Pentacoordinate Al^(3+)(Al^(3+)_(penta))sites on alumina(Al_(2)O_(3))could anchor and stabilize the active site over the cata-lyst surface.The paper describes the specific effect of Al^(3+)_(penta) sites on the struct...Pentacoordinate Al^(3+)(Al^(3+)_(penta))sites on alumina(Al_(2)O_(3))could anchor and stabilize the active site over the cata-lyst surface.The paper describes the specific effect of Al^(3+)_(penta) sites on the structure and the catalytic performance of Al_(2)O_(3)supported Pt catalysts by modulating the quantity of Al^(3+)_(penta) sites.The Al^(3+)_(penta) site content of Al_(2)O_(3)exhibits a volcano-type profile as a function of calcination temperature due to the structural rearrangement.The loading of Pt and subsequent calcination can consume a significant portion of Al^(3+)_(penta) sites over the Al_(2)O_(3)support.We further find that,when the calcination temperature of the impregnated Al_(2)O_(3)is higher than the cal-cination temperature of Al_(2)O_(3)precursor,the structural rearrangement of Al^(3+)_(penta) sites could make Pt partially buried in Al_(2)O_(3).Consequently,this partially buried structure leads to relatively low conversion but high stability for propane dehydrogenation.This work further elucidates the stabilization mechanism of the Al^(3+)_(penta) site over Al_(2)O_(3)support.展开更多
基金We acknowledge the National Key R&D Program of China(2021YFA1501302)the National Natural Science Foundation of China(22121004,U1862207,22122808)+1 种基金the Haihe Laboratory of Sustainable Chemical Transformations(CYZC202107)the Program of Introducing Talents of Discipline to Universities(BP0618007)for financial support.
文摘Pentacoordinate Al^(3+)(Al^(3+)_(penta))sites on alumina(Al_(2)O_(3))could anchor and stabilize the active site over the cata-lyst surface.The paper describes the specific effect of Al^(3+)_(penta) sites on the structure and the catalytic performance of Al_(2)O_(3)supported Pt catalysts by modulating the quantity of Al^(3+)_(penta) sites.The Al^(3+)_(penta) site content of Al_(2)O_(3)exhibits a volcano-type profile as a function of calcination temperature due to the structural rearrangement.The loading of Pt and subsequent calcination can consume a significant portion of Al^(3+)_(penta) sites over the Al_(2)O_(3)support.We further find that,when the calcination temperature of the impregnated Al_(2)O_(3)is higher than the cal-cination temperature of Al_(2)O_(3)precursor,the structural rearrangement of Al^(3+)_(penta) sites could make Pt partially buried in Al_(2)O_(3).Consequently,this partially buried structure leads to relatively low conversion but high stability for propane dehydrogenation.This work further elucidates the stabilization mechanism of the Al^(3+)_(penta) site over Al_(2)O_(3)support.
