A method for photocatalytic synthesis of ammonia

Abstract

The invention provides a method for synthesizing ammonia through photocatalysis. According to the invention, water is added in a reaction vessel, a catalyst is added in the reaction vessel, a mixture is subjected to ultrasonic mixing, nitrogen is introduced, magnetic stirring is kept, the uniformly stirred mixture is put under illumination condition, a sample is taken, the catalyst is separated, and the concentration of NH4<+> in a solution is analyzed by an indophenol blue spectrophotometry method. The method for synthesizing ammonia through photocatalysis realizes ammonia synthesis under normal temperature and normal pressure, yield can reach as high as 12019.2 grams which is equal to 8289 times of an industrial value standard provided by Schrauzer, and the requirements for industrial production on cost aspect, environmental protection aspect, and technology aspect can be completely satisfied.

Description

technical field [0001] The invention relates to a method for synthesizing ammonia, in particular to a method for photocatalytically synthesizing ammonia. Background technique [0002] Ammonia is an important chemical raw material, and it is widely used in fields such as the plastics industry, the alkali manufacturing industry, and the fertilizer industry. German chemist Haber (F·Haber) solved the problems of reaction conditions, catalysts, and mechanical equipment, and successfully used The thermodynamically favorable direct synthesis of ammonia was achieved on an industrial scale, which became a milestone in the history of the chemical industry and won the Nobel Prize in Chemistry in 1918. The requirements are relatively strict, and the conversion rate of ammonia gas is only 10% to 15% in the Haber ammonia production process, and the production process has high energy consumption, heavy pollution, and high cost. Therefore, for a long time, how to realize it under relatively...

AI Technical Summary

Problems solved by technology

However, this method needs to consume a large amount of electric energy, and the production cost is too high. Moreover, it needs to use electrolyte solution in the production process, which will produce a large amount of industrial waste water and cause serious impact on the environment. Therefore, it has great potential in industrial applications. Great limitations, unable to carry out large-scale industrial production

[0004] In 1977, G.N.SChrauzer of the University of California, San Diego, and others successfully synthesized ammonia by using nitrogen and water under light irradiation on the catalyst, but the preparation efficiency of ammonia was very low, and the purpose of industrial production could not be achieved.

In recent years, there have been many researches on photocatalytic synthesis of ammonia, but the catalysts selected are metal metal oxides or metal oxides loaded with noble metals. The experimental data of ammonia production is mostly several hundred micrograms per gram per catalyst. Although it can reach the industrial value standard, but The production rate is still low, making the production cost too high, so it has not achieved large-scale industrialization

[0005] The existing photocatalytic ammonia synthesis technology usually mixes the raw materials and then reacts under photocatalytic conditions. If the reaction time exceeds two hours, the catalyst activity will be greatly reduced, and it will be lost. It must be treated before the reaction can be continued. cost of production