Preparation method of high-activity palladium-carbon catalyst

Abstract

The invention discloses a preparation method of a high-activity palladium-carbon catalyst. The preparation method comprises the following steps of: (1) treating active carbon by using a compound oxidizing agent mixed solution; (2) slowly adding a palladium-chloride solution into the treated active carbon to obtain a mixed solution, and carrying out ultrasonic dispersion on the mixed solution; (3) adding alkali metal hydroxide or carbonate into the mixed solution ultrasonically dispersed to precipitate palladium ions, then adding a reducing agent, washing and drying to obtain a solid catalyst; and (4) carrying out plasma treatment on the solid catalyst to obtain a finished palladium-carbon catalyst. The preparation method disclosed by the invention has the advantages that compared with the traditional nitric acid, the high-activity palladium-carbon catalyst is environment-friendly and low-pollution; due to utilization of ultrasonic treatment, the dispersion of the catalyst is more uniform; and final plasma treatment is carried out on the catalyst, so that the activity of the catalyst is further improved.

Description

technical field [0001] The invention belongs to the field of supported noble metal catalysts, and in particular relates to a preparation method of a highly active palladium-carbon catalyst. The palladium-carbon catalyst is suitable for general hydrogenation reaction systems, and is particularly suitable for the hydrogenation of disproportionated rosin and cinnamaldehyde in the disproportionation of rosin. application. Background technique [0002] As we all know, palladium-carbon catalysts are widely used in medicine and chemical industry, especially in the hydrogenation of terephthalic acid, hydrogenation of unsaturated aldehydes and disproportionation of rosin. The present invention is mainly aimed at the improvement of the palladium-carbon catalyst preparation process, improves the dispersibility and stability of palladium in the pretreatment mode of activated carbon, ultrasonic-plasma technology, etc., and greatly improves the catalytic activity and Palladium utilizatio...

AI Technical Summary

Problems solved by technology

Generally, coconut shell activated carbon contains less impurities and has high mechanical strength, but the price is relatively expensive and the pore size is small. It is generally more suitable for loading precious metals.

Keith et al describe in the US3138560 patent that there are some reducing groups on the surface of activated carbon such as aldehyde groups, free electrons and some impurity elements or ions. If the activated carbon is not treated, these reducing groups will directly reduce the palladium salt to form Shiny metal palladium film, causing metal migration and grain growth, resulting in poor catalyst activity