Catalyst for low-temperature gaseous phase synthesis of benzaldehyde and preparation method thereof

Abstract

The invention discloses a catalyst for low-temperature gaseous phase synthesis of benzaldehyde and a preparation method thereof. The molecular formula of the catalyst is M-Ag-HMS, wherein M is alkali metal, alkaline earth metal or rare earth metal element. The preparation method comprises the following steps of: dissolving primary amine RN serving as a template agent into absolute ethanol to obtain primary amine ethanol solution; preparing mixed solution of silver and potassium nitrate, adding the mixed solution into the primary amine ethanol solution, stirring the solution uniformly till a colloidal material is produced, dripping ethyl orthosilicate into the colloidal material with violent stirring, continuously stirring the colloidal material till sediment is generated, and performing crystallization, filtration, washing, drying, roasting, tabletting and screening to obtain the catalyst. The catalyst has the advantages of high catalytic activity, strong selectivity, simple synthesisprocess, stable structure and long life; when the catalyst is filled in a fixed bed reaction kettle to synthesize benzaldehyde by gaseous phase catalytic oxidation of benzyl alcohol, the reaction conditions are mild, the purity of the product is high, and the costs of separation and purification are reduced; and the catalyst is easy for reclamation and regeneration.

Description

technical field

[0001] The invention relates to a catalyst for low-temperature gas phase synthesis of benzaldehyde, which is a composite modified HMS catalyst. The invention also relates to a preparation method of the catalyst. Background technique

[0002] Benzaldehyde is an important fine chemical and organic intermediate, widely used in the fields of pharmaceuticals, dyes, cosmetics and polymer synthesis. Benzaldehyde (carbonyl compound) is a product of alcohol oxidation. It is unstable under oxidation conditions and is often continuously oxidized, especially aldehydes are more likely to be oxidized to carboxylic acids. Therefore, the selective oxidation of alcohols to aldehydes is a very challenging topic, and the development of highly selective and efficient alcohol oxidation methods has attracted increasing attention. Currently, with H 2 o 2 , O 2 Or air as a clean oxidant, the reaction system is mainly liquid-phase homogeneous and heterogeneous oxidation...