Monatomic rhodium catalyst, and preparation and applications thereof

Abstract

The invention relates to a preparation method of a monoatomic rhodium catalyst used for catalyzing alkene hydroformylation reaction to generate branched chain aldehydes and olefine aldehydes. Applications of the monoatomic rhodium catalyst are capable of realizing a whole new reaction approach, tandem of alkene hydroformylation reaction and aldol condensation reaction is realized without adding ofadditional acid or base, and one-step of production of branched chain aldehydes and olefine aldehydes from alkenes and synthetic gas is realized. The main active component of the monoatomic rhodium catalyst is rhodium; rhodium is dispersed on a carrier in atom grade; the mass amount of rhodium accounts for 0.005 to 2wt% of the total mass amount of the monatomic rhodium catalyst. The monoatomic rhodium catalyst is relatively high in catalytic activity and stability in alkene hydroformylation reaction; under the optimum reaction conditions, branched chain aldehyde product selectivity is 95% orhigher. The monoatomic rhodium catalyst is low in economical and environment cost; production separation is convenient; post-treatment is simple; and the application prospect is promising.

Description

technical field [0001] The invention belongs to the field of catalysts, and in particular relates to a single-atom rhodium-based catalyst for catalyzing olefin hydroformylation to generate branched chain aldehydes and alkenals, as well as its preparation method and application. Background technique [0002] The hydroformylation reaction refers to the reaction of olefins and synthesis gas (CO+H 2 ) is the process in which raw materials generate aldehydes under the action of a catalyst. Syngas is produced through coal gasification, and the target product, aldehyde, is a class of fine chemicals with high added value, which can be used to produce chemical products such as resins, plasticizers, rubber antioxidants, gasoline additives, etc. [0003] Since Union Carbide built the world's first low-pressure hydroformylation of propylene to butyraldehyde catalyzed by rhodium-phosphine complexes in 1976, the high activity of Rh-based homogeneous catalysts under mild conditions has be...

AI Technical Summary

Problems solved by technology

However, there are still many problems in this process: 1. Use a large amount of phosphorus-containing ligands; 2. The homogeneous catalyst used is difficult to be recovered and reused, and has certain pollution to the product

Although supported catalysts can be easily recycled, the biggest common problem of this type of rhodium-based nanoparticle catalysts is that only the atoms exposed on the surface of the nanoparticles can really play a catalytic role when a reaction occurs, and more than half of the rhodium atoms Coated inside the particles, so the actual utilization of rhodium is very low, resulting in poor reactivity

However, in the key process of catalyzing aldol condensation, it is inevitable to use strong alkali, which is not only corrosive to equipment, but also causes harm to the environment due to the discharge of strong alkali

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