针对传统浸渍过程中Sn与氧化铝载体易于形成铝酸锡络合物,在反应过程中Pt-Sn合金结构易偏析的问题,利用Al₂O₃择优暴露晶面诱导效应构筑稳定的Pt-Sn/Al₂O₃有序合金催化剂。通过丙烷脱氢性能评价发现,棒状r-Al₂O₃负载的Pt-Sn催化剂形成了均匀且结构稳定的有序合金结构。在560℃时,丙烷初始转化率达68%,丙烯选择性大于97%,远高于其他氧化铝载体负载的Pt-Sn催化剂。利用SEM、STEM和CO-IR等对系列催化剂结构进行表征,结果表明,Pt-Sn/r-Al₂O₃中形成了隔离且电子富集的Pt物种,从而促进了C—H的活化及丙烯的脱附。

Sn and alumina supports are prone to form aluminate tin complexes during traditional impregnation process,thus Pt-Sn alloy structure is prone to segregation.In order to solve this problem,a stable Pt-Sn/ Al₂O₃ ordered alloy catalyst is constructed by means of the induced effect of preferential exposed facets of Al₂O₃.Through the catalytic performance evaluation in propane dehydrogenation,it is found that rod-shaped Al₂O₃ supported Pt-Sn catalyst forms a uniform and structurally stable ordered alloy structure.At 560℃,initial conversion of propane over Pt-Sn/ Al₂O₃ catalyst reaches 68% with a propylene selectivity higher than 97%,far higher than Pt-Sn catalysts supported on other alumina supports.The structures of the catalysts are characterized by means of SEM,STEM,and CO-IR.Results show that Pt-Sn/r-Al₂O₃ possesses the isolated and electron enriched Pt species,which promotes the activation of C—H and the desorption of propylene.

刘雅楠(1990-),女,博士,副教授,研究方向为工业催化,通讯联系人,ynliu@mail.buct.edu.cn。