Nickel-based dehydrogenation catalyst with core-shell structure and preparation method of catalyst

Abstract

The invention relates to a nickel-based dehydrogenation catalyst with a core-shell structure and a preparation method of the catalyst. The preparation method of the catalyst comprises the following steps of: preparing Ni / Cu-MOF; removing Cu in the Ni / Cu-MOF through etching according to the Pearson soft and hard acid-base principle to obtain a Ni / Cu-MOF etching object; adding aluminum salts; growing Ni-Al LDH on the Ni-MOF skeleton of the Ni / Cu-MOF etching object in situ under an alkaline condition so as to obtain an LDH-MOF derivative; and finally, in N2 atmosphere, calcining the LDH-MOF derivative at the temperature of 400 to 600 DEG C so as to obtain the nickel-based dehydrogenation catalyst with the core-shell structure. The inner core of the catalyst is a Ni carbonyl compound active component with the diameter of 10-100 nm; the shell of the catalyst is Ni-Al LDH with the shell thickness of 20-100 nm; and the catalyst can be applied to reactions such as electrolytic hydrogen evolution reaction and bipyridine preparation through pyridine dehydrogenation and has excellent dehydrogenation catalytic performance.

Description

technical field [0001] The invention relates to a nickel-based dehydrogenation catalyst with a core-shell structure and a preparation method thereof, belonging to the catalyst preparation technology in the technical field of industrial catalysis. Background technique [0002] The dehydrogenation reaction of hydrocarbons is a relatively common type of chemical reaction used in the petrochemical field, such as dehydrogenation of alkanes, dehydrogenation of olefins, side chain dehydrogenation of aromatics and dehydrogenation of alcohols. It has been reported that Ni-based catalysts show good catalytic activity in dehydrogenation reactions, and Ni-based catalysts have the advantages of high activity, low price and safe operation, so they have become the first choice in the field of dehydrogenation catalysis. Chinese patent CN101912781A discloses a method for preparing a dehydrogenation nickel-based / diatomite catalyst, which exhibits excellent catalytic activity in catalyzing the...

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Problems solved by technology

[0004] 2,2'-Bipyridine is an important "three-drug" intermediate and raw material for the preparation of photoelectric materials. The current synthesis methods mainly include pyridine carbonyl compound cyclization method, Ullmann method, sodium ammonia method, alkyne amine ring method, decarboxylation method, Oxidation method, alkyne nitrile ring method, pyran ammoniation method and pyridine dehydrogenation one-step direct coupling method, etc. Among them, Ullmann method and direct dehydrogenation coupling method have industrial application prospects, but Ullmann method needs to carry out halogenation to pyridine first. 2-halopyridine, then dehydrogenated and coupled to synthesize 2,2'-bipyridine, there are problems such as low production efficiency, many side reactions, and many wastes

The pyridine one-step direct dehydrogenation coupling method has the characteristics of short process and green environmental protection, and has become a research hotspot and difficulty. At present, Raney nickel is mainly used as the dehydrogenation catalyst, but Raney nickel is very easy to spontaneously ignite and has great safety hazards. It is carried out under anhydrous conditions, the operating conditions are harsh, and the catalyst Raney nickel is easily deactivated. Compared with the Raney Ni catalyst, the supported Ni-based catalyst has the advantages of easy preparation, low price, and safe operation. It is used as a pyridine dehydrogenation system. 2,2'-bipyridine catalyst is a suitable choice, and Ni-based supported catalyst catalyzes the reaction of pyridine dehydrogenation to 2,2'-bipyridine, due to the limitation of the reaction itself, the nitrogen atom in 2,2'-bipyridine Stronger electronegativity will form a strong coordination bond with Ni, making it difficult for the generated 2,2'-bipyridine to desorb from the catalyst or fall off with Ni, resulting in catalyst loss and reduced catalytic performance. Single-pass conversion and 2,2-bipyridine yield are generally very low, and 2,2'-bipyridine single-pass yield is generally less than 1%

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