Iridium picolinate complex catalyst for synthesizing acetic acid by methanol carbonylation

Abstract

The invention discloses an iridium picolinate complex catalyst for synthesizing acetic acid by methanol carbonylation and a preparation method and an application thereof, a ligand of the catalyst is a copolymer of 2-vinyl pyridine and methyl acrylate, and a copolymer iridium complex catalyst is formed by the complexation reaction with an iridium compound. The preparation method comprises the steps of preparing the ligand of the catalyst, then dissolving 1 part by weight of the copolymer in 10-100 parts by weight of the acetic acid, stirring, heating under reflux, adding the iridium compound which accounts for 3-10% of the weight of the copolymer, carrying out reaction for 10-60min, cooling to the room temperature, using ether for precipitation, filtering and then obtaining a copolymer iridium catalyst. The 1 part by weight of the copolymer is added into the acetic acid solution containing (Ir(CO)2I)2 or (Ir(CO)2Cl)2 under stirring, the feeding is 3-10% of the weight of the copolymer calculated by the weight of iridium, the reaction is carried out for 10-30min under stirring, the ether is used for precipitation, and the copolymer iridium catalyst is obtained by filtering. The copolymer iridium catalyst is used for preparing the acetic acid by methanol carbonylation reaction and has good catalytic performance.

Description

technical field [0001] The invention belongs to the field of methanol carbonylation reaction to prepare acetic acid, and in particular relates to the catalyst and its preparation method. Background technique [0002] Methanol carbonylation reaction to prepare acetic acid is currently the most widely used and most advanced technical route in industry. From the invention of the original Monsanto Company (US3 769 329) to the high-iodine low-water reaction system (US5 001 259, EP055618) of Celanes Company, rhodium is used as the catalyst active component. Due to the high price of rhodium, the research on non-rhodium-based catalysts has always been a hot topic, the most successful of which is the application of iridium-based catalysts (EP0749948, EP0752406) in industrial production. This technology was developed by BP Chemical Company in 1996, called Catva process. Compared with rhodium-based catalysts, iridium-based catalysts have the advantages of low price and less reaction b...

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Problems solved by technology

[0004] There are a lot of reports about the rhodium catalyst supported by polymer resin used in methanol carbonylation to prepare acetic acid. Usually this type of heterogeneous catalytic system has a certain effect on the improvement of catalytic performance in some aspects, but due to gas, solid and liquid The limitation of the phase reaction system; it is inconvenient to the separation and circulation of the reaction product, especially for the direct application of the current industrial device