Pt系催化剂丙烷脱氢结焦性质比较

摘要

Propane dehydrogenation has become an important process for propene production, but the catalyst coking is still an issue in this process. Pt/Al2O3, Pt-Sn/Al2O3 and a commercial dehydrogenation catalyst were tested for propane dehydrogenation and the used catalysts were characterized by XRD, TG, Raman, FI-IR and nitrogen adsorption. The effect of reaction time on coking was investigated. The results reveal that the addition of Sn and K could decrease the coking rate on the catalysts. Sn could transfer the coke from Pt to the support and increase the graphitization extent. Cokes formed on the three catalysts are aromatics and have two dimensional sheet-like structures.%丙烷脱氢是重要的丙烯生产工艺,但催化剂结焦仍是这一工艺存在的重要问题.本文考察了Pt/Al2O3、PtSn/Al2O3催化剂和一种工业催化剂的丙烷脱氢反应性能,利用XRD、TG、Raman、FI-IR、氮气物理吸附等方法对结焦催化剂进行表征,研究了催化剂在不同反应时间下结焦性质的变化.实验结果表明,Sn和K等助剂的引入可以显著降低催化剂的结焦速率;Sn具有转移结焦的作用同时会增加结焦的石墨化程度;三种催化剂上结焦均为芳香烃类物质,具有二维片层结构.