Forming MOFs into Spheres by Use of Molecular Gastronomy Methods

A novel method utilizing hydrocolloids to prepare nicely shaped spheres of metal–organic frameworks (MOFs) has been developed. Microcrystalline CPO‐27‐Ni particles are dispersed in either alginate or chitosan solutions, which are added dropwise to solutions containing, respectively, either divalent group 2 cations or base that act as gelling agents. Well‐shaped spheres are immediately formed, which can be dried into spheres containing mainly MOF (>95 wt %). The spheronizing procedures have been optimized with respect to maximum specific surface area, shape, and particle density of the final sphere. At optimal conditions, well‐shaped 2.5–3.5 mm diameter CPO‐27‐Ni spheres with weight‐specific surface areas <10 % lower than the nonformulated CPO‐27‐Ni precursor, and having sphere densities in the range 0.8 to 0.9 g cm^?3 and particle crushing strengths above 20 N, can be obtained. The spheres are well suited for use in fixed‐bed catalytic or adsorption processes.