1, mixing and stirring, and adding boric acid;

s2: adding the solution into a crystallization kettle for crystallization, and performing suction filtration, washing and drying on crystals;

s3: roasting the solid obtained in the step at the temperature of 300-700 ℃, and collecting the roasted solid;

s4: preparing a noble metal acid solution or a salt solution, putting the solid into the solution, and stirring;

s5: drying the thick substance and then roasting;

s6: and cooling to obtain a dried product carrying the noble metal catalyst.

As a further optimization scheme of the present invention, S1: the temperature of the stirring condition is controlled to be 60-90 ℃.

As a further optimization scheme of the present invention, S2: the crystallization temperature in the step 2 is 140-170 ℃, and the crystallization time is 48-96 h.

As a further preferable aspect of the present invention, S2; and the drying mode in the step 2 is air cooling.

As a further optimization scheme of the present invention, S3: the temperature for roasting the solid particles is controlled at 600 ℃.

As a further optimization scheme of the present invention, S5: the drying temperature is 90-110 ℃, and the drying time is 5 h.

As a further optimization scheme of the present invention, S5: the roasting time is 5h, and the roasting temperature is 500-600 ℃.

As a further optimization scheme of the present invention, S4: when preparing acid solution or salt solution, adding active assistant.

As a further optimization scheme of the present invention, S7: and introducing hydrogen into the dried substance obtained in the S6 at the temperature of between 250 and 600 ℃ for reduction for 8 hours.

The application of the molecular sieve loaded with the noble metal catalyst comprises the steps of activating the molecular sieve at 500 ℃ for 3 hours, introducing the molecular sieve into a methanol solution, introducing inert gas, gasifying the methanol solution, and finally introducing the gas into a reactor for reaction to obtain the molecular sieve.

The invention has the beneficial effects that: according to the invention, the molecular sieve with low silicon-boron ratio is prepared, and the molecular sieve is used for loading the noble metal catalyst, so that the surface area of the molecular sieve is improved, the noble metal catalyst has good dispersibility and higher activity, and the catalyst layer is easier to adsorb due to the increased surface area, thereby reducing the requirement of noble metal, reducing the preparation cost and facilitating the improvement of the reaction efficiency for preparing the molecular sieve.

Detailed Description

The following detailed description of the present application is provided to enable any person skilled in the art to make or use the present application without any intention to limit the scope of the present application