The Known and Overlooked Sides of Zeolite-Extrudate Catalysts

Zeolite-based catalysts play the essential roles in the production of fuel and commodity chemicals for the modern society. In general, the main component of zeolites powder has to be transformed into particular shapes in order to match the overall imperatives properties for the industrial applications. Shaping of zeolites catalysts was once only considered as the scale-up or size-enlarging processes of their innovated-form. From the viewpoint of fundamental research, the shaping process was mainly defaulted as a mixing-fabrication process at the macroscopic level without alterations to the intrinsic active sites at the molecular level. Such understandings have been already updated by a series of pioneering investigations by the innovative characterization techniques and methodologies. In the case of the zeolites extrudates, the mutual interactions among the binder, zeolite, and other functional additives, plus their consequences on the new acidities and porosities, have been unprecedentedly confirmed and visualized. Besides these significant achievements, the overlooked zeolites extrudates catalysts are related to the supported metal/metal oxide catalysts. This review further highlights the significant impacts of binders on the catalytic performance of zeolite-based catalysts for the selected catalytic processes. The exemplary processes of hydrocarbon transformations (hydroisomerization and metathesis) show significant dependences on the introduction of binders, which are closely related with the competitive effect or synergetic effect in the dispersion or transformation of active sites for the reactions. The ever-increasing disclosure of the overlooked sides may deepen and widen the understandings of the insights into the shaped zeolites catalysts.

Automated summary

Zeolite-based catalysts are crucial for the production of fuel and commodity chemicals, and the shaping process significantly impacts the catalytic performance, with binders playing a key role in both shape transformation and catalytic properties.