| 초록 |
A gallium-containing ZSM-5 catalyst (Ga/Z), initially prepared with excessive amount of Ga loading, was subjected to acid treatments with various HCl concentrations. A small amount of Ga was found to remain on the post-treated catalysts, whose catalytic properties were investigated and compared to samples prepared via the conventional wetness impregnation method without HCl treatment. While the majority of Ga existed as Ga2O3 particles on the zeolite external surface in samples prepared by wetness impregnation, a substantial portion of Ga was revealed to reside in the zeolite pores of the HCl treated samples. The distinct state of Ga in this sample led to superior catalytic performance in propane aromatization; the sample prepared by the ‘top-down’ method, in which substantial amount of Ga is initially loaded and partially removed afterwards by HCl treatment, showed initial BTX yield of 43.7%, nearly 1.5-folds compared to that of the Ga impregnated sample with identical Ga loading. |
