MONOLITHIC STRUCTURED CATALYST FOR CARBON MONOXIDE GASE-PHASE COUPLING TO DIALKYL OXALATE & PREPARATION METHOD AND APPLICATION THEREOF

摘要

Provided was a monolithic catalyst for synthesizing an oxalate by carbon monoxide (CO) gaseous-phase coupling, a preparation method and the use thereof. In the catalyst, a ceramic honeycomb or a metal honeycomb was used as skeletal carrier, metal oxides were used as a carrier coating, precious metals Pt, Pd, Ir, Rh were used as active ingredients, as well as Fe, Co, Ni were used as additives, wherein the carrier coating accounts for 5 to 50 wt. % of the honeycomb carrier; the active ingredients of the catalyst account for 0.1 to 5 wt. % of the carrier coating; the additives of the catalyst account for 0.3 to 10 wt. % of the carrier coating; and the atomic ratio of the active ingredients to the additives was 0.1 to 3. the reaction for synthesizing the oxalate was carried out in a fixed bed reactor, wherein, N2 was used as a carrier gas. The volume ratio of N2:CO:Alkyl nitrite was 20-80:5-60:10-40, and the retention time was 0.5-10 s.

主权项

1. A method for preparing a monolithic structured catalyst for carbon monoxide gas-phase coupling to dialkyl oxalate, comprising:
1) Preparation of the ball milling slurry: Mixing one or various kinds of metal nitrate, hydroxide or oxide: adding dilute nitric acid into the mixture; adjusting the pH of the mixture in the range of 1 to 4; and ball milling the mixture for 1 to 48 hours to get the ball milling slurry for the coating of the supports; 2) Washcoat loading: loading the washcoat on ceramic or metal honeycomb supports using the dip-coating method with ball-milling slurry, followed by a drying process; repeating the dip-coating step until achieving the desired loading; and performing calcination at 900-1300° C. for 1-12 hours to form a washcoat; 3) Active components and additive loading: impregnating the coated support into precursor solutions with one or various active components and additives, after a drying process; and treating the catalyst in a H2 or CO atmosphere for 1-10 hours.