Method for catalytic preparation of delta-valerolactone by using supported nano-gold catalyst

Abstract

The invention pertains to the technical field of chemical industry, in particular to a preparation method of delta-valerolactone by using the load-type nano-gold catalyst. The using catalyst of the invention adopts a deposition precipitation method for preparation, in particular to the Au / TiO2 catalyst with the nano size after the calcination synthesis at certain temperature and the deposition of gold on the titanium dioxide. The catalyst is characterized by good dispersion of activity, small particles of gold and good stability, and can be used for catalytic air direct oxidation of 1, 5-pentanediol for the preparation of delta-valerolactone, so as to realize the one-step oxidation of 1, 5-pentanediol, further to generate the delta-valerolactone. The air is used as the oxidant during the oxidation process of 1, 5-pentanediol to replace the strong oxidants in the traditional methods, such as peracid, halogen oxides, nitrogen oxides and so on, thus avoiding the violent reaction conditions and the pollution substances generated by oxidants, which is in line with the requirements of green chemistry. The catalyst has the advantages of easy recovery and regeneration, can maintain a higher activity after a plurality of repeated uses and has higher industrial application value.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for directly oxidizing 1,5-pentanediol with a supported nano-gold catalyst to prepare delta-valerolactone in one step. Background technique [0002] δ-valerolactone is an important organic intermediate widely used in the synthesis of various biochemical products such as fibers, drugs, spices and pesticides. δ-valerolactone can be synthesized by using 1,5-pentanediol as a raw material. In the traditional process, strong oxidants such as peracids, halogen oxides, nitrogen oxides or composite oxides are often used. The operation is dangerous, expensive, and reactive. A large amount of pollutants are generated, which does not meet the requirements of green chemistry and sustainable development. From the point of view of green chemistry, a clean oxidant must be selected. Air is an ideal oxidant because it is cheap and easy to obtain, and does not produ...

AI Technical Summary

Problems solved by technology

There are two kinds of catalysts commonly used in the process of preparing δ-valerolactone from 1,5-pentanediol. One is a ruthenium complex catalyst. Expensive, not suitable for industrial production; the other is copper-based catalyst, but generally need to add chromium to achieve higher activity, chromium is a highly toxic substance, does not meet the requirements of green chemistry, and the reaction temperature is higher

Gold has always been considered a chemically inert metal, and its catalytic activity is far less active than that of platinum group metals. However, recent studies have found that when gold is dispersed in nanometer size, it is an excellent catalyst. High activity and selectivity have been shown in the oxidation reaction. Although the selective oxidation of 1,5-pentanediol to prepare lactone has important significance, it has not been reported yet.