One-pot hydrothermal synthesis of nanostructured ZrAPSO-34 powder: Effect of Zr-loading on physicochemical properties and catalytic performance in conversion of methanol to ethylene and propylene

Abstract

Nanostructured ZrAPSO-34 catalyst was successfully synthesized via hydrothermal method and Zr isomorphously was substituted into the framework of SAPO-34. The effect of various Zr loadings on the physicochemical properties and catalytic performance was investigated. The structure of the synthesized catalysts was characterized using XRD, FESEM, EDX, BET, FTIR, NH3-TPD and DR-UV-Vis techniques. For samples with low Zr content, relative crystallinity increased and intact CHA structure produced. However, by further Zr loading, relative crystallinity strongly reduced. Acidity results confirmed that Zr incorporation led to increase in both acid sites concentration and strength. Characterization results confirmed the successful incorporation of Zr into SAPO-34 framework. ZrAPSO-34 and SAPO-34 catalysts were applied in methanol to olefins reaction. The Zr incorporation and Zr content have significant effects on the lifetime and product selectivity. For the samples with low Zr content, catalytic lifetime was prolonged compared to the sample synthesized without metal. However by increasing Zr loading, it was reduced and methane selectivity was increased.