HMS@NiPt@Beta core-shell structure catalytic material and preparation method and application thereof

Abstract

The invention discloses an HMS@NiPt@Beta core-shell structure catalytic material and a preparation method and application thereof. According to the catalytic material, a microporous Beta molecular sieve serves as a core, a mesoporous HMS molecular sieve serves as a shell, NiPt bimetallic nanoparticles are evenly distributed on the surface of the microporous Beta molecular sieve, the core of the microporous Beta molecular sieve is prepared through a hydrothermal synthesis method, niPt bimetallic nanoparticles are loaded on the surface of the microporous Beta molecular sieve through a low-temperature oxygen plasma treatment technology, the mesoporous HMS molecular sieve shell is prepared through a vapor phase crystal transformation method, and based on the total mass of the catalytic material, nickel accounts for 10-30 wt%, platinum accounts for 0.01-5 wt%, the microporous Beta molecular sieve core accounts for 40-60 wt%, and the balance is the mesoporous HMS molecular sieve shell. The catalytic material is applied to a reaction for catalyzing dehydrogenation coupling of pyridine to synthesize 2, 2'-dipyridyl, has the advantages of low dosage, few side reactions, short process and the like, and has a good application prospect in the fields of adsorption separation, petrochemical engineering, fine chemical production and the like.

Description

technical field [0001] The invention belongs to an industrial catalytic material and a preparation method thereof, in particular to an HMS@NiPt@Beta core-shell structure catalytic material, a preparation method and application thereof. Background technique [0002] 2,2'-Bipyridyl is an important intermediate in chemical production. Because of its bidentate ligand, it has a very wide range of applications in the fields of medicine, pesticides, biology, and natural products. The synthesis of 2,2'-bipyridine has always been a research hotspot in organic chemistry, medicinal chemistry and catalytic chemistry. At present, there are two main methods for the synthesis of 2,2'-bipyridine. The first method is the crossover of 2-chloropyridine Coupling, although this method is relatively mature in industry, it requires pre-chlorination and chlorine removal at the 2-position of pyridine, which increases the synthesis cost of 2,2'-bipyridine and brings greater environmental problems, I...

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Problems solved by technology

The synthesis of 2,2'-bipyridine has always been a research hotspot in organic chemistry, medicinal chemistry and catalytic chemistry. At present, there are two main methods for the synthesis of 2,2'-bipyridine. The first method is the crossover of 2-chloropyridine. Coupling, although this method is relatively mature in industry, it requires pre-chlorination and chlorine removal at the 2-position of pyridine, which increases the synthesis cost of 2,2'-bipyridine and brings greater environmental problems, In contrast, the second method is the direct dehydrocoupling of pyridine, since no pretreatment of pyridine is required, the reaction only produces H 2 The only by-product, so this method has high atomic efficiency and is environmentally friendly, but the existing catalyst Raney nickel in the direct dehydrogenation coupling reaction of pyridine has problems such as easy spontaneous combustion, low conversion rate, and poor stability, so the development of a Efficient direct dehydrogenation coupling of pyridine to prepare 2,2'-bipyridine catalytic materials has important theoretical significance and application prospects

[0004] At present, there are many technologies for encapsulating bimetallic catalysts with molecular sieves. Chinese patent CN201911232183.9 discloses a method of preparing Mn, Ce, Fe, Co, Ni, La, Ga, W modified MFI@MFI core-shell type by secondary hydrothermal synthesis The molecular sieve catalyst and its preparation method realize the loading of metals on the MFI core, but in the secondary hydrothermal synthesis process, the metal and the molecular sieve core are easily dissolved or etched by the molecular sieve shell synthesis solution, resulting in the loss of metal active components and the stability of the catalyst The property is reduced; Chinese patent CN201610816697.9 discloses a method for preparing a metal-containing core-shell molecular sieve. During the preparation process, the molecular sieve core is used as the silicon source of the shell molecular sieve, which will lead to a decrease in the stability of the molecular sieve core, and the metal in the shell molecular sieve Added in situ during the preparation process, the distribution position of the metal in the core-shell molecular sieve lacks effective control

[0005] Most of the reported core-shell molecular sieve-supported metal catalysts are prepared by secondary hydrothermal synthesis, which ignores the influence of the secondary hydrothermal process on the stability of the core molecular sieve, and lacks the control of the distribution of metals in the molecular sieve.

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