From wastes to interconnected porous monolith: Upcycling of Al-based metal organic framework via pickering emulsion template

Abstract : An Al-based Metal-Organic Framework (MOF) obtained from Li-ion battery wastes as an upcycled material has been shaped as a hierarchically porous solid monolith. This original method is based on the stabilization of a Pickering High Internal Phase Emulsion (HIPE) by MOF particles that conducts to the formation of a monolith after polymerization of the aqueous continuous phase and elimination of the organic internal phase of the emulsion. The presence of a small amount of additive polymers rigidifies the monolith structure and an adhesive binder is used to improve the final network porosity of the materials by creating pore throats. This makes the MOFs accessible at the internal surface of the monolith after shaping and keeps some of their original properties. A screening of the different parameters is proposed to optimize the ratio MOF/Polymer/Adhesive binder and retains at best the original properties of the MOFs. This work shows the great ability of MOFs to stabilize Pickering emulsions and to conduct to a solid polymer-MOF composite monolith with interesting properties. We assume that this method can be generalized to other MOFs materials.