摘要
Elucidating the confinement effect harbours tremendous significance for isobutane alkylation with C_(4) olefin.Herein,the confinement effect over zeolite catalysts was elucidated by combining DFT calculations,experiments(using the novel Beta zeolite exposing only external surfaces(Beta-E)and conventional Beta-I zeolite with both external and internal surfaces)and multi-techniques(e.g.,TGA-DTG,HRTEM,SEM and XRD).It is found that the main active sites for C_(4) alkylation reaction are located on internal surface rather than external surface.On the external surface,the hydride transfer reaction does not occur because the H-shared intermediate cannot be formed without the confinement effect.Moreover,the external surface has stronger selectivity for C_(4) olefin adsorption than isobutane,leading to enhanced oligomerization reactions.Therefore,the suitable micropore with confinement effect is essential for zeolite-catalyzed C_(4) alkylation.The atomic-scale insights of this work are of great referential importance to the design of highly effective zeolite catalyst.
基金
supported by the National Natural Science Foundation of China(21978325,21776312,21908186)
the Independent Innovation Foundation of Qingdao(17-1-1-18-jch)
the Fundamental Research Funds for the Central Universities(18CX02014A)
the Fundamental Research Funds for the Central Universities and the Opening Fund of State Key Laboratory of Heavy Oil Processing(SKLOP202003002).
