Study On PtSn/SBA-16 Catalyst For Anaerobic Catalytic Dehydrogenation Of Propane

Low-carbon olefins are widely used in the present,and many industrial products use olefins as raw materials.Therefore,the demand for low-carbon olefins is growing in society today.Propylene is superior to ethylene in many aspects.It is very significant to find high-performance catalysts for the dehydrogenation of propane to propylene.Platinum-based or chromium oxide-based catalysts are most widely used in the commercial dehydrogenation of propane to propylene.Considering the demand for green chemistry,the latter has received less attention due to its greater toxicity.In contrast,platinum-based catalysts have a good industrial application value and have received a lot of research.This thesis prepared Pt Sn/SBA-16 catalyst and tested its activity to study the influence of different platinum-tin ratio to the catalytic activity.In heterogeneous catalysis,the activity of the catalyst is significantly affected by the interaction between the active site and the support.For conventional platinum-tin based catalysts,the support is very important to obtain better catalytic results.In this thesis,SBA-16 supports with different morphology and their supported platinum-tin catalysts were prepared by different methods,and the relationship between their structure,physicochemical properties and catalytic activity were further discussed.The main conclusions of this work are as follows:(1)Pt Sn/SBA-16 catalyst was prepared by adding a template agent F127 and its activity was tested to study the influence of different platinum-tin ratio on the catalytic activity of the catalyst.The content of the active component affected on the activity of the catalyst.The activity of the catalyst was found to be the highest when the Pt/Sn ratio was 1:4 in the catalyst,and the maximum yield was 51.3% at 660 ? However,the selectivity of propylene needs to be improved.(2)For Pt Sn/SBA-16 catalyst,the addition of the dual-templates F127 and P123 during the synthesis of the catalyst revealed a remarkable increase in the selectivity of the catalyst.TEM images found that the arrangement of the pores of the catalyst has been changed and the pores are the staggered structure,and when the Sn content of the auxiliary agent is low,a large propylene yield can be obtained,which has a high practical value.(3)Comparing the catalysts of the above two systems,it is found that the catalyst structure has a great influence on the dehydrogenation activity of propane,and the catalytic activity of the catalyst is changed by adjusting the pore structure of the catalyst by adding CTAB.The specific surface area of Pt0.5/SBA-16(0.2)catalyst when CTAB/F127=0.2 is added can reach 876 m2?g-1.At this time,the large specific surface area provides Sn with a large number of attachment sites.When Sn content is high,it is still distributed evenly,and no aggregation occurs.The catalytic activity of the catalyst is still high when Pt content is same and Sn content is low.The yield is maximized when Pt:Sn=1:1,and the maximum yield is up to 56.7% at 660 ?.