丙烷脱氢制丙烯Cr_2O_3/Al_2O_3催化剂的失活研究

Deactivation of propane dehydrogenation to produce propylene Cr_2O_3/Al_2O_3 catalysts

以三氧化二铝为载体,通过浸渍法制备了Cr_2O_3/Al_2O_3催化剂并应用于丙烷脱氢制丙烯反应,研究Cr_2O_3/Al_2O_3催化剂的失活原因。借助XRF、强度测试、BET、XRD、TPD、TPR、UV、TG等表征手段考察了新鲜催化剂和使用后催化剂的物性、晶型、酸性、组分作用、价态及积炭的变化。结果表明,随着Cr_2O_3/Al_2O_3催化剂的长时间使用,活性组分三价铬离子和氧化铝晶相发生变化且催化剂表面的活性组分三价铬离子逐渐由催化剂表面进入催化剂的体相,导致晶型转变,进而导致催化剂的活性降低。

Using Al2O3 as the carrier,Cr2O3/Al2O3 catalyst was prepared by impregnation and used in propane dehydrogenation to produce propylene reaction,the cause of deactivation of Cr2O3/Al2O3 catalysts was studied.The physical properties,crystal structure,acidity,component action,valence state and carbon deposition of the fresh Cr2O3/Al2O3 catalyst and the catalyst after used were investigated by XRF,strength test,BET,XRD,TPD,TPR,UV,and TG.Results showed that with the long-term use of Cr2O3/Al2O3 catalyst,the active component Cr3+and alumina crystal phase changed and the active component Cr3+on the catalyst surface gradually entered the bulk phase of the catalyst from the catalyst surface,resulting in crystal transformation.This in turn led to a decrease in the activity of the catalyst.