Catalyzer for CO low-voltage gas-phase synthesizing of oxalic ester and method of preparing the same

Abstract

The present invention belongs to the oxalate preparation technical field and aims to provide a catalyst for synthesis of low pressure, high activity and high selectivity oxalate in a CO low-pressure gas phase, and a preparation method for the catalyst. The catalyst mainly uses the palladium metal as a main activated component, titanium and cerium as a promoter, and modified Alfa-Al2O3 as a carrier. The select content of palladium metal is 0.1 to 3.0 percent of the carrier weight, the content of the titanium metal is 0.02 to 1.5 percent of the carrier weight, and the content of the cerium metal is 0.01 to 0.75 percent of the carrier weight. The catalyst is manufactured with the method of immersion. The catalyst is manufactured with the method of immersion. Proven by experiments, the catalyst of the present invention is provided with the very high reaction activity and oxalate selectivity in the reaction to synthesize dimethyl oxalate or diethyl oxalate with carbon monoxide and nitrite. Moreover, the catalyst can resist affection by oxygen, hydrogen, water steam and other impurities. The catalyst is provided with the long usable life and the stable reaction performance, and can be easily controlled.

Description

technical field

[0001] The invention belongs to the technical field of oxalate preparation, and further relates to a catalyst for CO low-pressure gas-phase synthesis of oxalate and a preparation method thereof. Background technique

[0002] Oxalate is an important chemical raw material, which can be used to prepare oxalic acid, ethylene glycol, carbonate, oxalamide, oxalyl chloride, intermediates of drugs and dyes, plastic accelerators and solvents, etc.

[0003] At present, the method of esterification and dehydration of oxalic acid and alcohol (methanol, ethanol, etc.) with toluene as a dehydrating agent is still used in China to produce dialkyl oxalate (dimethyl oxalate, diethyl oxalate). One of its main raw materials, oxalic acid, is produced by the sodium formate method. Sodium formate is synthesized by CO and sodium hydroxide at 160°C and a pressure of 1.56-1.96MPa, and then concentrated and dehydrogenated at 400°C to form sodium oxalate, which is then reacted with lea...