Densification of Silica Spheres: A New Pathway to Nano‐Dimensioned Zeolite‐Based Catalysts

Abstract: Nanosized materials are expected to play a unique role in the development of future catalytic processes. Herein, pre-prepared and geometrically well-defined amorphous silica spheres are densified into silica-rich zeolites with nanosized dimensions. After the densification, the obtained nanosized zeolites exhibit the same spherical morphology like the starting precursor but characterized by a drastically reduced size, higher density and high crystallinity. The phase transformation into crystalline zeolitic material and the densification effect are achieved via a well-controlled steam assisted treatment of the larger precursor particles so that the transformation process proceeds always towards the center of the spheres, just like a shrinking process. Furthermore, this procedure is applicable also to commercially available silica particles as well as aluminum containing systems (precursors) leading to acidic nano-catalysts with improved catalytic performance.