Study On Platinum Catalyst For Catalytic Dehydrogenation Of Propane To Propylene

Propylene, only less important than ethylene, is the most important chemical rawmaterials, which lead to growing demand. Propylene obtained by traditional methodscan not meet the needs of the market, as well as take advantage of light alkanesresource, the research of propane dehydrogenation to propylene becomes a keyresearch field in petrochemical industry.In this work, the effects of In and Ce promoters to the different systemsplatinum-based catalyst are investigated. Meanwhile, the dehydrogenationperformance of platinum-indium catalysts supported on calcined hydrotalcite carrieris investigated. The catalyst structure and properties of carbon is investigated withseveral state-of-art characterizations.1. The propane catalytic performance of PtSn/y-AbOa catalysts by dopingindium is investigated. Indium oxide on the surface of the carrier has a strongneutralizing effect. There is a certain interaction between the platinum and indiumoxide> tin oxide, and the carrier. In and Sn are part of the reduction and the oxidationstate of tin has a slight inhibition by indium oxide. TEM micrographs of the catalystscan be clearly seen that the smallest platinum particle and the best dispersed is thePtSnln trimetallic catalyst. When the indium loading is1.5wt.%, the propaneconversion, selectivity and catalytic stability are the most satisfied for PtSn/1.5In-Alcatalyst. Compared with0.3PtSn/1.5In-Al catalyst, the dehydrogenation performanceof0.6PtSn/1.5In-Al catalyst is better. In other words, the more activity sites for0.6PtSn/l.5In-Al should be the reason for its the higher catalytic performances. 2.On the basis of the previous section, rare earth elements cerium (Ce) has beeninvestigated to modify PtSnln trimetallic catalysts. One of the effect for doping Ce,The CeC>2can greatly increase improve the thermal stability of the catalyst carrier.Cerium can strengthen the interactions between Pt component, promoters, and support.This interaction better inhibits the aggregation of platinum particles and signiifcantlyinhibited the reduction of SnC>2. The performance evaluation results of fourcomponent catalyst show that the optimal Ce loading is1.0wt.%. The right amount ofCe is favor of the reduce depth dehydrogenation reaction. At last, the Ce〇2suppressthe formation of coke on the metal.3.The dehydrogenation performance of platinum-indium catalysts supported oncalcined hydrotalcites carrier is investigated. From several state-of-artcharacterizations, it shows that the Mg-Al composite oxide with low acidity, highthermal stability，large pore size and high mechanical strength properties. Higher ratioof Mg-Al on carrier, MgAl204has higher the degree of crystallinity. Low platinumcontent supported on Mg-Al composite oxide carrier of larger pore size is higherdispersion. Meanwhile, Pt particle is easier access to pores of carrier. The suitableMg-Al ratio can significantly improve the activity of the catalyst. When the ratio ofMg-Al is4-5, the catalyst can get better propylene selectivity and good stability.