Study On PtSnNa Catalyst For Propane Anaerobic Dehydrogenation

Propylene is a widely used chemical raw material,because of the continuous development of modern society industry.The demand for propylene has begun to increase,and the market has appeared in short supply phenomenon.Propane dehydrogenation process is a new type of propane production process with many advantages.catalysts with platinum or chromium as the main active components have been widely used in this process.Because of the demand of green chemistry in the world today,platinum-based catalysts have more development prospects and has been widely concerned.In platinum-based catalysts,platinum as the main component,the application is very important,but platinum as a precious metal price is high.The reserves are so small,that it is of great practical significance to reduce the loading amount of platinum.At the same time,the single platinum components can not meet the requirements of industrial application,so the choice of additives is very important.Tin is the most commonly used additive,but the performance of platinum tin catalyst still need be improved and promoted.The support also plays a very important role in the effect of the catalyst.The SBA-15 molecular sieve carrier and its supported platinum tin and platinum tin sodium catalysts were prepared in this thesis.The preparation,reaction conditions and the effect of the third catalyst component were studied.(1)The Pt0.3/SBA-15 catalyst with low loading amount was firstly prepared and tested at different temperatures.The results showed that the maximum yield of propylene could be obtained at 580℃.(2)The effects of Sn loading and catalyst calcination temperature on the performance of the Pt0.3Sn/SBA-15 catalyst were studied.The experimental results show that the propane conversion is the highest when the loading amount of Sn is 0.6%,and the catalyst performance is the best when the calcination temperature is 550℃.(3)PtSnNa/SBA-15 catalysts were prepared and characterized.Their physicochemical properties and activities were detected.The activity test shows that the maximum propylene yield can be obtained when the loading amount of Na is 0.6%,and the initial propylene yield can reach 50%at this time.but the catalyst stability has not reached the expected,and further research has still improved..